Page 184 | Astronomy Magazine (2024)

Table of Contents
‘Oumumamua and the search for life in the universe NASA keeps hiding ‘Easter eggs’ on Mars-bound spacecraft Perseverance’s well-traveled martian meteorite Mars InSight Lander’s secret braille code Curiosity rover’s morse code tire tracks Astronomy reviews Celestron’s NexStar Evolution 8HD telescope, equipped with StarSense Setup and inspection Out under the stars Computer-controlled heavens Galileo’s sunspot sketches get AI-enhanced makeover Deep learning tackles Sun sketches Enhance:Hand-drawn Galileo sketches A long effort finally paying off The Sky This Week: Enter the Snow Moon Are the Egyptian pyramids aligned with the stars? Egyptian pyramids: A gateway to the stars? Pyramid ‘star shafts’ Recent exploration of the pyramids Giza celestial alignments Evidence of ‘lost’ ancient civilizations? In pictures: Relive the 2020 annular eclipse of the Sun A ringed eclipse An unfiltered view leads to a revision Eclipse resources Watch: Fly through the Crab Nebula’s delicate heart In stunning 3D Evolving view Space Force sounds like a joke — and that could be a problem for an important military branch Sci-fi goes in, jokes come out Problems and potential Hidden in plain sight: Scouring the notebooks of the Harvard’s ‘human computers’ History’s ‘hidden figures’ A cosmic fossil record Mapping the stars Exoplanets’ magnetic poles likely wander and flip like Earth’s do Not alone in the cosmos Seeing is believing Posts navigation FAQs References

‘Oumumamua and the search for life in the universe

This widely reproduced illustration of ‘Oumuamua is a huge artistic extrapolation from meager observational data.

ESO/M. Kornmesser

There are three important things you should know regarding that story that just keeps buzzing about the Harvard astronomer who says an alien spacecraft may have passed through our solar system:

• The search for alien intelligence is one of the most compelling and important endeavors in modern science, but…

• …the interstellar object known as ‘Oumuamua is not the long-sought evidence demonstrating the existence of intelligent life elsewhere in the universe.

• And FYI, you don’t have to feel shy about not knowing how to pronounce ‘Oumuamua. Just say, “oh MOO uh MOO uh,” as if you were greeting two cows.

In case you’re not familiar with the story of ‘Oumuamua, here’s a quick recap. In October of 2017, a postdoc researcher named Robert Weryk, working with the Pan-STARRS telescope in Hawaii, detected a peculiar object moving away from the Sun at high speed. Its extreme, hyperbolic orbit indicated that the object was not a member of our solar system. It must have originated from far beyond, somewhere in interstellar space.

Astronomers had inferred that bits of debris from other star systems must transit close to us all the time, but this was first time one of them had ever been observed. The Pan-STARRS team named the object ‘Oumuamua, a Hawaiian word meaning, roughly, “advance messenger from afar.”

‘Oumuamua’s orbit was not the only surprising detail about it. As observers monitored the object, they measured it getting strongly brighter and dimmer, its brightness varying by about a factor of 10. The implication was that ‘Oumuamua has a highly asymmetrical shape, perhaps like a cigar tumbling in space: When we saw the long dimension it appeared bright, when we saw it roughly tip-on it appeared dim. Small celestial bodies often have ragged shapes, but such a strongly elongated form is, well, highly irregular.

The best image of ‘Oumuamua shows just a dot of light, circled in yellow; the dashed lines are surrounding stars that were smeared by the tracking of the telescope.

Credit: ESO/K. Meech et al.

Then there was the issue of ‘Oumuamua’s physical nature. Theoretical models of planetary formation predict that most interstellar objects should resemble comets. Observations of ‘Oumuamua revealed no hint of a comet-like tail, however. So: Maybe it wasn’t a comet. On the other hand, as ‘Oumuamua headed back out of the solar system, it accelerated slightly. That kind of motion commonly happens when comets shoot out jets of gas and dust that were heated by the Sun. So: Maybe it was a comet. But there was still no trace of a tail or any other material escaping, which would make ‘Oumuamua a not-comet that was a comet that did not look like a comet.

Very puzzling!

To place these strange details in context, you should know that the amount of information we were able to gather about ‘Oumuamua was minuscule. It is a tiny object, already extremely faint when it was discovered, observed for just a few weeks. We still don’t know its true shape or its exact composition. We don’t know if it was shedding gases that we simply could not observe. But it was and is undeniably weird — weird enough that Avi Loeb at Harvard wondered if it might be an alien artifact rather than a natural interstellar interloper.

Since 2018, astronomers have lost sight of ‘Oumuamua completely. There’s no more information coming in. There is, however, a new book by Avi Loeb and a flurry of associated media coverage that has rekindled the debate over whether ‘Oumuamua might be evidence of alien technology — and that has sparked a whole new debate about the best way to investigate a claim like that.

From the start, many astronomers criticized Loeb for raising the possibility that ‘Oumuamua could be an alien artifact; several of them regarded his position as one based more on clickbait than on science. Loeb responded by saying that he believed all hypotheses should be open to investigation, and that there was no reason to exclude the possibility of extraterrestrial technology when considering the oddities of ‘Oumuamua. I had a long conversation with him and I largely agreed with him about the value of airing unconventional ideas.

Since then, Loeb has also made outspoken comments that SETI (the search for extraterrestrial intelligence) deserves more attention and more funding. His tone was wildly inappropriate at times, but I agreed with his overall argument here, too. The detection of an alien civilization would revolutionize science, and probably culture, politics, religion, and ethics as well. It’s ridiculous that NASA was effectively blocked from funding any SETI projects after 1992, and only began doing so again last year.

Where Loeb lost me is when he shifted from championing open-mindedness to championing his specific hypothesis about ‘Oumuamua. Of course it is essential to keep looking for unexpected and inexplicable phenomena, and of course we should scrutinize anything that could be a sign of alien intelligence. But that’s a long way from stating, as Loeb does in the introduction to his book Extraterrestrial, that “the simplest explanation for these peculiarities [of ‘Oumuamua] is that the object was created by an intelligent civilization not of this Earth.”

The possibility of extraterrestrial intelligence is so captivating and staggering that it tends to inspire irrational, knee-jerk responses. Normally sober publications like The New York Times published oddly naive essays about the ‘Oumuamua controversy. People with no particular expertise in astrobiology often have strong opinions on the topic of alien civilizations — that they must exist in such a vast universe, for instance, or that the whole topic is ridiculous and unscientific. I find it hard to check my own emotions on the topic, and Avi Loeb appears to have fallen into the trap as well.

An effective tool for returning to sanity is the famous Drake equation. It’s not a equation so much as a succinct summary of all the huge, glorious unknowns in the search for extraterrestrial intelligence. In his book, Loeb calls the Drake equation “nothing more than a heuristic, a shorthand tool.” His description is not inaccurate, but his dismissive attitude is. The Drake equation is a way to make sure we are asking the right questions, and not substituting intuition for actual answers.

The Drake Equation is a formula for estimating the number of detectable alien civilizations. But even more, it’s a way to catalogue the state of our ignorance about the origin of life and the nature of intelligence.

University of Rochester

Each term in the Drake equation sets the conditional probability of the term that comes after. In probability statistics, this concept is known as a Bayesian prior. It is fundamentally nothing more than a piece of information that influences your beliefs about the likelihood of another event.

To give a blunt analogy: Suppose your friend told you that a leprechaun broke into your car and stole it. You’d find that rather hard to believe, and demand some extremely convincing proof. Now suppose that we lived in a world in which we knew that leprechauns were real and that they were commonplace. That additional piece of prior information would make you vastly more likely to believe your friend’s story.

In more subtle (and less ridiculous) ways, the same is true of the terms of the Drake equation. Do most stars have habitable planets? If so, that influences your thinking about the likelihood that some of those planets actually produce life. Is life common throughout the universe? If so, that influences your thinking about the likelihood that some of those planets host sentient beings that could produce space-faring technology.

This concept is the foundation of the familiar dictum, popularized by Carl Sagan, that “extraordinary claims require extraordinary evidence.” In Extraterrestrial, Avi Loeb writes that “it is not obvious to me why extraordinary claims require extraordinary evidence (evidence is evidence, no?).” Prior information is the reason why.

If we already knew that space was full of alien spaceships, the standard of evidence for identifying ‘Oumuamua as one of them would be very low. Given that we don’t know whether life exists anywhere in the universe beyond Earth, the standard is very high. The grand ambition of astrobiology in general, and SETI in particular, is to glean more information about the various aspects of life in the universe, filling in details about each of the factors in the Drake equation.

That said, there is no reason why we need to work through the Drake equation factor by factor, left to right. Every part of it could and should be investigated right now; Loeb is entirely correct on this point. Right now, we know only the first two factors with any degree of confidence. Anything we learn about one of the subsequent factors will inform our understanding of all the others. Every discovery will get us one step closer to answering the existential question of astronomy, and of life in general: Are we alone?

Note, too, that every factor in the Drake equation is a huge mystery in itself. We don’t need to invoke alien spaceships to make this research captivating and personal. We still have so much to learn about life and the universe and our place in the great order of existence.

Consider the 3rd factor, the number of habitable worlds that exist in an average planetary system, and the 4th, the fraction of habitable worlds on which life actually appears. We don’t even know what those numbers are in our own solar system! We might find life on Mars, Europa, and Enceladus and realize that living worlds are extremely common. Or we might find nothing but barren land, and no signs of life on superficially earthlike planets around other stars. Earth might be part of a vast web of cosmic biology, or it might be a rare — even unique — outlier. Either answer would transform the way we view ourselves.

I’m especially fascinated by th 5th factor, the fraction of life-bearing worlds on which intelligence appears. People often whiggishly assume that the natural tendency of evolution is to produce our style of intelligence. But the basic elements for high-level cognition have existed among living things for well over 200 million years, yet hom*o sapiens have been around only about 1/1000th that long. It’s not at all clear that self-aware intelligence is an inevitable evolutionary outcome.

To me, this is the great lesson from ‘Oumuamua, along with all the media hype and scientific gnashing it has inspired: We must keep looking for other intelligence out there in the universe, but we must do it with relentless self-awareness of our biases. Until we have a deeper understanding of where and how life arises, it’s meaningless to claim that an alien spaceship is the “simplest explanation” for the enigma of ‘Oumuamua.

A more honest position is that every astronomical enigma, every inexplicable discovery, is another potential clue. We should keep looking for them, not only because we might discover alien life, but also because we will learn something exciting no matter what.

‘Oumuamua was soon followed by a second interstellar object, Comet Borisov, which looked much more like a conventional solar-system comet. The upcoming Rubin Observatory is likely to discover many more such objects, so soon we will know whether ‘Oumuamua is one of a whole population, or a true outlier. SETI researchers are moving beyond radio, looking for optical signals or chemical evidence of extraterrestrial civilizations, scanning for unusual natural phenomena along the way.

NASA and the National Science Foundation are tentatively restoring support for SETI. Private efforts like Breakthrough Initiatives are jolting the field with new funding and new ideas. The public is clearly captivated by these ideas, which makes it all the more frustrating that we as a society spend so little money investigating such a fundamental question.

‘Oumuamua, faint though it is, can be a beacon to us. It can show us a way to do better and search harder. Not because we think it is likely to be an alien spaceship but because, dammit, if there are alien ships out there — or alien whales or trees or microbes, for that matter — we want to know. We want to unleash the full power of the human intellect to seek out any other members of our cosmic family. But we need to do it with honesty, transparency, and humility.

NASA keeps hiding ‘Easter eggs’ on Mars-bound spacecraft

This annotated image shows how engineers used binary code to hide the message “Dare mighty things” — as well as JPL’s GPS coordinates — in the Perseverance rover’s parachute


On February 18, NASA’s Perseverance rover landed on Mars, ready to embark on a mission to search for signs of ancient alien life. And as the rover descended to the Martian surface, its parachute deployed, revealing a striking red and white pattern that mystified space fans when NASA released the descent images.

“Sometimes we leave messages in our work for others to find for that purpose, so we invite you all to give it shot and show your work,” said NASA’s Allen Chen, lead engineer for Entry, Descent, and Landing Systems, during a press conference.

It didn’t take long for internet sleuths to decipher the hidden message, posting the answer online within hours.

It turned out, the parachute’s strange pattern was actually a binary code message that spelled the phrase “Dare Mighty Things” — the motto of NASA’s Jet Propulsion Laboratory’s motto — as well as listed the lab’s GPS coordinates.

The hidden message comes from a longer Teddy Roosevelt quote, which reads:

“Far better is it to dare mighty things, to win glorious triumphs, even though checkered by failure … than to rank with those poor spirits who neither enjoy nor suffer much, because they live in a gray twilight that knows not victory nor defeat.”

In nerdom, this kind of hidden message is called an Easter egg. The term pops up commonly in video games and software. The first commonly accepted Easter egg appeared in the 1980 Atari video game, Adventure, after the game’s disgruntled programmer hid his name inside the game. Players could only find it if they went to the exact right place. Since then, the term has spread across popular culture, with Easter eggs referring to anything from hidden objects to inside jokes to extra features.

NASA takes this playful tradition to another level, placing Easter eggs not in virtual worlds, but literally on other planets within our solar system. Secret messages like the one on Perseverance’s chute serve as recent examples. However, NASA is also no stranger to attaching sentimental mementos to spacecraft, from New Horizons carrying Clyde Tombaugh’s ashes and Voyager carrying its Golden Record to Juno’s stowaway Lego figurines and the unofficial experiments Apollo astronauts brought to the Moon.

And in recent years, NASA and JPL have turned planting Easter eggs on Mars into something of a tradition.

This meteorite was ejected from Mars millions of years ago and traveled the solar system until it crashed onto Earth and was recovered by humans. Then, NASA eventually sent it on a round-trip visit to the International Space Station before returning a piece of it to Mars on the Perseverance rover.

NASA/JPL-Caltech /LANL/CNES/ESA/Thomas Pesquet

Perseverance’s well-traveled martian meteorite

It turns out, the Perseverance rover is packed with a lot more hidden features than just a cryptic parachute. Over the past week (and before landing, too) NASA has been revealing a number of fun little mementos stashed onboard the rover, such as a family portrait of previous rovers. Perhaps the most poetic, though, is a tiny piece of the Red Planet itself — one that slammed into the Earth’s surface after being blasted from Mars eons ago.

Perseverance was built to search for signs of life on Mars. And one of the main ways it will do that is by using its SuperCam instrument. SuperCam sits on the end of Perseverance’s long-necked mast and uses a combination of a camera, laser, and spectrometer to hunt for organic compounds that may hold evidence of ancient martian life.

So, it’s only fitting that one of SuperCam’s calibration targets contains a piece of a Martian meteorite that’s finally making its way back home. NASA also sent the meteorite sample to the International Space Station for a time before slicing off a piece for Mars. That’s a long, strange trip for a space rock.)

Mars InSight Lander’s secret braille code

NASA’s JPL stashed a message in braille on the Mars InSight Lander’s camera calibration target. You can make it out n the far left and right of the frame, beyond the colored dots.

NASA/JPL-Caltech/Lockheed Martin Space

On every mission before NASA’s InSight Lander touched down in 2018, the space agency had studied things that could be seen on the surface. But InSight took a different approach. It was designed to tune into the rumbles of marsquakes, as well as dig beneath the surface to feel out what was buried below.

So, it was only fitting that the Jet Propulsion Laboratory hid a message in braille on the Mars InSight Lander. Like Perseverance’s parachute, the braille message carries JPL’s initials. The frame that holds it, which is decorated with flags, logos, colored dots, and other unique targets, is designed to be used to test and calibrate the lander’s sensitive cameras. Yet the existence of the braille message slipped by the public until the lander was already on Mars.

Curiosity rover’s morse code tire tracks

The six wheels of the Mars Curiosity rover leave an imprint in the dirt in Morse code that reads “— (J), .–. (P), and .-.. (L)” after JPL, NASA’s Jet Propulsion Laboratory where the spacecraft was built.


When NASA’s Mars Curiosity rover landed on Mars back in 2012, it was far bigger than any other rover that had come before it. The difference was especially obvious in the spacecraft’s wheels, which looked like monster truck tires compared to those on the relatively diminutive Sojourner rover. That’s why space fans back on Earth were quick to analyze the strange tire marks Curiosity left behind after its first test drive on the Red Planet.

It turns out, mission planners had imprinted the rover’s six wheels with a message in Morse code that reads “— [J], .–. [P], and .-.. [L].” JPL is short for NASA’s Jet Propulsion Laboratory, where the spacecraft was built.

However, this wasn’t just a fun way for engineers to write their names in the former beach sands of Mars. Instead, the imprints occur at regular, well-defined intervals, which helps managers back on Earth keep track of the exact distance each wheel travels. That way, they can monitor if any wheels are slipping in steep or loose soil.

Spirit and Opportunity’s World Trade Center relics

Engineers at Honeybee Robotics in Manhattan were working on a key feature of NASA’s Opportunity and Spirit rovers when terrorists attacked the World Trade Center less than a mile away on September 11, 2001. And with the spacecraft’s launch deadline swiftly approaching, the employees couldn’t spend much time helping in the recovery effort. They had to keep building the rovers’ Rock Abrasion Tool, a grinding instrument that would let the spacecraft peel back weathered layers of samples to study what was beneath.

So, working together with JPL engineers, the team found another way to pay tribute. Honeybee Robotics networked with the New York City mayor’s office and secured an aluminum piece of wreckage that they repurposed into identical cable covers for both rovers. And each piece was adorned with an American flag.

The rovers completed their initial 3-month missions on Mars in early 2004, but no one from NASA, Honeybee, or the rover teams mentioned the World Trade Center connection until much later in the year.

“It was meant to be a quiet tribute,” Stephen Gorevan, a Honeybee founder and Mars rover team member eventually told The New York Times. “Enough time has passed. We want the families to know.”

Both Spirit and Opportunity have now shut down, though Opportunity pressed on until a 2018 global dust storm engulfed it. Yet, without significant weather eroding the spacecraft, their metal frames will likely survive for millions of years, creating a permanent memorial on Mars to the lives lost during the World Trade Center attack.

A similar memorial was also tucked away on Perseverance: The rover carries a memorial to healthcare workers and those lost during the COVID-19 pandemic.

Thanks to the hints of JPL engineers, we know Perseverance’s known Easter eggs aren’t the last. The latest rover is still hiding more secrets — and these are expected to be revealed in the coming weeks.

Astronomy reviews Celestron’s NexStar Evolution 8HD telescope, equipped with StarSense

Celestron’s most sophisticated 8-inch SCT ever features a revolutionary system that aligns itself so that users can simply punch in object names and designations on a keypad and slew to thousands of targets.


When I was a teenager, new to observing the sky, I spent a year wandering across the Milky Way armed with nothing more than a pair of 7×50 binoculars. Then a miracle happened: I received a Celestron 8, 1976 vintage, as a birthday present. It changed my universe forever.

From the cornfield behind our Ohio subdivision, the telescope opened up completely new vistas — star clusters, nebulae, and galaxies. Not only could I see hundreds of spectacular sky objects, but I was seeing things like the Veil Nebula, which the old-fashioned literature of the time contended was beyond the reach of an 8-inch scope.
Now I feel like I have undergone another telescope revolution. Last year Celestron celebrated its 60th anniversary. As part of their festivities, they produced a new 8-inch Schmidt-Cassegrain Telescope (SCT), one that rolls all of the company’s fanciest features into one package.

With a built-in wide-field camera, it aligns itself in a matter of minutes, requiring minimal knowledge on the part of the user. It then slews to any of 40,000 targets within its onboard computer’s database. Its multicoated optics are of the highest caliber, and the three included eyepieces are sensational. This is the ultimate 8-inch SCT of its time, and I was happy to be able to put it through its paces over the past few weeks.

The telescope’s carbon-fiber tube is both lightweight and very strong, giving this model a high-tech appearance.


Setup and inspection

Assembly was relatively straightforward, and a helpful booklet walks owners through the process. I went slowly, read everything carefully, and within an hour had everything set up in my living room for inspection, charging of the onboard battery, and preparation for a night of observing.

With the telescope assembled, I couldn’t help but be struck by its quality and elegance. It features a carbon-fiber tube; multicoated, high-transmission optics (what Celestron calls “Edge HD”); a sturdy single-arm mount; and, of course, the alt-azimuth mounting enabled by the computer control of the scope. The company seemingly spared no details: The machining is top-notch and the hardware is solid, a 2″ focuser and star diagonal came along with the package, and the tripod is heavy duty. The onboard battery holds a charge for more than 10 hours at a time. The included eyepieces are very nice, with a 2″ 32mm “porthole” for deep-sky observing and higher-power 11/4″ eyepieces of 15mm and 9mm focal lengths.

The StarSense system was really what intrigued me. I am an old-school, star-hopping guy who has taken great pride in learning the sky and finding objects manually for years. Would this computer-controlled system with its database of tens of thousands of objects — which it would apparently use to align itself before hopping between galaxies — win me over?

Celestron’s StarSense system uses a remarkable wide-field camera to image star patterns around the sky, allowing the telescope to understand where it is and how it’s aligned before automatically slewing to a target.


Out under the stars

The first thing you need to do with this scope is set it up on level ground and run a program that enables the StarSense unit to calibrate itself. Included instructions and a link to an online video tutorial make that very simple. That first night I was in a hurry, so I set it up on my driveway to give it a quick run-through. Although a portion of the sky was blocked by a tree and the house, I was curious to see what would happen.

So began my adventure with StarSense Autoalign. The camera mounts atop the scope’s tube with a heavy bracket and plugs into a port on the mount. To begin the calibration procedure, you start with the scope’s tube positioned horizontally. A hand controller allows you to input choices and, once the scope is aligned, target countless objects. I uncorked the scope’s mirror, the StarSense camera’s cover, and the diagonal’s cover before plopping a very nice E-lux 32mm Celestron eyepiece into the diagonal.

I powered the scope on, chose “Align” on the hand controller, set the time, date, and time zone, then stepped back and watched. Over the course of about 10 minutes, the scope slewed to and fro and occasionally noted on the controller that it had imaged a certain number of stars. Would this work with the handicap I gave it in my rush to test the scope? After a short time, “Alignment complete” came up on the controller.

Next, I followed the protocol by calibrating on a known star. I punched in “Vega” and the scope immediately slewed upward, capturing Vega’s position. When I peered into the eyepiece — low power, no doubt — the star was dead center. The final step is a calibration on the star itself (Vega in my case), and this can be done with a high-power eyepiece to maximize precision. You can then realign the StarSense and, in another few minutes, the mount is ready to use all night; you can simply punch in targets and let the scope slew to them.

This full calibration procedure needs to be performed only once, when the StarSense Autoalign is first attached to the telescope’s tube. From there, a full calibration is not needed unless the StarSense is bumped or the bracket removed.

Wow. Here is the kind of telescope that could revolutionize astronomy. This is a telescope that anyone can use without any knowledge of old-style polar alignment. It is really quite amazing to see this work just as magically as is advertised, with objects showing up dead-centered, just as requested from the database.

The scope’s standard visual back employs a 2″ star diagonal and can accommodate both 2″ and 11/4″ eyepieces.


Computer-controlled heavens

I gave this telescope a more thorough test run from my backyard in Wisconsin, where I can see the Milky Way and a good smattering of faint stars. The telescope performed most impressively. I can’t wait to get it underneath a really prime sky like that of southern Arizona.

I commenced my journey with Jupiter and Saturn, each looking really fine, with nice cloud details, even at low power. All the moons that should have been present were, and the higher-power eyepieces provided a splendid view early on, even though the seeing had not fully settled down for the evening.

But I was eager to tour deep-sky objects and so I plopped the 32mm eyepiece back in and went to work. Everything I looked at showcased the quality of the telescope’s optics — the views were crisp and well defined, and I saw all the details in clusters, nebulae, and galaxies that I would expect to see from a suburban site. The 32mm eyepiece provides a sharp, flat field, yielding crisp stars all across the view.

The Lagoon Nebula did not disappoint, with its gauzy areas of bright gray-green nebulosity and the sparkly, well-populated star cluster NGC 6530. For a time, I walked up the line of bright clusters and nebulae in Sagittarius and Serpens. Only needing to input the numbers of Messier and NGC objects makes one spoiled quickly. There was the Trifid, glowing faintly; the unmistakably bright Omega Nebula popped fiercely, and the delicate light of the Eagle Nebula appeared well defined. The computer-controlled database makes punching in some of the lesser-known objects like clusters M23, M25, and NGC 6603 easy. I worked my way up to M11, which was incredible, and then viewed some globulars — M22 in particular was a killer, looking quite photographic.

Celestron supplies an array of accessories with this scope, allowing users to enjoy a luxurious telescopic experience.


I turned toward some favorite planetary nebulae I hadn’t viewed in a while. The Dumbbell Nebula, high in the sky, knocked my socks off — it looked like a glowing photo in a rich starfield of colorful suns. What incredible beauty. But Cygnus and Aquila had many other treasures, and I viewed NGC 6781, NGC 6894, NGC 7008, and NGC 6826 (just to name a few). They all appeared quite well defined, with the blue-green colors showing well, and were visible at low powers, growing more spectacular as I increased magnification.

I then took a shot at some widely scattered objects just to see the range of views the telescope could provide. The Andromeda Galaxy appeared bright and oval, with well-defined dust lanes close to the nucleus. The Owl Cluster in Cassiopeia, with its bright deep yellow chief sun, was an old friend I revisited. Double stars like Mizar and Albireo were simply stunning, set in black starfields, and galaxies like M81 and M82 floated majestically in space.

As the night went on, I found this telescope to deliver on everything I had hoped for: The optics are sharp, the accessories luxurious, the tripod overbuilt and very stable, the craftsmanship of the optical tube and the electronics first-rate. I have a soft spot for the old 1976 Celestron 8, with which I made my initial thousands of observations, and which is now in my basem*nt. But there’s a new Celestron in town, and this magnificent model is going to be hard for any such portable instrument to overcome. This is a telescope for a new age of amateur astronomy.

Galileo’s sunspot sketches get AI-enhanced makeover

This image from NASA’s Solar Dynamics Observatory shows the Sun in extreme ultraviolet (UV) light at a wavelength of 171 angstroms. Active sunspot regions appear bright in UV light as the Sun’s twisted magnetic field heats its upper atmosphere.

NASA/Goddard Space Flight Center Scientific Visualization Studio

In the summer of 1612, Galileo Galilei turned his telescope to our closest star, the Sun, projecting its image safely onto a screen. To his surprise, he found its surface was blotted by small dark spots that moved across its face. Although he was not the first to discover such sunspots, his hand-drawn sketches are still some of the earliest surviving drawings of them.

Today, of course, astronomers have much more advanced methods for observing the Sun. Ground-based and satellite imagery captures the Sun in multiple wavelengths, revealing the complex structures of its sunspot-creating magnetic field — details that would have eluded Galileo and his visual observations.

But now, thanks to the artificial intelligence deep learning — as well as a long-running campaign of hand-drawn solar sketches that continues in California to this day — a team of scientists at Kyung Hee University in Seoul, South Korea, have reconstructed what Galileo’s Sun would have looked like if it were observed by modern satellites. The AI-generated images are not perfect, but they still could be used to glean information about the strength of the Sun’s magnetic field in those sketched regions hundreds of years ago.

The work was published in The Astrophysical Journal on February 5.

Deep learning tackles Sun sketches

The model they created is a neural network — an algorithm that is trained on a large amount of data to learn the task it is supposed to perform. In this case, the Kyung Hee team wanted to feed the model sunspot sketches, which capture only the visual appearance of the Sun’s surface. The algorithm would then spit out the kind of images that NASA’s Solar Dynamics Observatory (SDO) satellite would capture of such sketches in various bands of ultraviolet light, where active sunspot regions glow brilliantly.

At left is an example of a Mount Wilson sunspot sketch from June 6, 2014. At right is the corresponding magnetogram recorded by SDO.

Lee et al. (2021)

Those kinds of images can reveal information about the state of the Sun’s magnetic field. That’s because unlike the relatively simple magnetic field of the Earth, which more or less resembles that of a planet-sized bar magnet, the Sun’s magnetic field is a complex mess of looped and knotted strands that arc above the star’s visible surface. The energy trapped in these twisted magnetic field lines creates sunspots on the Sun’s visible surface by suppressing energy welling up from within. This makes those areas cooler and, therefore, darker in visible light. But it also serves to heat gas high in the Sun’s atmosphere, creating the scorching, glowing areas seen in UV images.

“We thought that although sunspot drawings have limited information, if we provide enough data to a deep learning model, it can generate solar images similar to the SDO observation data,” co-authors Harim Lee and Yong-Jae Moon told Astronomy in an email.

Enhance:Hand-drawn Galileo sketches

In order to provide the model with a training dataset, they turned to the archives of Mount Wilson Observatory outside of Los Angeles. There, on nearly every clear day since the observatory’s historic 150-foot-tall (46 meter) solar observing tower opened in 1912, an observer makes a hand-drawn sunspot sketch.

Lee, Moon, and their colleague Eunsu Park took the sketches made from 2011 to 2015 and feed them into the algorithm, along with the actual corresponding UV images from SDO. They also provided the model with SDO magnetograms, which are maps of the Sun’s magnetic field strength that indicate the polarity of the field at active regions.

In these image pairs, the actual pictures from NASA’s SDO are on the left. The AI-generated recreations — based on Mount Wilson sunspot sketches — are on the right.

Lee et al. (2021)

The resulting model manages to generate UV images that are striking in their similarity to the real deal. And in the generated magnetograms, the model reproduces a characteristic signature of active sunspot regions — side-by-side patches of opposite polarity — even though the model has no knowledge of the physics involved.

Since Galileo made several weeks’ worth of sketches tracking changes in the Sun’s surface, the team was able to use the model to calculate how magnetically active these regions were at the time, how they evolved, and how they would look to modern satellites.

But giving Galileo’s sketches a facelift isn’t the only thing the new model can do. Lee and Moon hope that it can also help them analyze other historically significant solar storms captured in other sunspot sketches — like the Carrington event of 1859 — acting as a bridge between historical records and modern satellite observations.

At left is Galileo’s sunspot sketch for June 2, 1612. At right are the resulting satellite pseudo-images that the AI model generated — how the Sun may have appeared, if the technology existed at the time to see it.

Lee et al. (2021)

A long effort finally paying off

The work is “very interesting,” says Roger Ulrich, the director of Mount Wilson’s the 150 foot solar tower. “Their first step is obviously to demonstrate that the method basically works — and they did that. So it would be interesting to see how far they can carry it.”

For Ulrich, this work is the start of something he has long hoped would come from he and his staff’s efforts to maintain and digitize the sunspot sketch archive. “The idea of going back and kind of resurrecting old global magnetogram structures for the Sun has always intrigued me as something that would be valuable,” he says. “The sunspot drawings have some of that information, but obviously not enough of it without this other AI approach.”

One limitation of the model, however, is that it doesn’t reproduce non-active regions of the Sun with weak magnetic fields, which Ulrich says would be necessary to get a comprehensive picture of the Sun’s magnetic field at any given moment, past or present. Though he admits it might not be possible to solve, he adds “it certainly would be worth checking out.”

Unfortunately, Ulrich and his team were forced to cease their research operations at the 150-foot solar tower back in 2012 due to equipment failures and a lack of funding. But a volunteer observer, Steve Padilla, still climbs the tower every clear day to make a sunspot sketch, which is posted online each day. But Ulrich says it’s gratifying to see the digitized data — which go back to 1967 and took about three years to process — be useful.

“That’s part of why I wanted to get the drawings out there to people,” says Ulrich. “I am glad that the availability of the data has helped the community like this.”

The Sky This Week: Enter the Snow Moon

Super Snow Moon

The February Full Moon is also called a Snow Moon. This Full Moon appeared in the sky last year, on February 8, 2020. The event coincided with our satellite’s perigee, meaning it was also a Super Moon.

Giuseppe Donatiello (Flickr)

Friday, February 26
Monoceros the Unicorn sits sandwiched between Orion’s two hunting dogs, Canis Major and Canis Minor. You’ll find it sinking in the southwest one to two hours after sunset — but before this region disappears, take some time to hunt down some of the many open star clusters that lie within its borders.

First try for NGC 2286, which shines at magnitude 7.5 and is located a little over 6° northeast of magnitude 5 Beta (β) Monocerotis. A small scope will reveal roughly 30 stars covering a region 15′ across, including the cluster’s two brightest stars: a double system separated by 34″, whose components both shine around magnitude 10.

Once you’ve mastered that challenge, move on to NGC 2311. This cluster is magnitude 9.6 and floats about 1.5° southwest of a different magnitude 5 star: 19 Monocerotis. NGC 2311 is a bit smaller, covering only 7′. Only its brightest 15 to 20 stars are visible through a 4-inch scope; you’ll need 8 inches to double that amount.

Finally, seek out magnitude 7.2 NGC 2335, similar in angular size (7′) to NGC 2311. Although this cluster is still within Monoceros’ borders, the nearest bright signpost is magnitude 4 Theta (θ) Canis Majoris in the Big Dog. NGC 2335 is about 3.5° northeast of this star. A magnitude 7 field star, SAO 134220, lies near the cluster’s core, just 8′ to its northeast. A small scope will net you about 20 cluster stars, but you’ll need something much larger — 12 inches — to double that number.

Sunrise*: 6:37 A.M.
Sunset: 5:49 P.M.
Moonrise: 5:11 P.M.
Moonset: 6:37 A.M.
Moon Phase: Waxing gibbous (99%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 12 P.M. local time from the same location.

Saturday, February 27
Full Moon occurs at 3:17 A.M. EST. As February’s Full Moon, it’s also known as the Snow Moon. Our satellite will still be 99 percent lit this evening, when it’s rising as the Sun sets. Because the Full Moon is so bright, it’s difficult to observe deep-sky objects during this phase. But at the same time, the Moon makes an excellent target for beginning and experienced observers alike.

When the Moon is Full, its nearside is experiencing noon — the Sun appears high in the sky for an observer on the lunar surface, which can admittedly wash out some of our satellite’s more subtle detail. But all its seas — or maria — are on exquisite display, showing us exactly where lava once flowed across the surface. These seas are relatively young — 3.8 billion years or younger — because otherwise, they’d be fully covered in craters by now.

The lighter areas that surround the seas are called highlands. These regions have undergone heavy cratering and appear much more rugged and pockmarked. Some of the Moon’s largest craters are also easily visible, including Tycho in the south, Copernicus in the (lunar) west, and Plato in the (lunar) northwest.

Sunrise: 6:36 A.M.
Sunset: 5:50 P.M.
Moonrise: 6:23 P.M.
Moonset: 7:10 A.M.
Moon Phase: Full

Sunday, February 28
The morning triangle of planets formed by Mercury, Jupiter, and Saturn has been flattening over the past several days as Mercury’s declination drops. But at the same time, the tiny planet is growing brighter and easier to see against the twilight sky.

Mercury, now magnitude 0.3, stands a mere 3° west of Jupiter this morning. Saturn is now 5.5° to Mercury’s west. All three are located in Capricornus, slightly southeast of where the Sun is rising. Try viewing them about half an hour before sunrise, taking care not to use any optics — such as binoculars or a telescope — within a few minutes of when the Sun is scheduled to appear at your location.

Looking at these planets gives you a view out through the solar system. All three are currently on the far side of the Sun from our viewpoint. Mercury is closest to Earth at 0.85 astronomical unit, where 1 astronomical unit, or AU, is the average Earth-Sun distance. Next in line is Jupiter, which sits 6 AU away, and lastly is Saturn, at 10.8 AU.

Sunrise: 6:34 A.M.
Sunset: 5:51 P.M.
Moonrise: 7:37 P.M.
7:40 A.M.
Moon Phase: Waning gibbous (97%)

Red and blue

On March 30, 2019, Mars approached within 3.3° of the Pleiades star cluster in Taurus the Bull. A thin layer of clouds diffused the light from the Red Planet, producing the halo.

Ayman Naguib

Monday, March 1
Mars opens the month of March a mere 3° due south of M45, better known as the Pleiades. This sparkling open star cluster is easy to spot with the naked eye in the constellation Taurus, already relatively high in the southwest by the time full darkness falls.

The Red Planet now spans just 6″, making it a disappointing telescopic object if you’re looking for detail. If you are an experienced observer, video capture might net you some surface features.

But it’s still a great bright target for beginning observers eager to explore our solar system from their backyard. Its magnitude 0.9 glow is just the tiniest bit fainter than nearby Aldebaran, a magnitude 0.8 red giant in the Bull’s face that sits among — but is not properly part of — the loose Hyades open cluster.

Sunrise: 6:33 A.M.
Sunset: 5:52 P.M.
Moonrise: 8:49 P.M.
Moonset: 8:09 A.M.
Moon Phase: Waning gibbous (92%)

Tuesday, March 2
The Moon reaches perigee — the closest point to Earth in its slightly elliptical orbit — at 12:18 A.M. EST. At that time, it will sit 227,063 miles (365,422 kilometers) away.

Draco the Dragon sits with his head low to the northern horizon after sunset tonight, but by two hours after the Sun disappears, the magnitude 3.6 star Thuban is nearly 30° high and rising. This seemingly nondescript star has a famous past — it was once the North Star, sitting where the current pole star, Polaris in Ursa Minor, is now located.

That past role is likely the reason Thuban is Draco’s alpha star, despite the fact that it’s fainter than many of the Dragon’s other luminaries. Its name also, curiously, means “the serpent’s head” in Arabic, despite its location in Draco’s tail.

These days, Draco is a circumpolar constellation, meaning it circles the North Celestial Pole. If you stay out late enough, you’ll see the stars of Draco ascend in the sky and then begin arcing back over again as Earth rotates.

Sunrise: 6:31 A.M.
Sunset: 5:53 P.M.
Moonrise: 10:03 P.M.
Moonset: 8:38 A.M.
Moon Phase: Waning gibbous (85%)

Wednesday, March 3
A bright Moon sits near the border of Libra and Virgo tonight, washing out much of the sky after midnight. But there’s still plenty to see. Around 4 A.M., early risers can enjoy the large open cluster M11, also known as the Wild Duck Cluster. Located in Scutum, it’s roughly 20° high two hours before sunrise and rising. Through binoculars, you’ll see a fuzzy patch of light, easily findable with a magnitude of 6.3.

Discovered in 1681, this cluster gains its nickname from the rough V shape formed by its brightest stars, which look a bit like a flock of wild ducks flying overhead. In reality, however, the cluster contains around 3,000 stars, many of which will pop out once you train a telescope on the region.

Sunrise: 6:30 A.M.
Sunset: 5:55 P.M.
Moonrise: 11:17 P.M.
Moonset: 9:09 A.M.
Moon Phase: Waning gibbous (75%)

Thursday, March 4
Asteroid 4 Vesta is at opposition today at 1 P.M. EST. You can find it in the constellation Leo tonight — the main-belt asteroid is now one of the top 10 brightest lights in the Lion’s hindquarters.

Look east and find the right triangle formed by Chertan, Zosma, and Denebola. Tonight, Vesta (around magnitude 6) sits just 1.2° northeast of magnitude 3 Chertan — within one binocular field of view. If you plot the three bright stars on a piece of paper and come back from night to night, you’ll definitely notice Vesta inching along, heading northwest against the background stars.

Vesta, as its number indicates, was the fourth body discovered in the asteroid belt. At roughly 300 miles (480 km) across, it’s half the size of dwarf planet 1 Ceres. The Dawn mission visited both worlds about a decade ago, sending back detailed images and information about them — including evidence that some meteorites we find today on Earth are pieces blasted off the surface of Vesta by past collisions.

Sunrise: 6:28 A.M.
Sunset: 5:56 P.M.
Moonset: 9:43 A.M.
Moon Phase: Waning gibbous (65%)

Irresistible Orion

The Orion Nebula is one of the sky’s most brilliant gems. Visible even with the naked eye, this extremely photogenic region bursts with detail in long exposures.

George Greaney

Friday, March 5
Take some time tonight to enjoy one of the best jewels the cosmos has to offer: the Orion Nebula (M42).

With no Moon in the sky after dark, look southwest to find the familiar three stars of Orion’s belt. These are, from left to right, Alnitak, Alnilam, and Mintaka. About 3.7° southwest of Alnitak is a fuzzy region you can see without any optical aid at all — that’s the nebula. It glows equivalent to a magnitude 4 star and actually covers a region of the sky about six times the width of the Full Moon in total.

Binoculars or, even better, a telescope will reveal a wealth of detail, showing delicate structure in the gently glowing gas of the nebula. A telescope will clearly show the stars of the Trapezium Cluster — several young, bright, hot stars blasting out ultraviolet radiation, which is slowly eroding the nebula in which they sit. Can you make out a darker cavity around these stars, where the gas has already been blown away? Eventually, the Trapezium stars (and others you cannot see) will completely blow away their birthplace, leaving an open cluster like the Pleiades, the Hyades, or the Wild Duck.

Sunrise: 6:27 A.M.
Sunset: 5:57 P.M.
Moonrise: 12:30 A.M.
Moonset: 10:22 A.M.
Moon Phase: Waning gibbous (54%)

Are the Egyptian pyramids aligned with the stars?

Some researchers suggest the Giza pyramids were built in alignment with the stars. But that idea has been met with criticism.

Wikimedia Commons

Do the Egyptian pyramids line up with the stars?

This idea gets tossed around so often that many ancient Egypt fans simply accept it as true. And on the surface, it seems plausible. The ancient Egyptians tracked the night sky closely. They studied the constellations and used the motion of the stars to make decisions about when to plant crops and when to harvest. But there’s been a long debate over whether the pyramids themselves are actually aligned with any particular set of stars.

Over the decades, researchers have proposed a handful of possible celestial alignments for the pyramids, especially with the Giza Pyramid Complex. This famous site outside Cairo includes the Great Sphinx and three main pyramids: the Pyramid of Menkaure, the Pyramid of Khafre, and the Great Pyramid of Giza.

But the pyramids were built in the decades around 2500 B.C., during a period called the Old Kingdom of Ancient Egypt. So, any celestial alignment they have with the night sky would have to match what the heavens looked like some 4,500 years ago.

Egyptian pyramids: A gateway to the stars?

Theories about the pyramids’ connection to the stars go back a long way. But in the 1980s, a researcher named Robert Bauval came up with a suggestion that has since buried itself in the minds of the public. He pointed out that there are similarities between the layout of the three pyramids of the Giza Complex and the relative separation between the three stars of Orion’s Belt in the constellation Orion.

The idea went mainstream in Bauval’s 1995 New York Times bestseller, The Orion Mystery, which expanded on the notion that “the pyramids were created to serve as a gateway to the stars.” Bauval claimed that the constellation Orion governed the construction of all the pyramids. His idea came to be known as the “Orion correlation theory.”

Today, it’s considered a fringe idea in archaeology. Why? There’s no physical evidence to prove an intentional correlation. Plus, there’s nothing in Egpytian texts indicating the pyramids were intentionally designed that way.

Critics instead say that believers are succumbing to pareidolia — the human tendency to see shapes, patterns, and meaning in objects, even when no pattern exists. For example, seeing the face of the famous Man in the Moon.

The three pyramids weren’t all planned at once, either. The Pyramid of Menkaure, which is much smaller and sits a little farther away, seems to have been an afterthought, according to leading researchers. So, it’s a reasonable to think the distances between the monuments had no connection to the spacing between of the three stars of Orion’s Belt. Or, at least, no intentional connection to the stars.

Besides the lack of proof, the Orion Correlation Theory typically draws rolled eyes because it’s often packaged with other unusual claims. The people who defend the idea most passionately are usually the ones also championing tales of ancient aliens and forgotten technologically advanced cultures.

Pyramid ‘star shafts’

Since their discovery, scientists have debated whether these interior shafts in the Great Pyramid of Giza are “air shafts,” or rather “star shafts” made to align with constellations. Wikimedia Commons

The Orion Correlation Theory grew from researchers’ interpretations of two mysterious, narrow shafts discovered in the Great Pyramid of Giza. These shafts extend from the so-called “King’s Chamber” into the pyramid’s walls. Some experts have suggested they are air shafts. But it’s unclear why the dead would need access to oxygen. Other researchers, however, think these tunnels served as pathways to heaven.

And in the 1960s, a group of Egyptologists suggested that these were actually star shafts, built to point toward important stars and constellations. Two researchers, Virginia Trimble and Alexander Badawy, found that one of the shafts seems to aim in the general direction of where the north star would’ve been when the pyramids were constructed. The other shaft, generally, points toward Orion’s Belt. These two sections of the sky were also known to be important in ancient Egyptian mythology.

The pole stars, including the north star, were known as “imperishable stars,” or “the indestructibles.” The Egyptians tied these unflinching stars with their beliefs about the afterlife, and thought their deceased pharaohs would join them there. “I [the king] will cross to that side on which are the Imperishable Stars, that I may be among them,” one passage reads. Similarly, Orion was also important to ancient Egyptian culture because its stars represented Sah, the father of the Egyptian gods.

The shafts likely wouldn’t have been useful for actually observing these objects, though. They were roughly oriented, with horizontal sections and large stones blocking their exit. But despite a number of attempted shaft explorations, the mystery of their true purpose has persisted for more than half a century.

Recent exploration of the pyramids

In 2020, researchers from Leeds University in the United Kingdom announced they had developed a small robot in an attempt to settle the shafts’ purpose once and for all. The robot successfully navigated through all 200 feet (60 meters) of one shaft, collecting nine hours of video footage along the way.

But a surprise was waiting for them at the end of the tiny tunnel. The robot was able to get a camera past the intentionally placed stone blocking the shaft, allowing it to discover a small chamber with elaborate symbols drawn on the floor. But beyond that, there was a second stone the robot couldn’t get around.

“Given the artwork, it is likely the shaft served a bigger purpose than act[ing] as an air vent,” Rob Richardson, a robotics professor at Leeds University and the project’s technical lead, said in the initial announcement of the discovery. “What lies beyond that second stone, at the end of the shaft, is a question that remains unanswered. The mystery of the Great Pyramid continues.”

Ultimately, the team cut their project short in Egypt after security concerns grew within the country.

This 1938 aerial image shows the pyramids and the Nile River Valley. Wikimedia Commons/American Geographical Society Library, University of Wisconsin-Milwaukee Libraries

Giza celestial alignments

Beyond the shafts, there are other possible alignments to consider, too. For example, sunset on the winter solstice falls above the Pyramid of Menkaure as seen from the Great Sphinx of Giza. And the corners of the Great Pyramid of Giza also align well with the cardinal directions — north, south, east, and west. Researchers have spent years trying to understand how the builders were able to align the pyramid so precisely, and most accept that the ancient engineers used the motion of the Sun.

So, it’s clear that the pyramids hold celestial significance and that they were built with a mastery of the sky in mind. Those ideas are not at all controversial. The controversy stems from the notion that each of the three pyramids were specifically positioned and oriented to represent Orion’s Belt. If you look at Bauval’s overlay of the pyramids’ placement and the stars of Orion’s Belt, you can definitely see the similarities. Yet, the alignment still isn’t perfect.

Believers see a connection between the layout of the pyramids at Giza (crossed squares) and stars of Orion (smudgy circles). But critics say the overlap has been distorted. DavkalWikimedia Commons

It also isn’t completely honest. In 1999, astronomers using planetarium equipment exposed some serious liberties taken by proponents of the idea. In order for the pyramids to take the shape of Orion’s Belt, you have to invert one or the other. So, the pyramids don’t really mirror the celestial alignment in the way that’s often presented. What’s more, the stars in Orion’s Belt have moved since the pyramids were constructed, so their relative positions would’ve been different back then.

Evidence of ‘lost’ ancient civilizations?

Furthermore, the theory for a stellar connection with the pyramids veers toward the weird when supporters argue the pyramids still would have lined up with Orion around 10,000 B.C. The problem there is that 10,000 B.C. is several thousand years before Egyptian culture even existed.

Humanity’s oldest known structure that did align with the stars is Nabta Playa, a small stone circle that sits in far southern Egypt and was built by an older nomadic culture. Still, Nabta Playa is just 7,000 years old. There’s also the much smaller structure called Gobekli Tepe in Turkey, which was built some 6,500 years before the pyramids, or roughly 12,000 years ago. But researchers have yet to find any surefire evidence of celestial alignments there.

In addition to most archaeologists already concluding the Orion Correlation Theory is a fringe idea, astronomers have also used computers to determine the past positions of many stars. This made it easy for them to debunk the idea that the pyramids aligned with Orion’s Belt some 10,000 years ago.

Yet, there’s still other popular commentators and authors of books on Egypt, like Graham Hanco*ck, that suggest that the pyramids — and other marvels of the ancient world — are actually relics of a forgotten and technologically advanced ancient civilization. They argue that such a civilization existed long before researchers have found any evidence for cultures that complex. The idea has no scientific merit, but that hasn’t stopped it from boosting TV show ratings and book sales.

And meanwhile, on the Giza Plateau, despite generations of researchers searching for answers, the real life case of the pyramids mysterious “star shafts” isn’t likely to be solved any time soon.

[Editor’s note: This article was updated Jan. 31, 2023.]

In pictures: Relive the 2020 annular eclipse of the Sun

On June 21, the Moon was relatively far from Earth thanks to its slightly elliptical orbit. That meant its angular size was smaller than usual. Therefore, it couldn’t fully block the solar disk when the Sun, Moon, and Earth aligned, or entered syzygy, as shown in this artist’s illustration.

Astronomy: Roen Kelly after Ernest T. Wright (NASA’s Scientific Visualization Studio)

The wild year of 2020 boasted two solar eclipses: an annular eclipse on June 21 and a total solar eclipse on December 14. Travel restrictions prevented North Americans, as well as many others in the Western Hemisphere, from viewing the path of annularity that stretched from Africa through the Middle East to Pakistan, India, mainland China, and Taiwan. Fortunately, local eclipse viewers who managed to get beneath the Moon’s shadow captured wonderful images of the breathtaking event.

The following is a smattering of shots from last June’s annular eclipse, which I monitored into the wee hours of the morning with the help of email, the web, and livestreams from the Middle East and Asia. My decades-long interest in eclipses, and the resulting expeditions I have taken to view them, have allowed me to meet many fascinating people whom I never would have otherwise. And although I don’t keep in constant contact with every one of them, when an eclipse passes overhead anywhere in the world, I have a good chance of hearing from some of my old friends who are eager to share their new pictures.

At the time of this writing, the next solar eclipse to be seen from Earth will be total, with its peak occurring near the border of Argentina and Chile on December 14, 2020. Be sure to keep an eye out for images of December’s total solar eclipse in future issues of Astronomy.

Meanwhile, the next annular eclipse will be on June 10, 2021. Its path will trek from southern Canada over the North Pole and down to the Russian Far East. Observers in the northeastern United States will be happy to learn that partial phases of this annular eclipse will be visible to them in the early morning. So, make sure to get your filtered solar eclipse glasses now, available at

And don’t forget: Share what you see!

The Moon’s shadow first touched the Republic of Congo during the June 21 annular eclipse. After it departed Africa, it went through the Middle East, then passed through southern Pakistan, northern India, mainland China, and Taiwan before vanishing southeast of Guam. The annular eclipse path, which stretched 9,058 miles (14,578 km), was just 13 miles (21 km) wide and maximum eclipse (99 percent) lasted only 38 seconds.

Michael Zeiler

A ringed eclipse

The word annular comes from annulus, which means “ring.” So, when the Moon is just far enough away from Earth that it leaves the outer perimeter of the Sun’s disk unobscured, the result is often referred to as a “ring-of-fire” eclipse. At maximum coverage, this outer band of sunlight is up to a few percent of the solar disk’s diameter. So, technically, it could be called a “ring-of-photosphere” or a “ring-of-sunlight” eclipse.

The term “ring-of-fire” has murky origins dating back at least 150 years, but its modern usage in reference to annular eclipses has been around for at least a few decades, when it started popping up in various publications. However, “ring-of-fire” is somewhat misleading terminology, and it is disliked by many professional and amateur astronomers, or so-called umbraphiles (the umbra is the dark part of a shadow). Contrary to common conception, there is no chemical fire on the Sun. Rather, we owe the warmth and light we receive from the Sun to the clean thermonuclear fusion of hydrogen gas safely occurring some 93 million miles (150million kilometers) away.


An unfiltered view leads to a revision

The June 21 annular eclipse also traced a path through Pakistan, where the cloud-cover forecast was not as favorable as in the lower Arabian Peninsula. Fortunately, it turned out to be very clear.

From Sukkur — a city in the Pakistani province of Sindh — Talha Moon Zia, who is a research astronomer at Pakistan’s National Center for Big Data and Cloud Computing/NED University of Engineering & Technology, obtained these wonderful unfiltered views of the annular eclipse. The shots were created by stacking several short-exposure images and were taken under the guidance of Michael Kentrianakis, the former project manager of the American Astronomical Society’s 2017 U.S. eclipse efforts and a member of our International Astronomical Union’s (IAU) Working Group on Solar Eclipses.

Our IAU group focuses on being a central resource for anyone looking to find out more about past or upcoming solar eclipses. To do this, we maintain a website at the easiest possible address to remember: The working group also serves as a clearinghouse for professionals pursuing international eclipse expeditions, coordinating such matters as visas, customs, and the shipping of equipment.
For these images, Zia and Kentrianakis forwent filters in order to capture detailed views of Baily’s beads, which occur when sunlight peeks through valleys along the lunar limb. This allowed them to successfully detect the solar chromosphere, and even the inner solar corona.

Prior imaging of Baily’s beads taken during previous total solar eclipses led to discussions between me, Xavier Jubier, and Ernest T. Wright of NASA’s Scientific Visualization Studio. We concluded that the IAU’s nominal solar diameter — the defined size of the Sun’s photosphere, which is used for predicting the length of eclipse totalities down to a fraction of a second — needed a minor revision. By comparing our observations to simulations by Jubier of the expected Baily’s beads for this eclipse, which were based on high-resolution 3D mapping of the lunar surface obtained by NASA’s Lunar Reconnaissance Orbiter and the Japanese Kaguya mission, we found our suspicions were confirmed.

Zia’s observations, as well as Jubier’s simulations, show the true size of the Sun’s photosphere is slightly larger than previously thought.

Eclipse resources

Many observers who were unable to personally see the annular eclipse dim the skies during the daytime instead opted to monitor images and livestreams of the event aired during the middle of their local night — an option not available to eclipse enthusiasts just a few decades ago.

Now, worldwide communication and online eclipse-mapping tools, like those from Xavier Jubier of France and retired astrophysicist Fred Espenak (, provide detailed eclipse data for any location on Earth. Additionally, cartographer Michael Zeiler of New Mexico has meticulously created high-quality eclipse maps, while cloudiness statistics over the decades have been gleaned and put into context by Jay Anderson of Canada. (Anderson and I jointly authored the Peterson Field Guide to Weather, which is being published in summer 2021.)

All of these resources are linked on the website for the International Astronomical Union’s Working Group on Solar Eclipses (, which I chair. Additionally, observations of the 75 or so solar eclipses I worked on in the past are posted to the Williams College Eclipse Expeditions website.

Watch: Fly through the Crab Nebula’s delicate heart

These 3D images of the Crab Nebula (M1) show the object as seen from Earth at left, and a simulated rotated view of the nebula from another angle at right.

Thomas Martin, Danny Milisavljevic and Laurent Drissen

The Crab Nebula (M1) is one of the most famous objects in our sky. This cloud of dust and gas marks the gravesite of a massive star that went supernova more than 7,000 years ago.

Although it appears as a smudgy, fuzzy patch of light through smaller scopes, larger instruments reveal a complicated, twisting structure. And a stunning new 3D reconstruction of the remnant’s central regions is now taking our view of this millennia-old object to the next level.

In stunning 3D

Researchers generated the new view using the Spectromètre Imageur à Transformée de Fourier pour l’Etude en Long et en Large de raies d’Emission (SITELLE) instrument on the 3.6-meter Canada France Hawaii Telescope (CFHT) on Mauna Kea. Their reconstruction shows the Crab in exquisite detail from every angle, allowing viewers to zoom in and around the structure. The most striking feature is the remnant’s delicate lattice of gas filaments, which crisscross each other like a honeycomb.

The work was published January 18 in Monthly Notices of the Royal Astronomical Society.

Astronomers still aren’t sure exactly what type of star produced the nebula we see today. And based on their new reconstruction, the team now suggests the Crab’s morphology doesn’t quite match the type of supernova (and thus, progenitor star) that most think created it. The researchers hope that by bringing astronomers up close to — and even inside of — the Crab, they’ll be better able to determine the type of star that exploded to give birth to this amazing object.

This drawing, made in 1844 by William Parsons, the Third Earl of Rosse, shows the Crab Nebula with a long tail. Rosse thought it looked like a horseshoe crab — hence, the Crab Nebula.

William Parsons, Third Earl of Rosse

Evolving view

Although light from the explosive supernova that created the Crab — which sits about 6,300 light-years away — reached Earth in A.D. 1054, the nebula itself wasn’t discovered until 1731. (Twenty-seven years later, it became the first entry in Charles Messier’s list of “not-comets.”)

Its name comes from an 1844 drawing by William Parsons, the Third Earl of Rosse, who studied the nebula through a 36-inch refractor. His depiction included a long “tail” that gave the object the appearance of a horseshoe crab.

Since then, however, our view of the Crab has steadily improved. Case in point: the CFHT that collected the data for this 3D simulation has nearly 16x the light-gathering power of Parsons’ telescope. And even before this, views of the Crab with larger, better instruments — starting with Parsons’ return to the Crab with a 72-inch telescope in 1848 — yielded increasingly accurate images that often left amateurs wondering: “Just where is the crab in the Crab?”

Pluto’s icy “heart” is the distant world’s most recognizable feature. The region, composed of two distinct lobes, is shaped by what looks like a giant impact basin the size of Texas.

The heart’s western lobe, brought into clear focus by the New Horizon’s spacecraft, consists of a 600-mile-wide (1,000 kilometers) ice plain called Sputnik Planitia, which is the largest glacier in the solar system.

Meanwhile, the eastern lobe of Pluto’s heart is a sprawling region of highlands that holds many nitrogen-rich glaciers that extend into the basin.

In this weeks episode of Infinity & Beyond, host Abigail Bollenbach will take you for a quick dive into Pluto’s icy heart. Stay up-to-date on the latest space and astronomy news at And make sure to follow us on Facebook, Instagram, and Twitter.

Space Force sounds like a joke — and that could be a problem for an important military branch

With little else to draw from, people turn to science fiction when thinking about the Space Force.


The U.S. Space Force has a serious role to play in the modern world. Its stated mission is to train and equip personnel to defend U.S. interests in space. Given the increasing military and economic importance of space, the USSF is likely to grow in importance.

But a quick internet search shows that for most people, the Space Force is more a meme than a military branch. It has been the subject of jokes on “Saturday Night Live,” and Netflix was working on a comedy show before the service was officially formed. None other than Captain Kirk himself, actor William Shatner, has weighed in, arguing for the use of Navy ranks over Air Force ranks in the Space Force – after all, he wasn’t Colonel Kirk.

Given this relationship between science fiction and the USSF, few people take it seriously. Modern pop culture depictions of the Space Force as a joke are distracting from the serious responsibilities the USSF is taking on. I am a space policy analyst who has studied the USSF’s relationship with science fiction, and my research shows this is creating a problem for the force.

Many people have compared the U.S. Space Force seal to the insignia from Star Trek.

US Space Force

Sci-fi goes in, jokes come out

There are two things to think about in the relationship between today’s pop culture and the Space Force: how existing sci-fi entertainment warps perceptions of the new military branch, and how those misconceptions lead to a comedic framing of the Space Force in culture today.

Science fiction has long had a strong influence on how people perceive space, and this has carried over to the Space Force. Social media and news coverage of Space Force often include references to “Star Trek,” “Star Wars,” “Guardians of the Galaxy” and “Starship Troopers.” This isn’t surprising. People naturally use analogies to understand new concepts; it’s easier to understand new phenomena in terms of something you already know. Because the Space Force is a new service, people are turning to what they already know about fighting in space. The problem is that science fiction is far from the reality of what missions in space look like today.

A lot of research has explored how fiction can influence people’s thoughts and opinions. One way this can happen is through something called a priming effect, where exposure to an idea in one situation influences how people think about the same idea in an entirely different situation.

People can also become so cognitively and emotionally invested in a fictional story that it begins to subconsciously feel real to them. When this happens, it’s much easier for the fictional ideas to influence their thinking in the real world.

The result of science fiction’s influence, then, is that people have absorbed incorrect ideas about the Space Force – for instance, that it has its own astronauts or is building military bases on the Moon – without questioning the accuracy of these ideas. This leads to the second aspect of USSF’s relationship to pop culture today: Online commentary, media coverage and entertainment have focused on humor at the expense of substantive discussion.

Jokes about “Guardians of the Galaxy” or camouflage in space abound on Twitter and create the impression that the Space Force is inconsequential. The Netflix show “Space Force” has also perpetuated myths that the Space Force is sending astronauts into combat on the Moon. And this joking extends to the highest levels of government, too – even the White House has cracked jokes at the expense of Space Force.

The first mission to space under the jurisdiction of the U.S. Space Force, a communications satellite launch, was not a ‘Star Trek’-style adventure, but it was still important.

U.S. Air Force/Joshua Conti

Problems and potential

Despite the attention all this brings to the Space Force, if people are so deeply influenced by fiction that they find the USSF funny or absurd, it could lead to a disconnect between public expectations and what the Space Force is actually doing, and ultimately, reduce public support.

While missions like surveillance and tracking satellites and space debris may not be as interesting as stories from “Star Wars,” they are fundamental to the global economy and national security.

While the Space Force has fed these perceptions to an extent – for example, using the name Kobayashi Maru from “Star Trek” for one of its software programs – there are ways in which science fiction can be helpful for the new military branch. Science fiction can be inspiring, as it was during the space race of the 1960s and is for space leaders today.

Modern pop culture interest in space can also be used to leverage interest in the Space Force. While it is not engaging in any “Star Trek” sort of exploration, its duties are important and inspiring nonetheless. Without the GPS satellites the Space Force is now in charge of, we wouldn’t be able to get money from an ATM, coordinate financial transactions or monitor such episodes as volcanoes or earthquakes.

The reality portrayed in “Star Trek” is hundreds of years in the future. While the Space Force might be an early step toward that reality; it is merely the first of many. As Gen. Mark Naird in the Netflix comedy series “Space Force” famously intones, “Space is hard.” Though not as glamorous as Hollywood, the hard work defending U.S. national interests in space is important.
Page 184 | Astronomy Magazine (43)

This story was originally published on The Conversation. Read the original here.

Hidden in plain sight: Scouring the notebooks of the Harvard’s ‘human computers’

Williamina Fleming (standing) supervised the women “computers” at Harvard College Observatory. The Harvard Computers spent decades studying the night sky, recording their observations in notebooks and on photographic plates, which citizen scientists are now transcribing.

Harvard College Observatory/Wikimedia Commons)

Citizen Science Salon is a partnership between Discover, our sister publication, and SciStarter.Org.

More than 100 years ago, Harvard astronomer Edward Charles Pickering decided he was going to take a picture of the entire night sky. Or, rather, many thousands of pictures, each capturing a tiny rectangle of the universe as seen through a telescope. Today, these photos survive on hundreds of thousands of glass plates at the Harvard College Observatory, the oldest comprehensive record of the cosmos.
Though it was Pickering’s idea, the actual work of studying these photographs was done by a group of women known as the Harvard Computers. Before the days of silicon and circuits, actual humans performed the laborious mathematical endeavor of physics and astronomy.

“Someone had to go look at every plate covered in thousands of little stars, and they had to look at every star on that plate and catalog it,” says Daina Bouquin, head librarian at the Harvard-Smithsonian Center for Astrophysics. “So this team of women, over the course of a couple of decades, basically analyzed and created the first all-sky catalog.”

History’s ‘hidden figures’

Like the women memorialized in the movie “Hidden Figures,” the Harvard Computers toiled in relative obscurity, yet they produced groundbreaking work fundamental to the field of astronomy. Women like Henrietta Swan Leavitt and Annie Jump Cannon produced some of the first rigorous examinations of the motion and brightness of stars. Today that data is foundational to our understanding of the basic structure of the universe.

“In the late 1800s and early 1900s, astronomy was undergoing a revolution,” Bouquin says. “We were shifting from mapping the sky and what we see and trying to describe it, to trying to understand the physics of the sky. How does it work?”

Now Bouquin is leading an initiative known as Project PHaEDRA. Its goal is to digitize and catalog those decades of work from the Harvard Computers.

But the collection of notebooks is far too extensive for researchers to manage alone. So, the project relies on thousands of volunteers to help comb through decades of invaluable astronomical observations and turn them into something usable for researchers today. Citizen scientists can get involved with Project PHaEDRA from anywhere in the world — all you need is a computer.

Volunteers transcribe notebook pages from astronomers that have been languishing in obscurity for decades and add them to a growing collection of searchable data in a NASA archive. These historic observations are sought after by scientists today, who are continuing the work the computers started.

A cosmic fossil record

While astronomers have learned a lot about how stars, planets, galaxies and more interact and evolve, there’s much that’s still unknown. The cosmos changes slowly, so having a night sky record dating back more than 100 years could help provide data for astronomers to compare and contrast against modern-day observations.

Without such a reference, Bouquin says, “It’s like you didn’t have the fossil record, but you were trying to do paleontology. This gives you that record.”

Currently, the bulk of the Harvard Computers’ work is locked inside thousands of notebooks at the Harvard College Observatory. They contain precise notations and measurements comprising decades of work as the women studied each glass plate in detail and noted the positions, movements and characteristics of the stars it captured. Project PHaEDRA is opening that data up to astronomers for the first time by transcribing the notebooks and converting them into a digital, searchable format.

Citizen scientists working with PHaEDRA are turning the notebooks into a corpus of data that astronomers can reference to see what the night sky looked like over a century ago. That’s important because much of our understanding of the universe comes from watching objects like stars move over time. The further back astronomers can look, the more they can learn.

“Volunteers are the way the whole thing works,” Bouquin says. “We would not be able to do much of anything without the volunteers.”

Astronomer Henrietta Swan Leavitt used this notebook to record stars in the Small Magellanic Cloud, a small satellite galaxy of the Milky Way.

John G. Wolbach Library, Harvard College Observatory

Mapping the stars

The project is currently about halfway through transcribing the collection of thousands of notebooks, Bouquin says. They’ve already uploaded a number of their transcriptions to NASA’s Astrophysics Data System, a massive repository of data from astronomers where scientists can make use of them.

In addition to adding to our knowledge of space, the project is reminding us of the often-overlooked contributions of women in astronomy, Bouquin says. Among other things, Henrietta Swan Leavitt studied variable stars, which change in brightness over time. That work led to the creation of the cosmic distance ladder, a means of measuring things very far away in the cosmos. Her discoveries ultimately helped reveal the age of the universe, and they’re instrumental even today in determining how far away things are.

Another computer, Cecilia Payne-Gaposchkin, studied the spectra of stars — the wavelengths of light they emit. Her work helped show that stars are made primarily of hydrogen and helium. Before that, astronomers thought stars were made of the same elements as Earth.

“Some of them did really, really fantastic work, and all of them contributed to an amazing undertaking,” Bouquin says. “The fact that that got erased is wrong.”

And along with the computers’ observations are bits of historical ephemera that were previously lost to history. Sketches, notes, postcards and more have turned up in the margins of the notebooks, a testament to the very real lives these women lived. Project PHaeDRA volunteers, Bouquin says, have proven adept at picking out these personal touches and bringing a broader perspective to the work of the Harvard Computers.

If not for the work of these modern-day citizen scientists, the valuable efforts of dozens of pioneering women astronomers may have been lost forever. But today, page by page, their hard-won discoveries are returning to the light.

Find Project PHaEDRA, and a variety of other transcription efforts, through Scistarter’s Smithsonian Transcription Center project page. From there, you can navigate to a tutorial on transcribing. Once you’re set up, you can pick from a number of notebooks by different women astronomers and choose one to begin transcribing. The project also shares results through its monthly newsletter.

Exoplanets’ magnetic poles likely wander and flip like Earth’s do

A magnetic field can serve as a protective bubble that keeps a planet’s star from blasting away its atmosphere.


Earth’s magnetic field is vital to maintaining the habitable environment we currently enjoy. This protective bubble deflects solar wind particles and prevents them from eroding the atmosphere.

But Earth’s north magnetic pole is on the move. That motion, combined with several other factors, has led some scientists to wonder whether a magnetic pole reversal — when the north and south magnetic poles switch places — is on the horizon.

When the poles do shift, other changes occur: Earth’s magnetic field loses some 90 percent of its strength during a reversal, potentially exposing the planet to higher amounts of solar and cosmic radiation.

The same, scientists think, is likely true on extrasolar planets as well. That means understanding other planets’ magnetic fields is vital when evaluating whether the worlds we find circling other stars are potentially habitable or not.

Not alone in the cosmos

Little is known about why pole reversals happen in the first place, Jonathan Mound, an associate professor at the University of Leeds, U.K., told Astronomy in 2017.

But while scientists don’t know why reversals occur, they do know Earth is not alone in experiencing them. Magnetic field reversals occur on Jupiter and Saturn as well. Outside the solar system, it is “quite plausible” that exoplanets with Earth-like interiors may experience pole reversals, says Manasvi Lingam, an assistant professor at the Florida Institute of Technology.

On Earth, reversals occur once every several hundred thousand years. That’s pretty frequent in geologic timescales. Jupiter and Saturn’s reversals happen faster still — on the order of centuries. But despite frequent reversals causing a periodic drop in magnetic field strength and an increase in solar radiation, the outcome clearly has not been catastrophic on existing life on Earth.

Still, understanding how frequently exoplanets’ magnetic fields flip or vary is crucial when characterizing their habitability.

Lingam has investigated the influence of varying magnetic fields on exoplanets orbiting red dwarf stars. He says many of the same effects expected to occur on Earth during reversals may also occur on exoplanets when their fields flip. Even when the field isn’t reversing, magnetic poles might wander, and that behavior would impact habitability in subtle ways. But the large number of unknowns makes it difficult to draw definitive conclusions.

“What we can say with some confidence is that suppressing magnetic fields will lead to higher quantities of radiation and potentially higher rates of atmospheric erosion by the stellar wind,” explains Lingam, who explores these questions surrounding habitability in his upcoming book, Life in the Cosmos: From Biosignatures to Technosignatures. “Recent research suggests that neither of these trends is drastic enough to suppress habitability altogether.”

Seeing is believing

The first step to observing reversals is to detect magnetic fields on exoplanets, which in itself is a challenge.

“Of the 4,000 planets [we’ve detected so far], we’ve really only looked for magnetic fields on maybe 15 or less,” says Evgenya Shkolnik, an associate professor of astrophysics at the Arizona State University and an expert on exoplanets and the disks of material that form them.

The exoplanets whose magnetic fields are under scrutiny are hot Jupiters, Shkolnik says. These are exoplanets that are physically similar to Jupiter but much closer to their stars, often orbiting in a matter of days at distances less than that of Mercury from the Sun.

This image shows how a fictitious hot Jupiter — the blue-green dot at far left — orbiting the Sun would appear from Earth during a total solar eclipse.

Evgenya Shkolnik

According to a 2018 study published in Monthly Notices of the Royal Astronomical Society, hot Jupiters are “ideal candidates” to study at radio wavelengths. This offers a direct, unambiguous way to detect exoplanetary magnetic fields because radio emissions are produced when a planet’s magnetic field interacts with stellar wind. Planets orbiting young stars in particular are likely to experience fierce stellar winds frequently and will produce stronger radio emissions.

Astronomers currently know of at least 337 hot Jupiters to date, and have tried repeatedly to observe them at radio wavelengths. But “there have been no unambiguous [radio] detections” yet, Lingam says. Part of the problem, he explains, is that Earth’s ionosphere blocks radio waves from reaching the ground. To see radio waves produced by an exoplanet’s magnetic field, he says, “One would need to deploy large radio telescopes on the Moon or in outer space, both of which are expensive propositions.”

“We have the technology, but not the economics” to pursue exoplanetary magnetic field detections, he says.

But that may soon change. The proposed Farside Array for Radio Science Investigations of the Dark ages and Exoplanets, or FARSIDE telescope, is just one of several projects under consideration by NASA and other organizations for construction. And part of FARSIDE’s goal is right there in the name — it would focus on studying exoplanets and their magnetic fields to evaluate whether these distant worlds have magnetic fields that do indeed make them habitable.

Although researchers admit there’s still a long road ahead to gaining insight into exoplanetary magnetic fields — and thus, habitability — that road is getting shorter day by day.

Page 184 | Astronomy Magazine (2024)


Was it ever possible or is it currently possible for Jupiter to become a star? ›

Jupiter, while more massive than any other planet in our solar system, is still far too underweight to fuse hydrogen into helium. The planet would need to weigh 13 times its current mass to become a brown dwarf, and about 83 to 85 times its mass to become a low-mass star.

Which is better, astronomy magazine or sky & telescope? ›

But, in terms of a 'winner'… well, it has to be Sky & Telescope Magazine. Loads of content, focussing on areas of intense interest to different astronomers each month (moon, planets, deep sky) and then some really comprehensive and interesting stand-alone pieces. What really wins out though is S&T's writing.

What is the dark age in astronomy? ›

The phrase "dark ages of the universe" refers to a phase of the early universe when it was blanketed in darkness. In the early universe, ultraviolet light could not freely travel long distances, as it was absorbed and scattered by dense clouds of neutral hydrogen atoms.

How to find a black hole? ›

Astronomers know there is a black hole when the stars or gas around it are distorted or otherwise changed. These effects show up in a few ways. Astronomers can observe a star accelerating in orbit around an unseen companion, rather than a detectable binary companion star (see video above).

How many human years would it take to get to Jupiter? ›

So, how long does it take to get to Jupiter? Around 600 days if you want to just do a flyby and aren't planning to stick around, or about 2,000 days if you want to actually get into orbit.

Would Earth survive if Jupiter became a star? ›

In the best case scenario Earth's atmosphere will be stripped away and its surface will be turned to a molten, hostile lava. In the worst case, the entire planet will be consumed and vaporized by our once-reliable star. But we won't have to wait 5 billion years to run into stellar trouble.

What happened 300,000 years later and gave us the first radiation light? ›

It took about 300 000 years for the Universe to cool down to a temperature at which atoms can form (about 3000°C). Matter then became neutral, and allowed the light to travel freely: the Universe became transparent. The relic of that 'first light' is the CMB.

What is the dark age called now? ›

The Migration Period was a historical period sometimes called the Dark Ages, Late Antiquity, or the Early Middle Ages. The period lasted from the fall of Rome to about the year 1000, with a brief hiatus during the flowering of the Carolingian court established by Charlemagne.

How old is our universe? ›

Before 1999, astronomers had estimated that the age of the universe was between 7 and 20 billion years. But with advances in technology and the development of new techniques we now know the age of the universe is 13.7 billion years, with an uncertainty of only 200 million years. How did this come to be?

Do wormholes exist? ›

Einstein's theory of general relativity mathematically predicts the existence of wormholes, but none have been discovered to date. A negative mass wormhole might be spotted by the way its gravity affects light that passes by.

What happens when a black hole dies? ›

They simply evaporate away. Black holes, when they are not actively feeding, lose mass and energy as radiation: Hawking radiation. Black holes are black because nothing, not even light, can escape them. Once something crosses its boundary, the event horizon, it's gone for good.

Why are black holes unseeable? ›

Black holes don't emit or reflect light, making them effectively invisible to telescopes. Scientists primarily detect and study them based on how they affect their surroundings: Black holes can be surrounded by rings of gas and dust, called accretion disks, that emit light across many wavelengths, including X-rays.

Could Jupiter have been a star? ›

It may be the biggest planet in our Solar System but it would still need more mass to turn into a second Sun. Jupiter is often called a 'failed star' because, although it is mostly hydrogen like most normal stars, it is not massive enough to commence thermonuclear reactions in its core and thus become a 'real star'.

Was it ever possible or is it currently possible for Jupiter to become a star quizlet? ›

Was it ever possible (or is it currently possible) for Jupiter to become a star? No, it would have to be at least 80 times more massive. Why have astronomers found more Jupiter-sized planets at a distance of 1 AU around other stars than Earth-sized planets?

What stopped Jupiter from becoming a star? ›

"As for why Jupiter failed to become a star--it probably had to do with the accident of the sun grabbing most of the mass early in the formation of the solar system, while in other systems the mass was more equitably distributed; in binary star systems, for example, the masses of the stars are commonly roughly equal.

What would happen if Jupiter was ignited? ›

Fusion would be short lived if it became a brown dwarf, an object midway between star and planet. If it accreted even more mass, just enough to become a true star, it would be a dim red dwarf. Its radiation would barely affect us and it wouldn't look very different to now.


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