Deep in the Stone Age, when Neanderthals still lived alongside Homo sapiens, our ancestors might have been agog at a green light in the night sky. Now, that light—C/2022 E3 (ZTF) (more familiarly, the Green Comet)—is back.
The Green Comet’s highly elliptical orbit means it will take a long time for it to swing past Earth again—about 50,000 years, to be specific. And that’s if it repeats its 50,000-year sojourn, which it may not.
Astronomers discovered the comet in March 2022 using the Samuel Oschin robotic telescope at the Zwicky Transient Facility. It passed perihelion (when it is closest to the Sun) on January 12.
Observers in the U.S. can see the comet now through early February, potentially with the naked eye if you’re in a dark viewing area, but your chances will be better using binoculars or a telescope. The best time to see the comet is in the predawn hours, according to NASA.
The comet will make its closest approach to our planet on February 2. The closest approach will take it about 0.29 AU (about 27 million miles) from Earth, according to EarthSky.
G/O Media may get a commission
Up to $100 credit
Samsung Reserve
Reserve the next gen Samsung device All you need to do is sign up with your email and boom: credit for your preorder on a new Samsung device.
Currently, the comet is toward the constellation Boötes and near Hercules, EarthSky reports. (If you’re having trouble finding the comet’s position, you can consult a handy interactive sky chart.) The comet’s location makes it difficult for observers in the Southern Hemisphere to see. From its current location in the night sky, its projected path charts it past Ursa Minor (the Little Dipper), with it passing by Camelopardis at the time of its closest approach.
Comets glow thanks to a combination of their chemical composition and sunlight. Comets that pass near the Sun are illuminated and warmed by its energy, causing molecules on their surface to evaporate and fluoresce. Comet heads glow green when they contain cyanogen or diatomic carbon, according to NASA.
The Green Comet may get as bright as magnitude 5 by the time it’s closest to Earth, according to EarthSky. The lower the number, the brighter the object. The full Moon’s apparent magnitude is about -11, and the faintest objects seen by the Hubble Space Telescope are about magnitude 30, according to Brittanica. The dimmest stars that our naked eye can see are about magnitude 6.
While the comet may reach a brightness of magnitude 5, it’ll probably be helpful to use a pair of binoculars or a telescope if you’re having difficulty spotting the object on a clear night.
The incoming space rock is not the only recent green comet; in 2018, the comet 46P/Wirtanen was bright enough for observers to see with the naked eye, and in 2021, the Comet Leonard glowed green as the ice-ball made its cosmic trajectory.
So keep your eyes up on the clear nights to come. If you see something with a faint green glow, it’s probably our newest cosmic visitor.
More: Mega Comet Arriving From the Oort Cloud Is 85 Miles Wide
A bright green comet will appear in the night skies above Earth, visible for the first time in 50,000 years.
The recently discovered comet, which was given the catchy name C/2022 E3 (ZTF), will soar its closest to the sun on Jan. 12, and will become visible in the Northern Hemisphere in the morning sky.
In Australia, though, it will become visible from early February as it makes its closest pass by Earth on Feb. 2 when it will be a mere 42 million kilometers away.
Comets can be distinguished from stars by their streaking tails of dust and energized particles – which will cause this one to glow bright green. The glow is caused by an envelope that firms around the comet as it passed by the sun and its icy exterior instantly turns into gas.
The comet will soar its closest to the sun on Thursday.Getty Images
Discovered in March last year by astronomers using the Zwicky Transient Facility’s wide-field survey camera in southern California, the comet passes by the far outer reaches of the solar system each time it orbits the sun – which is why it’s taken so long to swing by Earth once more.
It last made its appearance over our blue planet about 50,000 years ago, when a mere two million humans roamed and our ancestors the Neanderthals were not yet extinct.
According to NASA, the comet – though notoriously unpredictable – has been steadily brightening as it approaches the sun, and should be easy to spot with binoculars.
If we’re lucky, it may even become visible to the naked eye in dark skies, NASA said.
The comet C/2017 K2 (PanSTARRS)—or “K2″ for short—was first spotted five years ago, in May 2017 by the Hubble Space Telescope, NASA reports. The agency shared an image of the comet taken on June 20th, 2022, when it was (relatively) near open star cluster IC 4665 and bright star Beta Ophiuchi, near a starry edge of the Milky Way.
This is the first time the K2 comet has made its way to the inner Solar System from the dim and distant Oort cloud, NASA explains. When it was first observed in May 2017, it was the most distant active inbound comet ever discovered—roughly 2.4 billion kilometers from the Sun, between the orbital distances of Uranus and Saturn.
How big is K2?
When the K2 comet first became visible on the Hubble Space Telescope, scientists estimated that it had a nucleus nearly 11 miles in diameter. But according to research from the Canada-France-Hawaii Telescope, the comet’s nucleus is estimated to have a radius between nine and 50 miles. Either way, it’s pretty damn big.
And that’s not counting the size of K2’s tail—the trail of gasses and dust behind the comet—also known as a “coma.” According to early estimates, K2’s tail is anywhere between 81,000 and 500,000 miles across. For some perspective, that’s somewhere between the width of one and six Jupiters.
When will K2 be visible?
Your best chance of seeing the K2 comet will be the night of July 14th, which is when it will make its closest approach to Earth. Even though it’s huge, you’ll likely need at least a small telescope to spot the comet. Look for a fuzzy patch of light (which is the tail).
G/O Media may get a commission
Save Up To 11%
CDCASA Adjustable Dumbbells
Adjustable weight This set of weights comes in 1.25kg(2.75lb), 1.5kg(3.3lb) and 2kg(4.4lb) sizes – four of each weight. It can be assembled into two single dumbbells or a barbell through connecting rods. Multi-functional strength training equipment offers a better training way than any other exercise machine.
If you’d prefer to watch the comet pass Earth from the comfort of your own home, the Virtual Telescope Project will be live-streaming it starting at 6.15 pm on July 14. But don’t worry too much if you miss K2 on the 14th—it should be visible with a telescope until September.
The closest it will get to the Sun will be in December.
Comets have mystified humanity for millennia, but with the James Webb Space Telescope beginning science operations this month, scientists hope to unravel secrets about these icy objects.
In a study led by Heidi Hammel, executive vice president of the Association of Universities for Research in Astronomy and a Webb interdisciplinary scientist, the James Webb Space Telescope‘s powerful infrared instruments will be trained on three comets in the solar system. The goal will be to analyze the comets’ chemical compositions. Because comets are some of the most primitive bodies in the solar system, this information could reveal clues about the solar system’s early life.
“We want to study comets with Webb because of the telescope’s very powerful capabilities in the near- and mid-infrared,” Hammel said in a statement. “What makes those wavelengths of light particularly powerful for cometary studies is that they allow us to study the chemical makeup of this dust and gas that’s come off of the comet’s nucleus and figure out what it is.”
Related:James Webb Space Telescope’s groundbreaking optics explained by NASA
Hammel’s team will observe three comets, each from a different comet family. The first will be a Jupiter-family comet — potentially Comet Borrelly, whose orbit is affected by the gas giant’s gravity. The second will be a main belt comet — likely Comet Read.
The third will be what’s called a “target-of-opportunity comet,” meaning a comet that hasn’t been discovered yet. The researchers hope that this third comet will be spotted by Webb before the beginning of this study and that it will belong to a different comet family than the other two targets. In one possible scenario, the team would be able to study an Oort Cloud comet that might have originated on the outskirts of the solar system. Another possible “opportunity comet” might originate from even farther afield, as did the interstellar objects ‘Oumuamua and C/2019 Q4 (Borisov).
“One of Webb’s strengths is its ability to sense faint objects, and that makes it a great tool to study these very rare and very faint interstellar interlopers,” Hammel said. “If we could glean compositional information about its surface, that might open a whole new field of study.”
These three comets will be some of the first observed by Webb, but they certainly won’t be the last.
“Ultimately, these are just individual examples, but over Webb’s lifetime, we’ll eventually observe many comets, and we’ll have lots of examples from these different classes, and we can compare them all to each other,” Michael Kelley, an associate research scientist at the University of Maryland who is leading the observations of the Jupiter-family and main belt comets, said in the statement. “With time — and in conjunction with all the ground-based data that we’ve had and will continue to obtain — we’ll have a better understanding of where these comets come from.”
The study is part of Cycle 1 of the Guaranteed Time Observations program, which will occur during Webb’s first year of operations.
Follow Stefanie Waldek on Twitter @StefanieWaldek.Follow uson Twitter @Spacedotcom and on Facebook.
Gigantic asteroids have smashed into the Earth before—RIP dinosaurs—and if we’re not watching out for all those errant space rocks, they could crash into our world again, with devastating consequences. That’s why Ed Lu and Danica Remy of the Asteroid Institute started a new project to track as many of them as possible.
Lu, a former NASA astronaut and executive director of the institute, led a team that developed a novel algorithm called THOR, which harnesses massive computing power to compare points of light seen in different images of the night sky, then matches them to piece together an individual asteroid’s path through the solar system. They’ve already discovered 104 asteroids with the system, according to an announcement they released on Tuesday.
While NASA, the European Space Agency, and other organizations have their own ongoing asteroid searches, all of them face the challenge of parsing telescope images with thousands or even 100,000 asteroids in them. Some of those telescopes don’t or can’t take multiple images of the same region on the same night, which makes it hard to tell if the same asteroid is appearing in multiple photos taken at different times. But THOR can make the connection between them.
“What’s magical about THOR is, it realizes that out of all those asteroids, this one in a certain image, and this one in another image four nights later, and this one seven nights later are all the same object and can be put together as the trajectory of a real asteroid,” Lu says. This makes it possible to track the object’s path as it moves, and to determine if it’s on a trajectory bound for Earth. Such a formidable task wouldn’t have been possible with older, slower computers, he adds. “This is showing the importance of computation in going forward in astronomy. What’s driving this is that computation is becoming so powerful and so cheap and ubiquitous.”
Astronomers typically spy asteroids with something called a “tracklet,” a vector measured from multiple images, typically taken within an hour. These often involve an observing pattern with six or more images, which researchers can use to reconstruct the asteroid’s route. But if the data is incomplete—say, because a cloudy night obstructs the telescope’s view—then that asteroid will remain unconfirmed, or at least untrackable. But that’s where THOR, which stands for Tracklet-less Heliocentric Orbit Recovery, comes in, making it possible to ascertain the path of an asteroid that would have otherwise been missed.
While NASA benefits from telescopes and surveys dedicated to spotting potentially hazardous asteroids, other data sets abound. And THOR can use almost any of them. “THOR makes any astronomical data set a data set where you can search for asteroids. That’s one of the coolest things about the algorithm,” says Joachim Moeyens, cocreator of THOR, and an Asteroid Institute fellow and graduate student at the University of Washington. For this initial demonstration, Moeyens, Lu, and their colleagues searched billions of images taken between 2012 and 2019 from telescopes managed by the National Optical Astronomy Observatory, many by a sensitive camera mounted on the Blanco 4-meter telescope in the Chilean Andes.
In 1996, a rock from space was found in southwestern Egypt’s Great Sand Sea. The rock was odd, even by extraterrestrial standards, and a team of researchers studying the rock’s chemistry now propose that it came from a supernova—the brilliant, explosive collapse of a star.
The rock is named Hypatia, after a 4th-century Egyptian mathematician. Based on the pattern of 15 elements in a 3-gram sample of the stone, a team of researchers suspects Hypatia came from well beyond our stellar neighborhood, and emerged from the gas and dusty detritus that followed a distant star’s explosion. Their research is published in the journal Icarus.
The researchers think Hypatia came from a Type Ia supernova; these supernovae occur when white dwarves (the small, dense remnants of stars) consume so much material, often from a neighboring star, that they explode. That distinguishes Typa Ia from Type II supernovae, in which a large star’s core collapses, causing a massive explosion.
“In a sense we could say, we have ‘caught’ a supernova Ia explosion ‘in the act’, because the gas atoms from the explosion were caught in the surrounding dust cloud, which eventually formed Hypatia’s parent body,” said Jan Kramers, a geochemist at the University of Johannesburg, in a university release.
According to the release, the intermingling of gas atoms from the supernova and the dust in which the explosion occurred probably formed a solid rock around the early stages of our own solar system, billions of years ago. On entering and impacting Earth, the parent rock of Hypatia shattered, creating the fragment found in 1996.
G/O Media may get a commission
Save $70
Apple AirPods Max
Experience Next-Level Sound Spatial audio with dynamic head tracking provides theater-like sound that surrounds you
Kramers has been studying Hypatia for nearly a decade. In 2013, argon isotopes from the rock confirmed Hypatia’s extraterrestrial origins, and follow-up studies in 2015 and 2018 indicated that Hypatia was neither from any known comet or meteorite nor from our solar system. Using a proton microprobe, the team inspected the elemental makeup of Hypatia. They found that the elements from the rock indicated it didn’t even come from interstellar dust in our arm of the Milky Way.
Hypatia had too much iron to come from a Type II supernova or a red giant star. Thus, the researchers surmised that the most likely explanation for Hypatia’s unique combination of silicon, sulfur, calcium, titanium, vanadium, chromium, manganese, iron, and nickel was a Type Ia supernova.
Six elements were a lot more present than what models predict for something that came from a Type Ia supernova, though: aluminum, phosphorus, chlorine, potassium, zinc, and copper. Kramers believes Hypatia may have inherited those elemental components from the red giant star that preceded the white dwarf that eventually exploded.
The new research was merely exploratory, and further isotope analysis of the elements in Hypatia will need to happen in order to test the researchers’ hypothesis about the rock’s origins.
More: A Vanished Supernova Will Reappear in 16 Years
Between 2014 and 2016, the European Space Agency’s Rosetta spacecraft orbited and studied a comet hundreds of millions of miles from Earth, collecting data on the space rock’s structure and geology. Now, the ESA is asking the public to study images of the comet and to report differences in its surface features over time.
The object is Comet 67P/Churyumov-Gerasimenko and was first observed in 1969. The comet has an elliptical, 6.5-year orbit. When Rosetta arrived at the object in 2014, it became the first spacecraft to rendezvous with a comet.
As Comet 67P (as it’s known for short) moved through its orbit, the Sun shone on its different sides. That gave Rosetta a hugely illuminating look at the icy rock, views that were captured in numerous images by the onboard OSIRIS camera.
“Given the complexity of the imagery, the human eye is much better at detecting small changes between images than automated algorithms are,” said Sandor Kruk, an astrophysicist at the Max Planck Institute for Extraterrestrial Physics near Munich, Germany, who dreamt up and began the citizen science project.
Using a tool called Rosetta Zoo, members of the public are encouraged to look at side-by-side images of features on Comet 67P that were taken before and after it made its close approach to the Sun. Volunteers can manipulate the images by rotating them and zooming in, and they can indicate the type of feature they think may be exhibited in the image (dust, boulder, or erosive features), and what’s changed about it—whether it newly appeared, disappeared, or simply moved.
“In the past few years, astrophotographers and space enthusiasts have spontaneously identified changes and signs of activity in Rosetta’s images,” said Bruno Merín, the head of the ESA’s ESAC Science Data Center in Spain, in an agency release. “Except for a few cases, though, it has not been possible to link any of these events to surface changes, mostly due to the lack of human eyes sifting through the whole dataset. We definitely need more eyes!”
The volunteer work on the data will be used to produce maps of active areas on the comet’s surface, which scientists will be able to use to make new models of cometary activity. The more eyes there are on these pictures, the more insights can be gleaned about the ancient debris floating through our solar system.
More: Astronomers Spot Some Familiar-Looking Comets Around a Distant Star
Artist’s impression of Comet Bernardinelli-Bernstein.Image: NOIRLab/NSF/AURA/J. da Silva (Spaceengine)
Bernardinelli-Bernstein is officially the largest comet ever discovered, according to updated observations of the inbound object.
Oort Cloud comet C/2014 UN271, also known as Comet Bernardinelli-Bernstein, measures some 85 miles (137 km) in diameter, give or take 10.5 miles (17 km), reports a research team led by astronomer Emmanuel Lellouch of the Paris Observatory. Their new paper on the mega comet has been accepted for publication in Astronomy and Astrophysics Letters, and you can sneak a peak of the preprint at the arXiv.
These latest observations confirm that Comet Bernardinelli-Bernstein is the largest Oort Cloud object ever detected, as it’s nearly twice as big as comet Hale-Bopp (observed in 1997), the nucleus of which measured between 25 and 50 miles (40 and 80 km) wide. It’s also bigger than Comet Sarabat (observed in 1729), which had a nucleus measuring somewhere around 62 miles (100 km) in diameter.
Comet Bernardinelli-Bernstein is currently inbound from the Oort Cloud, a distant region of the solar system known for packing billions and possibly trillions of icy objects. The comet will make its closest approach to Earth in 2031, when it will come to within 11 au of the Sun (1 billion miles), in which 1 au is the average distance from Earth to the Sun. The comet, coming no closer than Saturn, won’t likely be visible to the unaided eye, but astronomers will be keeping a close watch, as it’s turning out to be a rather extraordinary object.
Named after its discoverers, Pedro Bernardinelli and Gary Bernstein from the Dark Energy Survey, the comet is special for several reasons. Astronomers first detected the inbound object when it was still very far away—some 29 au from the Sun (2.7 billion miles). That’s as far out as the orbit of Neptune, but astronomers didn’t appreciate its significance until it came to within 24 au of the Sun (2.2 billion miles), at which time it began to display distinctive cometary activity. Researchers with Las Cumbres Observatory confirmed its cometary nature in June 2021. Its remarkable brightness indicated an object of enormous size, with preliminary estimates pointing to an object between 62 and 230 miles (100 and 370 kilometers) wide.
For the new study, Lellouch and his colleagues used the Atacama Large Millimeter Array (ALMA) in Chile to refine the comet’s size and reflectivity, or albedo. They did so on August 8, 2021, when Bernardinelli-Bernstein was 20 au from the Sun (1.86 billion miles). The team honed in on microwave radiation leaking out from the comet’s nucleus, while taking care to exclude radiation produced by the surrounding cloud of dust.
These thermal emissions pointed to the 85-mile (137 km) diameter, with a lower bound of 75 miles (120 km) and an upper bound of 96 miles (154 km). The large error bar is on account of uncertainties having to do with the object’s shape and reflectivity. Future observations should refine these estimates further.
The estimated albedo of 5.3% now represents the most distant measurement yet of a comet’s reflectivity. With the size of the nucleus now better defined, astronomers will be able to measure how much material the comet will lose during its trip around the Sun.
Bernardinelli-Bernstein is not the 230-mile behemoth suggested by preliminary measurements, but it’s still gigantic. As it nears the Sun, volatiles on its surface, especially ice, will increasingly sublimate, turning directly from solid into gas. This could give the comet a distinctive coma and tail, but we’ll have to wait a few more years to know for sure. We’ll be watching.
More: Astronomers Rally to Stop Starlink and Other Satellite Constellations From Ruining the Sky
University of Cincinnati anthropology student Louis Herzner, bottom, and anthropology professor Kenneth Tankersley use a scanning electron microscope to study iron and silicon-rich microspherules collected at ancient Hopewell sites. Credit: Larry Sandman
The rapid decline of the Hopewell culture about 1,500 years ago might be explained by falling debris from a near-Earth comet that created a devastating explosion over North America, laying waste to forests and Native American villages alike.
Researchers with the University of Cincinnati found evidence of a cosmic airburst at 11 Hopewell archeological sites in three states stretching across the Ohio River Valley. This was home to the Ohio Hopewell, part of a notable Native American culture found across much of the American East.
The comet’s glancing pass rained debris down into the Earth’s atmosphere, creating a fiery explosion. UC archeologists used radiocarbon and typological dating to determine the age of the event.
The airburst affected an area bigger than New Jersey, setting fires across 9,200 square miles between the years A.D. 252 and 383. This coincides with a period when 69 near-Earth comets were observed and documented by Chinese astronomers and witnessed by Native Americans as told through their oral histories.
The study was published in the Nature journal Scientific Reports.
UC archeologists found an unusually high concentration and diversity of meteorites at Hopewell sites compared to other time periods. The meteorite fragments were identified from the telltale concentrations of iridium and platinum they contained. They also found a charcoal layer that suggests the area was exposed to fire and extreme heat.
In his lab, lead author Kenneth Tankersley, a professor of anthropology in UC’s College of Arts and Sciences, held up a container of tiny micrometeorites collected at the sites. A variety of meteorites, including stony meteorites called pallasites, were found at Hopewell sites.
University of Cincinnati anthropology professor Kenneth Tankersley uses a magnet to show how micrometeorites collected at 11 Hopewell sites contain metals such as iron. UC’s analysis found they also contain high levels of platinum and iridium. Credit: Michael Miller
“These micrometeorites have a chemical fingerprint. Cosmic events like asteroids and comet airbursts leave behind high quantities of a rare element known as platinum,” Tankersley said. “The problem is platinum also occurs in volcanic eruptions. So we also look for another rare element found in nonterrestrial events such as meteorite impact craters—iridium. And we found a spike in both, iridium and platinum.”
The Hopewell people collected the meteorites and forged malleable metal from them into flat sheets used in jewelry and musical instruments called pan flutes.
Beyond the physical evidence are cultural clues left behind in the masterworks and oral histories of the Hopewell. A comet-shaped mound was constructed near the epicenter of the airburst at a Hopewell site called the Milford Earthworks.
Various Algonquin and Iroquoian tribes, descendants of the Hopewell, spoke of a calamity that befell the Earth, said Tankersley, who is Native American.
“What’s fascinating is that many different tribes have similar stories of the event,” he said.
“The Miami tell of a horned serpent that flew across the sky and dropped rocks onto the land before plummeting into the river. When you see a comet going through the air, it would look like a large snake,” he said.
“The Shawnee refer to a ‘sky panther’ that had the power to tear down forest. The Ottawa talk of a day when the sun fell from the sky. And when a comet hits the thermosphere, it would have exploded like a nuclear bomb.”
A magnet holds tiny micrometeorites collected from sediment samples taken from an ancient Hopewell site. Researchers say this evidence points to a comet airburst that devastated parts of the Ohio River Valley more than 1,500 years ago. Credit: Michael Miller
And the Wyandot recount a dark cloud that rolled across the sky and was destroyed by a fiery dart, Tankersley said.
“That’s a lot like the description the Russians gave for Tunguska,” he said of a comet airburst documented over Siberia in 1908 that leveled 830 square miles of forest and shattered windows hundreds of miles away.
“Witnesses reported seeing a fireball, a bluish light nearly as bright as the sun, moving across the sky. A flash and sound similar to artillery fire was said to follow it. A powerful shockwave broke windows hundreds of miles away and knocked people off their feet,” according to a story in EarthSky.
UC biology professor and co-author David Lentz said people who survived the airburst and its fires would have gazed upon a devastated landscape.
“It looks like this event was very injurious to agriculture. People didn’t have good ways to store corn for a long period of time. Losing a crop or two would have caused widespread suffering,” Lentz said.
And if the airburst leveled forests like the one in Russia, native people would have lost nut trees such as walnut and hickory that provided a good winter source of food.
“When your corn crop fails, you can usually rely on a tree crop. But if they’re all destroyed, it would have been incredibly disruptive,” Lentz said.
University of Cincinnati anthropology professor Kenneth Tankersley poses in front of a table of ancient stone tools in his office. Tankersley has studied ancient cultures across North America. Credit: Michael Miller
UC’s Advanced Materials Characterization Center conducted scanning electron microscopy and energy dispersive spectrometry of the sediment samples. Inductively coupled plasma mass spectrometry was employed at the University of Georgia’s Center for Applied Isotope Studies. The U.S. Geological Survey provided stable carbon isotope analysis.
Despite what scientists know, there is still much they do not, Lentz said.
“It’s hard to know exactly what happened. We only have a few points of light in the darkness,” he said. “But we have this area of high heat that would have been catastrophic for people in that area and beyond.”
Now researchers are studying pollen trapped in layers of sediment to see how the comet airburst might have changed the botanical landscape of the Ohio River Valley.
Co-author Steven Meyers, a UC geology alumnus, said their discovery might lead to more interest in how cosmic events affected prehistoric people around the world.
“Science is just a progress report,” Meyers said. “It’s not the end. We’re always somewhere in the middle. As time goes on, more things will be found.”
Vast patches of glassy rock in Chilean desert likely created by ancient exploding comet
More information:
Kenneth Barnett Tankersley et al, The Hopewell airburst event, 1699–1567 years ago (252–383 CE), Scientific Reports (2022). DOI: 10.1038/s41598-022-05758-y
Provided by
University of Cincinnati
Citation:
Did comet’s fiery destruction lead to downfall of ancient Hopewell? (2022, February 1)
retrieved 2 February 2022
from https://phys.org/news/2022-02-comet-fiery-destruction-downfall-ancient.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.
Comet Leonard as spotted by Solar Orbiter.Gif: ESA/NASA/NRL/SoloHI/Guillermo Stenborg/Gizmodo
Sun-gazing spacecraft managed by NASA and the European Space Agency are providing unique views of Comet Leonard, an ultrafast chunk of rock, dust, and ice that’s currently traveling through the inner solar system.
Comets often appear from out of the blue, or more precisely, from out of the Oort Cloud. Such is the case with Comet Leonard, which became visible to astronomers in early January of this year.
Leonard is here for a good time, but not a long time. The comet is quickly approaching perihelion, its closest distance to the Sun along its orbital path, causing it to do characteristically cometary things, like glow and grow a gaseous, dusty tail. It’s very faint, but it should be visible when viewed through backyard telescopes or binoculars.
Leonard’s closest approach will happen on January 3, at which time it will zoom to within 56 million miles (90 million miles) of the Sun. The half-mile-wide comet, assuming it doesn’t disintegrate, will then begin a long 35,000-year journey back to the outer realms of the solar system.
Comet Leonard’s journey is being chronicled by astronomers on Earth, but also by telescopes in space, specifically the Solar Terrestrial Relations Observatory-A (STEREO-A), operated by NASA, and Solar Orbiter, a joint project of NASA and ESA. Both are in the business of studying the Sun, but mission controllers recently used the space-based instruments to do some comet spotting.
G/O Media may get a commission
A view of Comet Leonard as captured by NASA’s STEREO-A spacecraft. Gif: NASA/NRL/Karl Battams
STEREO-A, with its onboard SECCHI/HI-2 telescope, captured an animated “difference image” of Leonard. Difference images are “created by subtracting the current frame from the previous frame to highlight differences between them,” according to NASA. In this case, the animated image captured subtle changes in the comet’s appearance, including a lengthening of its tail.
Solar Orbiter, with its onboard Solar Orbiter Heliospheric Imager (SoloHI), captured a video of Leonard using frames collected between December 17 and 19. When SoloHI gathered these images, Leonard was “approximately between the Sun and the spacecraft, with its gas and dust tails pointing towards the spacecraft,” explained ESA in a statement. “Toward the end of the image sequence, our view of both of the tails improves as the viewing angle at which we see the comet increases, and SoloHI gets a side-on view of the comet,” the space agency said.
Watching the video, you can see the Milky Way in the background, while Venus and Mercury perform some timely photobombing in the top right corner (Venus is the brighter of the two objects). Solar Orbiter continued to monitor Leonard until December 22, after which time it disappeared from SoloHI’s field of view.
And now we wait to see if Comet Leonard gets any brighter or if it fails to survive its journey around the Sun. It’s not the most exciting rock to ever visit the inner solar system, but we can’t expect every comet to put on a dazzling light show. Here’s to hoping we get something more dramatic in the coming year.
More: The most exciting things happening in space in 2022.
