Tag Archives: Astronomical objects

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NASA’s 2029 DAVINCI Mission To Explore the Atmosphere of Venus

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NASA’s DAVINCI mission to Venus is scheduled for launch in 2029. A new paper details this upcoming journey, a daring mission that could shed new light on the scorching hot planet’s mysterious, and potentially habitable, past.

Upon its arrival at the second planet from the Sun, the probe will plunge through Venus’ atmosphere, ingesting its gases for approximately one hour before landing on the planet’s surface, according to the paper published in The Planetary Science Journal. DAVINCI is designed to act as a flying chemistry lab, and it will use its built-in instruments to analyze Venus’s atmosphere, temperatures, pressure and wind speed, while taking a few photos of its trip through planetary hell.

Short for Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging, DAVINCI is one of three upcoming missions planned for Venus, much to the delight of Venus nerds like myself. And honestly, it’s been a long time coming. NASA’s last mission to Venus, Magellan, arrived at the planet in 1989 and wrapped up science operations in 1994. Since then, NASA hasn’t sent out a specialized Venus mission, although the planet is, like, super hot—literally and figuratively.

Why is NASA sending a mission to Venus?

Understanding Venus helps scientists get a better view of our own planet. Venus and Earth may have started off similarly; the two planets share the same size, mass, and density. But today, Venus boasts temperatures that reach up to 880 degrees Fahrenheit (471 degrees Celsius), with a thick, carbon dioxide-rich atmosphere that traps heat the same way greenhouse gases do on Earth. It also boasts an eerie volcanic landscape. Something may have happened during Venus’s early history to cause it to develop such brutal and inhospitable conditions, and for it to end up so drastically different from Earth.

“Venus’s atmosphere holds the chemical clues to understanding a whole host of aspects of that planet, including what its starting composition was and how its climate has evolved through time,” Paul Byrne, associate professor of Earth and Planetary Science at Washington University in St. Louis, who was not involved in the paper, wrote in an e-mail. “The DAVINCI team in particular is hoping to establish whether Venus really did have oceans of liquid water in its past, and if so when, and why, those oceans were lost.”

How will DAVINCI measure Venus’ atmosphere?

In order to do that, DAVINCI will travel some 38 million miles (61 million kilometers) to Venus. The spacecraft will first perform two flybys of the planet, the first one taking place 6.5 months after launch. During these flybys, the spacecraft will analyze Venus’s clouds and measure the amount of ultraviolet radiation absorbed by the planet’s day side, and also the amount of heat being emitted from the Venusian night side (Venus is not tidally locked, but it has a very slow rotation rate).

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Roughly two years after launch, the DAVINCI probe, known as the Descent Sphere, will descend through Venus’s atmosphere and sample the various gases as it makes its way to the surface. The 3-foot-long (1-meter-long) probe will require an hour to make its way down, experiencing hotter temperatures and higher pressures the further down it goes.

“It turns out that the Venus atmosphere is relatively clement up around 55 km [35 miles], but quickly starts to get hotter and far denser as you approach the surface,” Byrne said. “To say nothing of the sulfuric acid clouds, although thankfully they tend to dissipate once you’ve fallen to an altitude of around 47 km [29 miles].”

The Descent Sphere is equipped with five instruments designed to measure and analyze the chemistry and environment of the Venusian atmosphere; these tools, it’s hoped, will paint a better, more in-depth picture of the layered atmosphere. The probe will begin its interactions with Venus’s upper atmosphere when it reaches an altitude of 75 miles (120 kilometers) and it will eject its heat shield when it’s 42 miles (67 kilometers) from the ground. As soon as it dives below Venus’s thick layer of clouds, around 100,000 feet (30,500 meters) above the surface, the probe will attempt to capture hundreds of images. Venus’s clouds shroud the planet, covering its surface from view, so these images are set to provide some unprecedented views.

Aside from imaging the planet, the Descent Sphere probe will also breathe in some of its atmosphere. “The DAVINCI probe will have a small inlet on the exterior of the pressure vessel (basically a big, metal sphere) through which samples of the atmosphere at different altitudes will be drawn into the spacecraft (or, really, pushed in as the pressure outside the probe starts to dramatically increase over the interior pressure),” Byrne said.

When it lands, the probe should be moving no faster than around 25 miles per hour (40 km/hr). If it survives the atmospheric entry, the probe will—hopefully—land in the Alpha Regio mountains, which are roughly the size of Texas, according to the researchers behind the new paper. Under ideal conditions, the probe will operate for 17 to 18 minutes once it sticks the landing, but it isn’t really required to operate on Venus since all the precious data will have already been collected during its atmospheric plunge.

An illustration of the DAVINCI Descent Sphere falling through the atmosphere of Venus
Screenshot: NASA

Is Venus habitable?

Although Venus today is a less-than-ideal place for life, scientists want to investigate whether or not the planet was ever habitable.

In September 2020, a group of scientists claimed that Venus may have signs of life in its clouds based on a detection of what may be phosphine in the Venusian atmosphere. Phosphine is considered a biosignature gas on Earth. However, the results were largely met with skepticism. But whether or not Venus was ever habitable during its past depends on if the planet once hosted liquid water oceans, or if it simply had a thick, steamy atmosphere.

“The DAVINCI probe will look to answer this question by measuring the ratios of various gases in the atmosphere,” Byrne said. “Those measurements, in turn, will help scientists understand which of their climate and interior evolution models are correct, and thus what the likely planetary history of Venus is—including whether it really was ever habitable.”

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Europe’s Space Agency Needs You to Find the Differences Between These Pictures

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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

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See the ‘Brain Terrain’ of Mars in New Satellite Images

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Recent images captured by the European Space Agency’s Mars Express orbiter reveal large craters in Utopia, the largest known impact basin in the Solar System.

Utopia is about 2,050 miles wide—roughly the distance from London, England to Alexandria, Egypt. These striking geological features are located in Utopia Planitia, a massive lava plain that is now rich with ice that sits on and beneath its surface. (Utopia Planitia is also where China’s Zhurong rover landed nearly one year ago; the rover has spent its time driving around the vast plain and taking selfies).

Zipping above the Martian atmosphere, the orbiter and its High Resolution Stereo Camera captured two craters on the lava plain. The topographical image, below, was created from data collected by the orbiter in July but only recently produced and shared with the public in an ESA release. On either side of the craters are flat surfaces called mantled deposits, which are layers of dust and ice that probably originated from ancient Martian snows, when the planet’s rotational axis had a more severe tilt than it does today.

One of the craters (toward the bottom of the image) has ‘brain terrain’ inside it, so-named for its resemblance to the ridges of the human brain. If you look closely, you can make out the undulating ridges within the crater.

A cropped view of the brain terrain.
Image: ESA/DLR/FU Berlin

There are several ideas about brain terrain’s origins; one leading theory is that the terrain comes from buried water that sublimates, weakening the Martian surface and giving it a rippled look. It’s hard to deduce how the geological feature forms from Martian orbit, but some brain terrain on Earth may offer clues.

Adjacent to the craters in the Mars Express images is a swath of darker material; ESA researchers believe that icy ground cracked in places, which allowed dust blowing around the planet to settle in the cracks.

For all its burnt reds and hazy yellows—all too reminiscent of a terrestrial desert—Mars is a frigid (albeit dynamic!) wasteland of carbon dioxide, dust, and ice. Observing from space can only offer so many insights; the more robots we land on the planet, the more we’ll understand the geological and hydrological process of the Red Planet.

The Perseverance rover has noticed some interesting details about how Jezero Crater took shape over millions of years, and the planned ExoMars Rosalind Franklin rover—still alive but barely breathing—is supposed to dig into the Martian soil, perhaps revealing insights even InSight couldn’t deliver.

Brain terrain remains an intriguing aspect of the Martian surface, and with more boots—erm, wheels—on the ground we may figure out exactly what causes it.

More: NASA and ESA Change Plans for Ambitious Mars Sample Return Mission

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Parker Solar Probe Image Shows Venus Glowing Like an ‘Iron Pulled From a Forge’

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Images taken during Parker Solar Probe’s fourth flyby of Venus were stitched together to create this animation.
Gif: NASA/APL/NRL

NASA’s Parker Solar Probe has taken unprecedented visible-light images of Venus’s nightside, revealing surface features that would otherwise be obscured by clouds.

The new views were captured when the spacecraft made its fourth pass of Venus in 2021. Parker is using the planet’s gravity to get closer to its primary target, the Sun, but mission specialists have found a surprising use for the probe as a tool for studying Venus.

The onboard Wide-field Imager for Parker Solar Probe, or WISPR, imaged the entire nightside of Venus in wavelengths of the visible spectrum and near-infrared, according to a NASA release. The fun thing about all of this is that WISPR is designed to capture images of the solar corona—the area of plasma around the Sun—but the Parker team has learned, much to their surprise, that it’s also capable of gazing through Venus’s thick atmosphere.

Dark areas are cooler, high elevation features, while lighter areas are warmer, lower elevation surface features.
Image: NASA/APL/NRL

“Venus is the third brightest thing in the sky, but until recently we have not had much information on what the surface looked like because our view of it is blocked by a thick atmosphere,” Brian Wood, a research physicist with the U.S. Naval Research Laboratory, said in the statement. “Now, we finally are seeing the surface in visible wavelengths for the first time from space.”

The images are allowing scientists to discern surface features such as continental expanses, plains, and plateaus. The new data will provide valuable information about the planet’s geology and history, NASA said.

The longest wavelengths of visible light can penetrate Venus’s clouds, which WISPR detects as a faint glow on the planet’s nightside (when the wavelengths aren’t crowded out by the Sun). Light areas in the images are warmer, while dark areas are cooler. The “surface of Venus, even on the nightside, is about 860 degrees,” said Wood. “It’s so hot that the rocky surface of Venus is visibly glowing, like a piece of iron pulled from a forge.”

That WISPR was capable of this feat became apparent during Parker’s third flyby of Venus in July 2020. The partial view of Venus took the team by surprise, so they ramped things up for the next encounter. Parker’s fourth trip around Venus lined up perfectly such that the probe was able to capture the planet’s entire nightside as it zipped past.

The team identified surface features by comparing the new images to pre-existing topographical maps created with radar, including radar views captured during NASA’s Magellan mission of the 1990s. Features visible in the new images include the continental region Aphrodite Terra, the Tellus Regio plateau, and the Aino Planitia plains. The team even spotted a halo around Venus, the result of oxygen atoms hitting the atmosphere.

The new data will be of interest to other scientists, as it could be used to detect minerals on the surface, since different minerals glow at specific wavelengths. It could also shed new light on the history of the planet and how volcanic activity may have contributed to its evolution and thick atmosphere.

More: In a Scientific First, Astronomers Capture a Complete View of Venus’s Orbital Dust Ring

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Mega Comet Arriving From the Oort Cloud Is 85 Miles Wide

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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

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Astrophysicists Found 1,000 Magnetic Milky Way ‘Strands’

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A new mosaic image taken by the MeerKAT radio telescope in South Africa has revealed nearly 1,000 multi-light-year-long electron strands at the center of the Milky Way. The strands are huge streaks of cosmic ray particles; though they were discovered nearly 40 years ago, researchers never knew there were so many.

The MeerKAT array is just part of the massive Square Kilometer Array, which studies galactic evolution and cosmic magnetism, among other things. The recent image—comprising 20 separate observations in the radio wavelengths and totaling 144 hours—revealed 10 times more filaments than had been known previously. The team’s research is currently hosted on the preprint server arXiv and has been accepted for publication in the Astrophysical Journal Letters.

“We have studied individual filaments for a long time with a myopic view,” said Farhad Yusuf-Zadeh, an astrophysicist at Northwestern University and the paper’s lead author, in a university release. “Now, we finally see the big picture — a panoramic view filled with an abundance of filaments.”

Armed with the new image of the strands, a group of astrophysicists recently conducted population studies of the huge one-dimensional structures, which stretch up to 150 light-years long and are composed of electrons that are interacting with a magnetic field. The structures appear in pairs or in small groups, making them look like massive scratch marks stretched across the center of the galaxy.

The 64-dish MeerKAT telescope array in South Africa in 2018.
Photo: MUJAHID SAFODIEN / AFP (Getty Images)

The origin of the filaments remains unknown, but seeing a bunch of the structures at once has helped the team narrow down their list of suspects. Variations in the radiation emitted by the filaments have led the team to conclude that the strands are likely related to outbursts from the supermassive black hole at the Milky Way’s center, Sagittarius A*, rather than the product of supernovae, or the explosive deaths of stars.

Yusuf-Zadeh told Gizmodo in an email that activity from Sagittarius A* could have shaped the cosmic rays into magnetized tails. The situation could be “similar to cometary tails when solar winds interact with a comet or a planet,” he said.

Going forward, the team plans to expand the region they observe, in hopes of finding more information about the filaments and their origin. In concert with imagery from other observatories, like the upcoming Rubin Observatory in Chile, the findings could help explain what sort of antics cause these phenomena at the heart of galaxies.

More: The World’s Largest Digital Camera Is Almost Ready to Look Back in Time

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How to Spot Leonard, the Brightest Comet of the Year

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A stunning view of comet Leonard, as seen in the skies above the Eastern Sierra mountains of California. Dan Bartlett created the picture from 62 different images captured by a mid-sized telescope.
Image: Dan Bartlett

The time has arrived for skywatchers to look up and catch a glimpse of comet Leonard. Here’s how you can find this gigantic ball of ice and dust.

Senior research specialist Greg J. Leonard discovered the comet that now bears his name on January 3, from the Mount Lemmon Observatory in Arizona. Comet Leonard (or more formally, C/2021 A1) is en route to the inner solar system, and, as is customary of inbound comets, it’s increasingly shedding its surface materials into space. Leonard’s closest approach to the Sun—its perihelion—will happen on January 3, 2022, after which time it will begin its long journey to the outer solar system.

The window for viewing Leonard without super-sophisticated astronomical equipment is now open. Spotting the comet with binoculars and amateur telescopes should be relatively easy. Leonard might even be visible to the unaided eye, but cometary behavior and brightness are difficult to predict.

“Right now, Leonard sports a small but lush dust tail,” according to Sky & Telescope. “If its dust production rate climbs in the coming weeks as the comet approaches the Sun and becomes more active, two special circumstances—an orbital plane crossing and a high phase angle—may boost its brightness above predictions.”

Leonard’s closest approach to Earth will happen on December 12, at which time it will be 21 million miles (34 million km) away. At perihelion, Leonard will be 0.6151 AU from the Sun, or 57 million miles (92 million km).

The object should appear as a very faint fuzzy star. The good news is that Arcturus—the brightest star in the northern constellation of Boötes and the fourth-brightest star in the night sky—can be used as a reference point. Again, don’t assume that you’ll be able to spot Leonard with your eyes alone, as you’ll likely need some optical aid.

Skywatchers in the Northern Hemisphere should currently look for Leonard high in the predawn sky while facing east. As Space.com reports, Monday December 6 will offer an excellent opportunity to view Leonard (local weather conditions permitting):

You will immediately notice the brilliant orange-yellow star, Arcturus in the constellation of Boötes the Herdsman. Now, with binoculars, scan that part of the sky about 5 degrees to the left of Arcturus and you should see Comet Leonard. The comet’s dust tail, which started to lengthen noticeably during early November, should be pointing almost straight up.

Leonard “will just be about half the width of a clenched fist to the left” of Arcturus, Ed Krupp, an astronomer and the director of the Griffith Observatory in Los Angeles, told NPR.

Later this month, from around December 14 to 16, the comet will be visible after sunset, appearing very low along the southwest horizon. The comet will disappear from view after Christmas, but only for viewers in the Northern Hemisphere. Skywatchers in the Southern Hemisphere can catch a glimpse of Leonard starting in mid-December and into early January, as EarthSky reports.

At speeds reaching 158,084 miles per hour (254,412 km/h) relative to Earth, Leonard is considered an ultrafast comet. That said, Leonard will still appear stationary in the sky due to the distances involved, but its speed means its position in the sky will change daily. EarthSky has provided some handy charts that you can use to track the comet’s position over the coming days and weeks.

Sky & Telescope says it will take Leonard 35,000 years to reach its farthest distance from the Sun, which means a full year on Leonard lasts for around 70,000 years. All the more reason to make the effort to view this comet.

More: Close-Up View of Comet NEOWISE Shows It Survived Close Encounter With Sun.

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Astronomers Spot Two Supermassive Black Holes on a Collision Course

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The galaxy NGC 7727 (right) and a zoomed-in view (left) showing the two galactic nuclei that contain the supermassive black holes.

Through a standard telescope, the nearby galaxy NGC 7727 looks like a gossamer tumbleweed drifting in the night sky. But within it are two supermassive black holes beginning a dance that will end with their violent merger. As a team of astronomers recently found, these objects are closer to Earth than any other supermassive pair.

One of the black holes is 6.3 million times the mass of the Sun, while the other is a whopping 154 million solar masses. The duo is located 89 million light-years from Earth in the constellation Aquarius. The team determined the objects’ masses by studying how their gravitational pulls affected stars in their vicinity.

Supermassive black holes lurk at the center of galaxies—our own galaxy hosts Sagittarius A*, a roughly 4 million solar mass black hole 26,000 light-years from Earth. When two galaxies merge, the black holes end up circling one another and eventually merging themselves. These black hole mergers are some of the most violent astrophysical phenomena in the universe, and they generate the gravitational waves famously predicted by Einstein and first observed by the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 2015.

The nearness of the NGC 7727 pair blew the previous record-holding pair out of the interstellar water—that pair was 470 million light-years from us. The team’s research is set to publish in Astronomy & Astrophysics.

“Once the black holes get much closer to each other, they will become gravitationally bound and orbit each other,” said lead study author Karina Voggel in an email to Gizmodo. “This is in theory observable, but this stage in black hole evolution lasts only a short time over a cosmic timescale, and so far we have not observed it.” Voggel, an astronomer at the University of Strasbourg in France, said that unknown galaxy merger relics like it could increase the total number of supermassive black holes by up to 30%.

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“Currently, LIGO can detect gravitational wave events from black holes that merge that have a couple times the mass of our Sun,” Voggel added. “When the LISA space mission will come online in a few years, we will be able to also detect the gravitational wave events from the merging of such supermassive black holes.”

While the galaxy is visible through a normal telescope, when seen through the European Southern Observatory’s Very Large Telescope one can make out little orbs of light within the galaxy that mark where the black holes are. (The gravitational pull of black holes is so strong that light famously cannot escape from them, but the objects are often surrounded by superheated plasma that glows brightly.)

“The small separation and velocity of the two black holes indicate that they will merge into one monster black hole,” said study author Holger Baumgardt, an astrophysicist at the University of Queensland, Australia, in an ESO release.

Black hole astronomy is about to get a boost, as the ESO’s Very Large Telescope is set to be succeeded by the Extremely Large Telescope by the end of the decade. The new telescope will sit high in Chile’s Atacama Desert, an attractive spot for astronomers for its altitude, clear skies, and lack of light pollution.

“This detection of a supermassive black hole pair is just the beginning,” said co-author Steffen Mieske, an astronomer at ESO in Chile, in the same release. “We will be able to make detections like this considerably further than currently possible. ESO’s ELT will be integral to understanding these objects.”

Modern gravitational wave observatories are able to detect the ripples in space-time created by collisions of black holes as well as black holes and neutron stars. But we probably won’t get a chance to see this pair finally embrace, since the researchers’ best guess for their merger date is simply “within the next 250 million years,” according to Baumgardt.

This article has been updated to include comments from Karina Voggel.

More: Physicists See Light Echoing From Behind a Black Hole for the First Time

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Two New Ancient Galaxies Have Been Discovered

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Artist’s impression of an ancient galaxy.
Image: University of Copenhagen/NASA

The presence of two previously undetected galaxies some 29 billion light years away suggests our understanding of the early universe is upsettingly deficient.

Introducing REBELS-12-2 and REBELS-29-2—two galaxies that, until very recently, we didn’t even know existed. The light from these galaxies took 13 billion years to get here, as these objects formed shortly after the Big Bang. The ongoing expansion of the universe places these ancient galaxies at roughly 29 billion light years from Earth.

New research published in Nature suggests REBELS-12-2 and REBELS-29-2 had escaped detection up until this point because our view of these galaxies is clouded by thick layers of cosmic dust. The Hubble Space Telescope, as mighty as it is, could not peer through the celestial haze. It took the ultra-sensitive ALMA radio telescope in Chile to spot the galaxies, in what turned out to be a fortuitous accident.

“We were looking at a sample of very distant galaxies, which we already knew existed from the Hubble Space Telescope. And then we noticed that two of them had a neighbor that we didn’t expect to be there at all,” Pascal Oesch, an astronomer from the Cosmic Dawn Center at the Niels Bohr Institute in Copenhagen, explained in a statement. “As both of these neighboring galaxies are surrounded by dust, some of their light is blocked, making them invisible to Hubble.”

Oesch is an expert at finding some of universe’s farthest galaxies. Back in 2016, he and his colleagues detected the 13.4 billion-year-old GN-z11 galaxy, setting a cosmic distance record. GN-z11 formed a mere 400 million years after the Big Bang.

The ALMA radio telescope made the discovery possible.
Image: University of Copenhagen/NASA

The new paper describes how ALMA and the new observing technique developed by Oesch and his colleagues might be able to spot similarly obscured ancient galaxies. And there’s apparently many more awaiting discovery. The astronomers compared the two newly detected galaxies to previously known galactic sources in the early universe, leading them to suspect that “up to one in five of the earliest galaxies may have been missing from our map of the heavens,” Oesch said.

To which he added: “Before we can start to understand when and how galaxies formed in the Universe, we first need a proper accounting.” Indeed, the new paper asserts that more ancient galaxies existed in the early universe than previously believed. This is significant because the earliest galaxies formed the building blocks of subsequent galaxies. So until we have a “proper accounting,” as Oesch put it, astronomers could be working with a deficient or otherwise inaccurate model of the early universe.

The task now will be to find these missing galaxies, and thankfully an upcoming instrument promises to make this job considerably easier: the Webb Space Telescope. This next-gen observatory, said Oesch, “will be much more sensitive than Hubble and able to investigate longer wavelengths, which ought to allow us to see these hidden galaxies with ease.”

The new paper is thus testable, as observations made by Webb are likely to confirm, negate, or further refine the predictions made by the researchers. The space telescope is scheduled to launch from French Guiana on Wednesday December 22 7:20 a.m. ET (4:30 a.m. PT).

More: Webb Telescope Not Damaged Following Mounting Incident, NASA Says.

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8 Epic Photos of Asteroids Seen Up Close

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Asteroids come in all shapes and sizes; some are large enough to earn the title of dwarf planet, while others are about ostrich-sized. These wandering rocks are incredibly important objects for scientists seeking information about the formation of the solar system and even life on Earth. Some meteorites (the space rocks that fall to Earth) contain amino acids, and plenty of asteroids contain evidence that they once carried water. The history of life on Earth could be chalked up to a couple lucky fallen rocks, in theory.

We’ve visited only a few asteroids to date, but NASA is working on changing that. The recently launched Lucy spacecraft is set to explore Jupiter’s Trojan asteroids, a mission that will bring us a whole new understanding of these strange objects. But until Lucy gets to its first targets, we’ll have to keep ourselves busy with the space rocks we’ve already seen up close.

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