Astronomy

Experiments with optical illusions have revealed surprising similarities between human and AI perception

An innovative telescope design has proven successful for daytime skywatching, opening new doors for uninterrupted observation of the cosmos.

How can sunlight reflecting off SpaceX’s Starlink satellites interfere with ground-based operations? This is what a recently submitted study hopes to address as a pair of researchers investigate how Starlink satellites appear brighter—which the researchers also refer to as flaring—to observers on Earth when the Sun is at certain angles, along with discussing past incidents of how this brightness has influenced aerial operations on Earth, as well. This study holds the potential to help spacecraft manufacturers design and develop specific methods to prevent increased brightness levels, which would help alleviate confusion for observers on Earth regarding the source of the brightness and the objects in question.

Here, Universe Today discusses this research with Anthony Mallama of the IAU – Centre for the Protection of Dark and Quiet Skies from Satellite Constellation Interference regarding the motivation behind the study, significant results, potential follow-up studies, importance of studying Starlink satellite brightness, and implications for managing satellite constellations in the future. So, what was the motivation behind this study?

“I study the brightness of Starlink satellites under all circumstances,” Mallama tells Universe Today. “That includes their operational phase at 550 km [342 mi] altitude, when they are rising from the initial orbit around 300 km [186 mi] to operation height, ordinary flares which occur frequently but have small amplitudes and these extreme flares.”

For the study, the researchers conducted a geometrical analysis of the brightness of Starlink satellites based on the Sun’s location and angle in the sky. This comes despite SpaceX taking steps to mitigate reflectivity off Starlink satellites, which only decreases reflectivity when the satellites are directly overhead. The study also discussed how reflectivity from Starlink satellites has affected aerial operations, specifically with commercial airline pilots. Therefore, what were the most significant results from this study?

Mallama tells Universe Today, “This study demonstrated that Starlinks can be exceedingly bright under certain conditions. In one instance they were reported as Unidentified Aerial Phenomenon (UAP) by pilots on two commercial aircraft.”

Regarding potential follow-up studies, Mallama tells Universe Today, “I am characterizing the brightness of other satellite constellations including Amazon’s Kuiper, AST SpaceMobile’s BlueWalker/BlueBirds and Planet’s Pelicans.”

The study mentions how the UAP incidents occurred in 2022 and was recently discussed in Buettner et al (2024) with the pilots’ reporting brightness magnitudes (also called stellar magnitude or apparent magnitude) of -4 to -5. For context, a stellar magnitude of -5 is equivalent to the planet Venus at its brightest, which is known for being observed before sunrise or after sunset periodically throughout the year. The apparent magnitude scale ranges from -30 to 30 with higher numbers corresponding to decreasing brightness.

Buettner et al (2024) was recently presented at the 4th IAA Conference on Space Situational Awareness (ICSSA). That paper discussed how the incident occurred on August 10, 2022, and was observed by five pilots aboard two separate commercial airline flights over the Pacific Ocean, which resulted in two photographs obtained by the pilot’s cell phones. After analyzing a series of simulations and additional data, the researchers determined these UAPs were Starlink satellites launched earlier that day, which was designated as Starlink Group 4-26. Given this incident, what is the importance of studying Starlink brightness/flaring?

Mallama tells Universe Today, “The importance of studying Starlink brightness is that the satellites interfere with astronomical research if they are brighter than magnitude 7. Furthermore, casual sky watchers, such as amateur astronomers and naturalists, are distracted by those brighter than magnitude 6 because they are visible to the unaided eye.”

This study comes as SpaceX’s Starlink constellation continues to grow on a regular basis, with the number of current Starlink satellites in orbit have reached more than 5,600 with almost 6,000 having been launched by SpaceX as of this writing. As noted by both the study and Mallama, sunlight reflectivity off Starlink satellites causes issues with both aerial operations on Earth and astronomical observing, with Mallama also conducting research on satellite constellation brightness for Amazon, AST SpaceMobile, and Planet Labs. Therefore, with the number of satellites in orbit rapidly increasing due to constellations, what implications could this study have on managing satellite constellations in the future?

Mallama tells Universe Today, “One approach to reducing satellite brightness is to reflect sunlight into space rather than allowing it to scatter diffusively toward observers on the ground. That works very well most of the time. However, there are certain Sun-satellite-observer geometries where it fails and observers see a mirror-like reflection of the Sun.” Mallam published a 2023 article with Sky & Telescope discussing how SpaceX’s second-generation of Starlink satellites are fainter than their predecessors.

This diagram and artist illustration demonstrates how sunlight reflects off a Starlink version 1.5 satellite, and was discussed in a 2023 article authored by Anthony Mallama and published in Sky & Telescope. (Credit: SpaceX)

Mallama credits his co-author, Richard Cole, as playing a “crucial role” in this study, noting how Cole “predicted the extreme flares based on his numerical model of Starlink satellite brightness.”

How will sunlight reflectivity off Starlink satellites influence ground operations in the coming years and decades, and what steps can be taken to mitigate this activity? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post Starlinks Can Produce Surprisingly Bright Flares to Pilots appeared first on Universe Today.

It’s been a momentous May for skywatchers around the world. First the big auroral event of May 10-11, next a flaming space rock entering over Spain and Portugal. The inbound object was captured by ground-based cameras and the MeteoSat Third Generation Imager in geostationary orbit.

The incoming meteor dazzled viewers across both countries as it sped across the skies at 160,000 km/hour. Of course, social media came alive with speculation about what was burning up in the atmosphere. Most people thought it was a piece of space rock from an asteroid. European Space Agency members of the Planetary Defence Office immediately began analyzing images and data to figure out the composition of the impactor. Now it seems more likely the chunk of space debris came from a comet. They used other data about the energy released as the fragment flew through the atmosphere to determine the size of the object. It was likely about 1 meter across with a mass of between 500 to 1,000 kg.

On 18 May, the meteor burned up in the night sky over Spain and Portugal – as seen by the fireball camera in Cáceres, Spain, operated by ESA’s Planetary Defence Office

This is pretty small, which makes it hard to spot on the way in. Also, the object approached from the direction of the sky crowded with stars, making it doubly difficult to see as it spun into our planet’s atmosphere. It explains why planetary defense telescopes or observers didn’t detect the meteor.

The Meteor’s Appearance

To most observers, the meteor over Portugal and Spain looked blue-green and very bright. Those colors are created as various elements in the meteor get heated up by friction with our atmosphere. That vaporizes them and we see the “fiery” aspect light up the sky. If it was a piece of a comet, then the colors also indicate the materials it contained. Most comets contain water, carbon dioxide, ammonia, and methane ice. Other comet “stuff” consists of silica dust, carbon, various metals, and organic molecules. The metals, in particular, could show spectacular colors as they heat up and vaporize.

It’s not known which comet supplied the chunk that broke up and vaporized that night. Earth’s orbit crosses the orbit of several different comets. As they travel through space, particularly as they get close to the Sun, comets shed pieces of themselves. That cometary debris stays in the original orbit around the Sun. Occasionally, Earth’s orbit intersects that cometary path. Its particles particles eventually end up in our atmosphere. The best-known path creates the Orionid Meteor Shower and we can thank Comet Halley for that show from late September to mid-November.

Surveys to Detect an Incoming Space Rock

As planetary scientists learn more about the near-Earth environment and its population of asteroids and other space debris, they’ve formed observation groups within NASA and ESA. There’s a network of ground-based observers and facilities that watch the sky each night, looking for incoming impactors. Most of the time, their search is limited to objects larger than the Portugal/Spain object. In addition, satellites such as MeteoSat can pick up these intruders. MeteoSat was launched by ESA to monitor weather conditions and detect lightning strikes. The instrument has four cameras covering Europe, Africa, the Middle East, and parts of South America. Each can capture up to a thousand images per second, allowing the satellite to monitor lightning continuously from space.

ESA’s Planetary Defence Office is in charge of monitoring the positions and approaches of near-Earth objects that could pose a threat to any portion of our planet. It does regular observing campaigns to search for bits of asteroids and comets. NASA operates the Center for Near Earth Object Studies (CNEOS) to do similar searches for possibly dangerous rocks. The Near-Earth objects it’s most concerned about are asteroids and comets with orbits that bring them to within 195 million kilometers of the Sun. Their orbits can move through our planet’s neighborhood. Most of these small bodies are asteroids as small as a few meters wide to nearly 40 kilometers across.

Artist’s concept of the path that a space rock can take that might bring it near Earth. Planetary defense facilities around the planet try to track these objects and warn of their close approach whenever possible. Courtesy: ESA – P.Carril.

The office uses data from observatories around the world—both professional and amateur. Much of this data comes from larger facilities, including Pan-STARRS, the Catalina Sky Survey, and NASA’s NEOWISE mission. In addition, there’s a significant program of planetary radar measurements that contribute data to the NEO observations effort. All of these skywatching campaigns contribute to increased awareness and predictions of near-Earth objects that could pose a threat to our planet.

For More Information

Fireball Witnessed by Weather Satellite

Asteroid Watch

ESA Planetary Defence Office

The post A Weather Satellite Watched a Space Rock Burn Up Above Spain and Portugal appeared first on Universe Today.

One of the main objectives of the James Webb Space Telescope (JWST) is to study the early Universe by using its powerful infrared optics to spot the first galaxies while they were still forming. Using Webb data, a team led by the Cosmic Dawn Center in Denmark pinpointed three galaxies that appear to have been actively forming just 400 to 600 million years after the Big Bang. This places them within the Era of Reionization, when the Universe was permeated by opaque clouds of neutral hydrogen that were slowly heated and ionized by the first stars and galaxies.

This process caused the Universe to become transparent roughly 1 billion years after the Big Bang and (therefore) visible to astronomers today. When the team consulted the data obtained by Webb, they observed that these galaxies were surrounded by an unusual amount of dense gas composed almost entirely of hydrogen and helium, which likely became fuel for further galactic growth. These findings already reveal valuable information about the formation of early galaxies and show how Webb is exceeding its mission objectives.

The research was led by Kasper E. Heintz, a NASA Hubble Fellow and an assistant professor of astrophysics, and his colleagues at the Cosmic Dawn Center (DAWN) at the Niels Bohr Institute. They were joined by researchers from ETH Zurich, the MIT Kavli Institute for Astrophysics and Space Research, the Space Telescope Science Institute (STScI), the Association of Universities for Research in Astronomy (AURA), the European Space Agency (ESA), the NSF’s National Optical-Infrared Astronomy Research Laboratory (NOIRLab), and multiple universities.

Illustration showing the process of Cosmic Reionization, divided into four periods. Credit: NASA

According to models of galaxy formation, the first galaxies are believed to have resulted from the infall of neutral, pristine gas onto the first protogalactic halos. However, the abundance of neutral atomic hydrogen in galaxies has remained unknown due to the difficulty of observing the earliest cosmological periods. “These galaxies are like sparkling islands in a sea of otherwise neutral, opaque gas,” Heintz explained in a NASA press release. “Without Webb, we would not be able to observe these very early galaxies, let alone learn so much about their formation.”

Since the galaxies appeared as little more than red blobs in the Webb images, the team also relied on data obtained by Webb‘s Near Infrared Camera (NIRCam) through the Cosmic Evolution Early Release Science (CEERS) Survey and shared through the Early Release Science (ERS) program. The spectra revealed that light from these galaxies is absorbed by large amounts of neutral hydrogen gas. They then matched the Webb data to models of star formation, which revealed that these galaxies are primarily populated by young stars. Said co-author Darach Watson, a professor at DAWN:

“The gas must be very widespread and cover a very large fraction of the galaxy. This suggests that we are seeing the assembly of neutral hydrogen gas into galaxies. That gas will go on to cool, clump, and form new stars. The fact that we are seeing large gas reservoirs also suggests that the galaxies have not had enough time to form most of their stars yet.”

“We’re moving away from a picture of galaxies as isolated ecosystems,” added Simone Nielsen, a co-author and PhD student at DAWN. “At this stage in the history of the universe, galaxies are all intimately connected to the intergalactic medium with its filaments and structures of pristine gas.”

The timeline from the Big Bang on the right towards the present on the left. In the middle is the Reionization Period where the initial bubbles caused the Cosmic Dawn. Credit: NASA SVS

These results illustrate what is now possible for astronomers, thanks to next-generation telescopes like Webb. Of course, many unanswered questions remain, not the least of which has to do with the distribution of the cold gas in these early galaxies. For instance, how much is located near the center of galaxies versus their outskirts? Also, astronomers are still unsure if this gas is pristine or already populated by heavier elements. As Heintz indicated, “The next step is to build large statistical samples of galaxies and quantify the prevalence and prominence of their features in detail.”

Further Reading: NASA, Science

The post Galaxies in the Early Universe Preferred their Food Cold appeared first on Universe Today.

A set of Australian fossils offers a rare glimpse of the ancient relatives of platypuses and echidnas that lived alongside the dinosaurs 100 million years ago

A set of Australian fossils offers a rare glimpse of the ancient relatives of platypuses and echidnas that lived alongside the dinosaurs 100 million years ago

An exclusive interview with director Brad Peyton on Netflix's new sci-fi film "Atlas."

Here's what it was like to experience the Starmus Festival in Bratislava, where top scientists and musicians united to celebrate Earth with an overarching theme "The future of our home planet".

Sometimes, astronomers get lucky and catch an event they can watch to see how the properties of some of the most massive objects in the universe evolve. That happened in February 2020, when a team of international astronomers led by Dheeraj (DJ) Pasham at MIT found one particular kind of exciting event that helped them track the speed at which a supermassive black hole was spinning for the first time.

Dr. Pasham found AT2020ocn, a bright flash captured by the Zwicky Transient Facility at Palomar Observatory. He thought it might signify a tidal disruption event (TDE). In these extreme events, a black hole rips apart a star. Part of the star’s remnants are flung from the black hole, but part falls into the accretion disk. And how they fall could hold the key to understanding how a black hole is spinning.

How that disk accretes is attributable to a cosmological theory called Lense-Thirring precession, which shows how space-time is warped by powerful gravitational fields—like those around black holes. Lense-Thirring theory predicts that an accretion disk formed after a TDE would “wobble” soon after the event before settling down into a more standard pattern of matter orbiting a black hole. The key would be to catch a TDE event very early after it happened and then watch the resulting “wobbling” over as long of a time span as possible.

Fraser discusses measuring the spin of a black hole.

So catching AT2020ocn was just the first step—then the authors had to monitor it—preferably for months. To do so, they recruited the Neutron Star Interior Composition ExploreR (NICER), an X-ray telescope attached to the ISS. NICER watched the galaxy containing AT2020ocn for 200 days immediately following the bright flash caught by Zwicky. 

They began to notice a pattern. Every 15 days, the amount of X-rays emitted around the black hole peaked sharply, indicating the potential “wobble” they were looking for. Plugging that frequency into equations for the Lense-Thirring theory, along with estimates of the star’s mass and the black hole’s mass, they determined the black hole was spinning at 25% of the speed of light—which is actually relatively slow for a black hole.

A black hole’s rotational speed can increase or decrease depending on its local environment. As it absorbs more material, typically in the form of matter from its accretion disk falling into it, its rotational speed increases. On the other hand, if it collides with another black hole, the overall rotational speed could decrease, as the two black holes’ spins could be opposite. That appears to be what has happened with the black hole that caused the AT2020ocn TDE, given its relatively slow speed compared to other black holes.

Black holes typically spin exceptionally fast, as Fraser discusses in this video.

The findings of this work were recently published in a paper in Nature. They also potentially lay the groundwork for calculating the spin of other supermassive black holes in the galaxy. Dr Pasham believes astronomers could calculate the spins of hundreds of black holes, opening up insights into their formation and life cycle.

But to do that, they will still need a lot of luck. TDEs are relatively rare events, and even when they do happen, there are obvious resource constraints on telescope time. The Vera Rubin Observatory might help, as it will monitor large chunks of the sky, but it’s not scheduled to come online until mid-next year. Until then, those interested in tracking black hole spins might have to rely on serendipity to find a rare event and have the telescope time to monitor it.

Learn More:
MIT – Using wobbling stellar material, astronomers measure the spin of a supermassive black hole for the first time
Pasham et al. – Lense–Thirring precession after a supermassive black hole disrupts a star
UT – Black Holes are Firing Beams of Particles, Changing Targets Over Time
UT – The Milky Way’s Black Hole is Spinning as Fast as it Can

Lead Image:
Artist’s depiction of how the accretion disk around a black hole could wobble in frequency with its spin, and how that wobble might be captured by a sensor near Earth.
Credits: Michal Zajacek & Dheeraj Pasham

The post A New Way to Measure the Rotation of Black Holes appeared first on Universe Today.

The universe is being revealed in exquisite detail with the current generation of large optical telescopes.

Interview with NASA/JPL's systems engineer Bobak Ferdowsi on his "3 Body Problem" cameo.

Black hole singularities defy the laws of physics. New research presents a bold solution to this puzzle: Black holes may actually be a theoretical type of star called a 'gravastar,' filled with universe-expanding dark energy.

It seemed like night, but part of the sky glowed purple.

NASA is actively working to return surface samples from Mars in the next few years, which they hope will help us better understand whether ancient life once existed on the Red Planet’s surface billions of years ago. But what about atmospheric samples? Could these provide scientists with better information pertaining to the history of Mars? This is what a recent study presented at the 55th Lunar and Planetary Science Conference hopes to address as a team of international researchers investigated the significance of returning atmospheric samples from Mars and how these could teach us about the formation and evolution of the Red Planet.

Here, Universe Today discusses this research with the study’s lead author, Dr. Edward Young, who is a professor in the Department of Earth, Planetary, and Space Sciences at UCLA, and study co-author, Dr. Timothy Swindle, who is a Professor Emeritus in the Lunar & Planetary Laboratory at the University of Arizona, regarding the motivation behind the study, how atmospheric samples would be obtained, current or proposed missions, follow-up studies, and whether they think life ever existed on the Red Planet. Therefore, what was the motivation for the study?

Dr. Young tells Universe Today, “We learn a lot about the origin of a planet from its atmosphere as well as its rocks. In particular, isotope ratios of certain elements can constrain the processes leading to the formation of the planet.”

Credit: European Space Agency

Dr. Swindle follows this with, “There are two basic types of motivation. One is that we’re planning on bringing all these rock samples, and we’re going to be interested in knowing how they’ve interacted with the atmosphere, but we can’t figure that out without knowing the composition of the atmosphere in detail. So, we need an atmospheric sample to know what the rocks might have been exchanging elements and isotopes with. But we’d also like to have a sample of the Martian atmosphere to answer some basic questions about processes that have occurred, or are occurring, on Mars. For example, Martian meteorites contain trapped atmospheric noble gases, like krypton and xenon. But it appears that there are at least two different “atmospheric” components in those meteorites.”

For the study, the researchers proposed several benefits of returning a Mars atmospheric sample to Earth, including atmospheric samples being among the NASA Perseverance (Percy) rover sample tubes, gaining insight into potential solar gar within the Martian interior, evolutionary trends in atmospheric compositions, nitrogen cycling, and sources of methane on Mars. For the Percy atmospheric sample, also known as Sample No.1 “Roubion”, the study notes how this sample was obtained after Percy tried to collect a rock core sample but ended up collecting atmospheric gases instead. Additionally, the study proposes the lack of leakage the sample tube will experience while awaiting its return to Earth and the gases present within the sample are ideal for analysis once returned to Earth, as well. But aside from the Percy rover sample, how else could a Martian atmosphere sample be obtained?

“At least two other ideas for collecting a sample of Martian atmosphere have been suggested,” Dr. Swindle tells Universe Today. “One is to fly a spacecraft through the Martian atmosphere, collect a sample as it goes through, then return it to Earth. The other is to have a sample return “cannister” (it doesn’t have to be any bigger than a Perseverance tube) that has valves and a (Martian) air compressor. You could land it on the surface of Mars, open the valve to the atmosphere, turn on the compressor, and get a sample that has hundreds or thousands of times as much Martian atmosphere as a volume that is just sealed without compression, as Perseverance has done, and hopefully will do again.”

Dr. Swindle and Dr. Young both mention the Sample Collection for Investigation of Mars (SCIM) mission, which was proposed in 2002 by a team of NASA and academic researchers with the goal of collecting atmospheric samples at an altitude of 40 kilometers (25 miles) above the Martian surface and return them to Earth for further analysis. While SCIM was selected as a semi-finalist for the 2007 Mars Scout Program, it was unfortunately not selected for further development, and both Dr. Young and Dr. Swindle tell Universe Today there are currently no atmospheric sample missions being planned aside from the Percy rover sample. Therefore, what follow-up studies from this research are currently underway or being planned?

Dr. Swindle and Dr. Young both mention how efforts are being made to collect small quantities of atmospheric gas due to the small size of the sample tubes, with Dr. Swindle telling Universe Today, “A big set of questions right now is how good a sealed Perseverance tube would be at containing an atmospheric sample. How good is the seal? Might the tube spring a leak on a hard landing? Would some molecules in the Martian atmosphere stick to the coatings of the tubes? There’s been some activity on all of these questions, and so far, the answers have all been good – it looks like those Perseverance tubes may do well, even though they weren’t really designed with atmospheric sampling in mind.”

As noted, the purpose of obtaining and returning an atmospheric sample from Mars could help scientists better understand the formation and evolution of the Red Planet. While present-day Mars is a very cold and dry world with an atmosphere that is a fraction of the Earth’s atmosphere, with liquid water being unable to exist on the surface, along with no active volcanism, as well. However, significant evidence obtained from landers, rovers, and orbiters over the last several decades point to a much different Mars billions of years ago after it first formed. This included an active interior that produced a magnetic field that shielded the surface from harmful solar and cosmic radiation, a much thicker atmosphere being replenished from active volcanism, and flowing liquid water, all of which potentially led to the existence of some forms of life on the surface.

However, given Mars’ small size (half of Earth), this means its internal heat cooled off much faster (possibly over millions of years), resulting in volcanism becoming inactive and the dissipation of the magnetic field the interior activity was driving, the latter of which led to harmful solar and cosmic radiation stripping the atmosphere, with the surface liquid water evaporating to space along with it. Therefore, do Dr. Young and Dr. Swindle believe life ever existed on Mars, and will we ever find it?

Dr. Young tells Universe Today, “I really don’t know.  I think microbial life sometime in the past, or even now, is a reasonable hypothesis but we don’t have enough information.”

Dr. Swindle also echoes his uncertainty whether life ever existed on Mars, but elaborates by telling Universe Today, “If there hasn’t, why did life start so early on Earth, but didn’t start on Mars, which had a similar climate at the time. If there has been, how similar is it to life on Earth? Since Earth and Mars are always exchanging rocks because of impacts, is life on Earth related to life on Mars? If it has existed, it will be tough to find. But an atmospheric sample could help. For instance, there seems to be methane in the Martian atmosphere. Most, but not all, of the methane in Earth’s atmosphere is biological, and analyzing the relative ratios of the isotopes of carbon or hydrogen is one of the best ways to figure that out.”

When will we obtain an atmospheric sample of Mars and what will it teach us about the formation and evolution of the Red Planet in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post Could Martian atmospheric samples teach us more about the Red Planet than surface samples? appeared first on Universe Today.

Black holes seem to provide endless fascination to astronomers. This is at least partly due to the extreme physics that takes place in and around them, but sometimes, it might harken back to cultural touchpoints that made them interested in astronomy in the first place. That seems to be the case for the authors of a new paper on the movement of jets coming out of black holes. Dubbing them “Death Star” black holes, researchers used data from the Very Long Baseline Array (VLBA) and the Chandra X-ray Observatory to look at where these black holes fired jets of superheated particles. And over time the found they did something the fiction Death Star could also do – move.

The black holes at the center of the study were supermassive ones at the centers of galaxies. Importantly, they were all surrounded by hot gases that were visible to Chandra’s X-ray sensors. The jets themselves were clearly visible in the data, but there was other important information hiding in it—namely, pockets free from gas, which had been pushed away by the jets.

Each black hole has particle jets in two opposing directions. As those jets push away gas and dust, they open up a pocket in space surrounding the black hole. These are visible in the X-ray data due to a lack of signal from those regions. The researchers hypothesized that the jets should align with the pockets of free space they create.

Black holes have been known to spin for a while – as Fraser discusses.

However, they found that, in at least 6 of the 16 black holes they were studying, the beams had completely changed direction such that the pockets of missing gas no longer aligned with the jets currently emitted from the black hole. In some cases, these changes added up to a 90-degree shift in the direction the jets were facing. What’s even more impressive, they seemed to move on a relatively small time scale, with estimates ranging from 1 to 10 million years. That is a blink of an eye for a black hole over 10 billion years old.

So why is this important? Cosmologists theorize that these disruptive jets put an upper limit on the number of stars that form in the host galaxy of the black holes. They don’t let the gas and dust surrounding them cool down enough to start to form stars and rocky planets. So, while it isn’t clear if the jets of particles themselves are roasting any formed planets like the actual Death Star, it is clear that moving the jets around would cause an even more massive disruption in the star-forming process. In theory, this would mean that galaxies containing these moving jets would have fewer stars, but that is a study for another paper.

Understanding exactly why this is happening might also need to be researched in another paper, but the authors have a few theories. Matter orbiting around the black hole and falling into it could cause the black hole to rotate, causing the jets it emits to move with it. 

How a black hole forms could hold the key to understanding why its jets move over time. Fraser discusses how that happens.

Another explanation is that the gas is moving around the galaxy without being impacted by the beams. In essence, the “cavities” of no gas in a galaxy are remnants of other cosmological forces and have nothing to do with the black hole beams. However, the authors don’t think this is likely because the galaxy mergers that could be one source of causing the “sloshing” happened in the galaxies that had the moving beams and those that didn’t. One would expect the cavities to be present in both types if they were caused by galaxies merging rather than moving jets of particles.

As always, there is more science to do. Thanks to the wonderful world of video streaming, a whole generation of new scientists inspired by the same Death Star could do it.

Learn More:
Chandra – Spotted: ‘Death Star’ Black Holes in Action
Ubertosi et al. – Jet reorientation in central galaxies of clusters and groups: insights from VLBA and Chandra data
UT – It’s Confirmed. M87’s Black Hole is Actually Spinning
UT – The Milky Way’s Black Hole is Spinning as Fast as it Can

Lead Image:
Image from Chandra’s X-Ray and VLBA’s radio data set of a black hole’s jets with “cavities” surrounding it.
Credit: X-ray: NASA/CXC/Univ. of Bologna/F. Ubertosi; Inset Radio: NSF/NRAO/VLBA; Image Processing: NASA/CXC/SAO/N. Wolk

The post Black Holes are Firing Beams of Particles, Changing Targets Over Time appeared first on Universe Today.

Skywatchers who plan to rise early and step outside on June 3 expecting to see a stunning display of visible planets will be quite disappointed, at the very least.

Here's what it was like seeing Ridley Scott's "Alien" on opening day in 1979, in honor of the iconic sci-fi horror film's 45th anniversary.

Two countries—Slovenia and Venezuela—have lost all of their glaciers. It is a grim benchmark showing the progression of climate change

On Episode 112 of This Week In Space, Rod and Tariq talk with Rob Manning, Chief Engineer Emeritus of NASA's Jet Propulsion Laboratory, about Mars exploration and, in particular, Mars Sample Return.