Universe Today (Page 18)

How Does the Cosmic Web Drive Galaxy Evolution? Galaxies experience a long strange trip through the cosmic web as they grow and evolve. It turns out that the neighborhoods they spend time in on the journey change their evolution, and that affects their star formation activity and alters their gas content. Astronomer Gregory Rudnick of the University of Kansas has a grant to follow that galactic growth trail and figure out just how the trip alters the evolution of a galaxy. These giant stellar cities are spread throughout the Universe, said Rudnick, explaining that they tend to cluster together into large conglomerations. Hundreds of thousandsRead More →

A Black Hole Has Cleared Out Its Neighbourhood We can’t see them directly, but we know they’re there. Supermassive black holes (SMBHs) likely dwell at the center of every large galaxy. Their overwhelming gravity draws material toward them, where it collects in an accretion disk, waiting its turn to cross the event horizon into oblivion. But in one galaxy, the SMBH has choked on its meal and spit it out, sending material away at high speeds and clearing out the entire neighbourhood. We’ve known there’s something at the heart of large galaxies since the early 1960s when astronomers discovered an unexplained radio source at theRead More →

Dust Ruins Another Way of Measuring Distance in the Universe Astronomers have many ways to measure the distance to galaxies billions of light years away, but most of them rely upon standard candles. These are astrophysical processes that have a brightness we can calibrate, such as Cepheid variable stars or Type Ia supernovae. Of course, all of these standard candles have some inherent variability, so astronomers also look for where our assumptions about them can lead us astray. As a case in point, a recent study in The Astrophysical Journal shows how galactic dust can bias distance observations. The study compares two slightly different waysRead More →

Astronomers See 18 Examples of Stars Getting Torn Apart by Black Holes Black holes have always held a special fascination for me ever since I was a geeky kid looking up at the stars. Their intense forces are the stuff of science fiction and can tear a star to pieces. This process is violent and can send bursts of electromagnetic radiation across the Cosmos. A paper recently published announces the discovery of 18 new tidal events just like this, doubling the number of identified shredded stars.  Black holes are the remains of massive stars that have reached the end of their lives. During the mainRead More →

NASA Continues Testing its New Lunar Spacesuits NASA’s Artemis mission objective is among other things, to get human beings back to the Moon. Much of the attention of late has been focussed on the rocket technology to get the astronauts there but as we progress from Artemis I to Artemis II – which aims to take a crew around the Moon and back before Artemis III lands them on the lunar surface – attention is shifting on the spacesuits the crew will wear. The new suits, built by Axiom Space are designed to provide the mobility and protection required on the surface and now, NASARead More →

Some Young Planets Are Flattened Smarties, not Spheres. One of contemporary astronomy’s most pressing questions concerns planet formation. We can see more deeply than ever into very young solar systems where planets are taking shape in the disks around young stars. But our view is still clouded by all the gas and dust in these young systems. The picture of planet formation just got cloudier with the discovery that some young planets are shaped like flattened candies rather than spheres. There are two main theories for planet formation, and they both start with stars. Stars are born in giant molecular clouds of hydrogen. Due toRead More →

Space Force Chooses its First “Guardian” to go to Space Although the U.S. Space Force is tasked with military operations in regards to space, they’ve never actually sent one of their own into orbit. This week, the agency announced that Col. Nick Hague will launch to the International Space Station in August 2024 to pilot the Crew-9 mission, as part of SpaceX’s ninth crew rotation to the ISS for NASA. He’ll join two NASA astronauts and a cosmonaut on the trip to space and then work as a flight engineer, spending six months on the station doing research and operations activities. “The core of ourRead More →

Astronomers Measure the Mass of the Milky Way by Calculating How Hard it is to Escape If you want to determine your mass, it’s pretty easy. Just step on a scale and look at the number it gives you. That number tells you the gravitational pull of Earth upon you, so if you feel the number is too high, take comfort that Earth just finds you more attractive than others. The same scale could also be used to measure the mass of Earth. If you place a kilogram mass on the scale, the weight it gives is also the weight of Earth in the gravitationalRead More →

NASA’s Juno Probe Makes Another Close Flyby of Io The Juno spacecraft has revealed some fascinating things about Jupiter since it began exploring the system on July 4th, 2016. Not only is it the first robotic mission to study Jupiter up close while orbiting it since the Galileo spacecraft, which studied the gas giant and its satellites from 1995 to 2003. Juno is also the first robotic explorer to look below Jupiter’s dense clouds to investigate the planet’s magnetic field, composition, and structure. The data this has produced is helping scientists address questions about how Jupiter formed and the origins of the Solar System. SinceRead More →

NASA is One Step Closer to Deploying Fission Reactors on the Moon What’s the most important thing you need to live and work on the Moon? Power. For NASA’s upcoming Artemis program, getting power to lunar bases is a top priority. That’s why the agency created its Fission Surface Power Project. The idea is to develop concepts for a small nuclear fission reactor to generate electricity on the lunar surface. The project just finished its initial phase (which began in 2022), which consisted of three $5 million contracts to commercial partners to develop fission reactor designs. NASA selected Lockheed Martin in Bethesda, MD, Westinghouse ofRead More →

The JWST Discovers a Galaxy That Shouldn’t Exist Astronomers working with the JWST found a dwarf galaxy they weren’t looking for. It’s about 98 million years away, has no neighbours, and was in the background of an image of other galaxies. This isolated galaxy shows a lack of star-formation activity, which is very unusual for an isolated dwarf. Most isolated dwarf galaxies form stars, according to a wealth of observations. What’s different about this one? The JWST’s PEARLS (Prime Extragalactic Areas for Reionization and Lensing Science) observing program is aimed at understanding the epoch of galaxy assembly, active galactic nucleus (AGN) growth, and First Light.Read More →

How Could Laser-Driven Lightsails Remain Stable? It’s a long way to the nearest star, which means conventional rockets won’t get us there. The fuel requirements would make our ship prohibitively heavy. So an alternative is to travel light. Literally. Rather than carrying your fuel with you, simply attach your tiny starship to a large reflective sail, and shine a powerful laser at it. The impulse of photons would push the starship to a fraction of light speed. Riding a beam of light, a lightsail mission could reach Proxima Centauri in a couple of decades. But while the idea is simple, the engineering challenges are significant,Read More →

Atmospheres in the TRAPPIST-1 System Should be Long Gone Trappist-1 is a fascinating exoplanetary system. Seven worlds orbiting a red dwarf star just 40 light-years away. All of the worlds are similar to Earth in mass and size, and 3 or 4 of them are potentially habitable. Imagine exploring a system of life-rich worlds within easy traveling distance of each other. It’s a wonderful dream, but as a new study shows it isn’t likely that life exists in the system. It’s more likely the planets are barren and stripped of their atmospheres. The Trappist system has gained a lot of attention since its discovery inRead More →

Astronomers are Getting Really Good at Weighing Baby Supermassive Black Holes In the 1970s, astronomers deduced that the persistent radio source coming from the center of our galaxy was actually a supermassive black hole (SMBH). This black hole, known today as Sagittarius A*, is over 4 million solar masses and is detectable by the radiation it emits in multiple wavelengths. Since then, astronomers have found that SMBHs reside at the center of most massive galaxies, some of which are far more massive than our own! Over time, astronomers observed relationships between the properties of galaxies and the mass of their SMBHs, suggesting that the twoRead More →

Half the Entire Sky, Seen in X-Rays There’s an old trope in science fiction about someone suddenly getting X-ray vision and looking through solid objects. It turns out to be a physical impossibility with our Mark I eyeballs. However, astronomers have found a way around that challenge that lets us study the Universe with X-ray vision. It’s called x-ray astronomy and it’s been around for 60 years. It reveals some of the most energetic and violent events and objects in the cosmos. Those include things like bright quasars, supernova explosions, streams of hot gas between galaxies, and hot, young stars. Recently, astronomers in the eROSITARead More →

A Super-Earth (and Possible Earth-Sized) Exoplanet Found in the Habitable Zone Astronomers have found a new Super-Earth orbiting an M-dwarf (red dwarf) star about 137 light-years away. The planet is named TOI-715b, and it’s about 1.55 Earth’s radius and is inside the star’s habitable zone. There’s also another planetary candidate in the system. It’s Earth-sized, and if it’s confirmed, it will be the smallest habitable zone planet TESS has discovered so far. TOI-715 is an average red dwarf. It’s about one-quarter the mass and about one-quarter the radius of our Sun. TOI-715b is close to the star, and its tight orbit takes only 19 daysRead More →

How Dangerous are Kilonovae? When we look up at the sky on a particularly dark night, there is a sense of timelessness. We might see the flash of a meteor, and occasionally a comet is visible to the naked eye, but the cold and distant stars are unchanging. Or so it seems. There can also be a sense of calm, that despite all the uncertainty of the world, the stars will always watch over us. So it’s hard to imagine that light years away there could be a lurking event that poses an existential threat to humanity. That threat is extremely tiny, but not zero,Read More →

An Astronaut Controls a Robotic Dog From Orbit Swedish astronaut Marcus Wandt took control of a series of robots in Germany while on board the International Space Station, zipping around the Earth at 28,000 kilometers per hour (17,500 mph.) Researchers want to understand how time delays can affect the remote control of robots from an orbiting platform. Future astronauts could control rovers on the Moon’s or Mars’s surface from a spacecraft in orbit. Until now, only wheeled rovers have been part of the tests, but now they have added a dog-like robot called Bert. This robot research session, called ‘Surface Avatar’ follows initial experiments carriedRead More →

Japan Moon Lander Sleeps After Sending Science — Will It Wake Up Again? After a few days of wakefulness, Japan’s SLIM moon lander has gone dormant once more at the start of a 14-day-long lunar night. The upended robot sent back a stream of data and imagery while its solar cells were in position to soak up sunlight, and its handlers hope they can get SLIM to wake up again and resume its work after lunar sunrise in mid-February. The car-sized robot accomplished its primary mission on Jan. 20 (Japan time) when it landed within 100 meters of its target point near Shioli Crater. SLIMRead More →

Asteroid Ryugu Contained Bonus Comet Particles On December 5th, 2020, Japan’s Hayabusa2 mission successfully returned samples it had collected from the Near-Earth Asteroid (NEA) 162173 Ryugu home. Since asteroids are basically leftover material from the formation of the Solar System, analysis of these samples will provide insight into what conditions were like back then. In particular, scientists are interested in determining how organic molecules were delivered throughout the Solar System shortly after its formation (ca. 4.6 billion years ago), possibly offering clues as to how (and where) life emerged. The samples have already provided a wealth of information, including more than 20 amino acids, vitaminRead More →