Carolyn Collins Petersen, Author at Universe Today

May 22, 2023May 22, 2023 by Carolyn Collins Petersen

Astronomers Watched a Fast Radio Burst Go Right Through a Star’s Atmosphere

The Green Bank Telescope was able to observe the directional changes of waves from the fast radio burst FRB20190520B as viewed through the lens of a massive star’s atmosphere. Image credit: NSF/GBO/P.Vosteen. — The Green Bank Telescope was able to observe the directional changes of waves from the fast radio burst FRB 20190520B as viewed through the lens of a massive star’s atmosphere. Image credit: NSF/GBO/P.Vosteen.

The universe is filled with things that go flash in the night. That includes fast radio bursts (FRBs). These are brilliant, powerful blips of radio emissions from distant and mysterious sources. Astronomers studying one called FRB 20190520B noticed something fascinating about its signals. They get polarized as they travel outward from the source.

May 16, 2023May 16, 2023 by Carolyn Collins Petersen

Seismic Waves Help Map the Core of Mars for the First Time

An artist’s depiction of the Martian interior and the paths taken by the seismic waves as they traveled through the planet’s core. Image courtesy of NASA/JPL and Nicholas Schmerr.

More than a hundred years after geologists first observed how seismic waves traveled through Earth, they’ve achieved another seismic first. This time, they measured “core-transiting seismic waves” moving through Mars. The InSight lander’s seismic instrument tracked shockwaves generated by an earthquake and an impact event. Their behavior revealed for the first time that Mars very likely has a liquid core. It’s made of a single blob of molten iron alloy.

May 5, 2023May 5, 2023 by Carolyn Collins Petersen

Newborn Star Surrounded By Planet-Forming Disks at Different Angles

This artist's concept is based on Hubble Space Telescope images of gas-and-dust disks around the newborn star TW Hydrae. HST images show shadows sweeping across the disks encircling the system. These shadows are probably from slightly inclined inner disks that block starlight from reaching the outer disk. The disks are slightly inclined to each other due to the gravitational pull of unseen planets warping the disk structure. Credits ARTWORK: NASA, AURA/STScI for ESA, Leah Hustak (STScI)

One of the great questions about our solar system is: what was it like as it formed? We know that a protosolar nebula birthed the Sun and planets. And, we know planets in our solar system have slightly different orbital inclinations, probably due to some interesting dynamics in the birth crèche. Why is that? The answer may be in a slightly weird-looking protoplanetary disk circling the newborn star TW Hydrae.

May 4, 2023May 3, 2023 by Carolyn Collins Petersen

Dark Energy Was Always Present, Everywhere and at Every Time

X-ray (top row) and optical pseudo-color (bottom row) images of three low mass clusters identified in the eFEDS survey data. The highest redshift cluster come from a time when the Universe was approximately 10 billion years younger than today. The cluster galaxies in that case are clearly much redder than the galaxies in the other two clusters. These galaxy clusters were used to determine th extent of dark matter across space and time. Courtesy: eRosita — X-ray (top row) and optical pseudo-color (bottom row) images images of three low mass clusters identified in the eFEDS survey data. The highest redshift cluster come from a time when the Universe was approximately 10 billion years younger than today. The cluster galaxies in that case are clearly much redder than the galaxies in the other two clusters. These galaxy clusters were used to determine th extent of dark matter across space and time. Courtesy: eRosita

The Force is with us, according to cosmologists working to understand a mysterious “something” that’s making the universe expand. Its name? Dark energy. And, it turns out that it’s been present everywhere throughout cosmic history.

May 3, 2023May 3, 2023 by Carolyn Collins Petersen

Astronomers are Starting to Find the Wreckage Left Over from the First Stars in the Universe

Using ESO’s Very Large Telescope (VLT), researchers have found for the first time the fingerprints left by the explosion of the first stars in the Universe. They detected three distant gas clouds whose chemical composition matches what we expect from the first stellar explosions. These findings bring us one step closer to understanding the nature of the first stars that formed after the Big Bang. — This artist’s impression shows a distant gas cloud that contains different chemical elements, illustrated here with schematic representations of various atoms. Using ESO’s Very Large Telescope, astronomers have detected three distant gas clouds whose chemical composition matches what we expect from the explosions of the first stars that appeared in the Universe. These early stars can be studied indirectly by analysing the chemical elements they dispersed into the surrounding environment after they died in supernova explosions. The three distant gas clouds detected in this study are rich in carbon, oxygen, and magnesium, but poor in iron. This is exactly the signature expected from the explosions of the first stars.

The first stars were odd ducks. Nobody’s observed them yet (although astronomers are hopeful JWST might spot them someday) but their ghosts remain. Born more than 13.5 billion years ago, they were very different from most of those we know today. These were massive monsters made mostly of hydrogen and helium. And, when they exploded as supernovae, their “starstuff” got scattered to space. Astronomers have now found the chemical remains of those stars in three distant gas clouds observed by European Southern Observatory’s Very Large Telescope.

May 2, 2023May 2, 2023 by Carolyn Collins Petersen

ESA Can’t Deploy JUICE’s Radar Antenna. It Needs It to Scan Under the Ice at Callisto, Europa, and Ganymede

The Radar for Icy Moons Exploration antenna onboard JUICE after it left Earth. It's still stuck and not yet fully deployed. Courtesy ESA.

In a scene eerily reminiscent of the Galileo spacecraft’s antenna issues, ESA’s Jupiter Icy Moons Explorer (JUICE) is having a problem with an antenna. The 16-meter-long radar Radar for Icy Moons Exploration (RIME) unit is stuck on a tiny pin that’s keeping it from deploying fully.

May 1, 2023May 2, 2023 by Carolyn Collins Petersen

We Can Now See Into the Permanently Shadowed Craters on the Moon

A ShadowCam view of the rim of Shackleton Crater on the Moon, pockmarked with smaller craters. ShadowCam gives a high-resolution view. Courtesy: NASA/KARI/ASU — A ShadowCam view of part of permanently shadowed Shackleton Crater on the Moon, pockmarked with smaller craters. ShadowCam gives a high-resolution view. Courtesy: NASA/KARI/ASU

An instrument called ShadowCam is giving NASA’s planned Artemis missions to the Moon some advanced views of a landing site. It’s mounted to the Danuri Korea Pathfinder Lunar orbiter sent to the Moon last year. Lately, this amazing camera has been sending back some highly detailed images of the lunar north and south pole regions.

April 30, 2023April 30, 2023 by Carolyn Collins Petersen

Be Grateful the Sun Can’t Produce Flares Like This

Artist’s impression of the a massive flare -- called a superflare -- observed on one of the stars in the V1355 Orionis binary star system. The binary companion star is visible in the background on the right. (Credit: NAOJ)

Okay, so we all know that the Sun is heading into solar maximum. That means it’s quite a bit more active, with sunspots, coronal mass ejections, and flares aplenty. But, luckily for us, the Sun isn’t as active as the members of the binary star system V1355 Orionis. One of its stars periodically releases superflares. These are ten times more extensive than the largest solar flare ever recorded on the Sun.

April 30, 2023April 30, 2023 by Carolyn Collins Petersen

A Black Hole Tore a Star to Pieces. The Closest We’ve Ever Seen.

This artist's illustration depicts what astronomers call a "tidal disruption event," or TDE, when an object such as a star wanders too close to a black hole and is destroyed by tidal forces generated from the black hole's intense gravitational forces. (Credit: NASA/CXC/M.Weiss.

We all know that black holes are destructive monsters. Their tremendous gravitational pull sucks in anything that gets in the way. This is particularly true for supermassive black holes in the hearts of galaxies. They can tear apart stars. And, every so often—like once every, 10,000 years, that happens. The star passes too close and the black hole’s gravity shreds it.

April 29, 2023April 29, 2023 by Carolyn Collins Petersen

European Satellite Measures Exactly How Much Ice Has Been Lost from Glaciers

ESA’s Earth Explorer CryoSat mission is dedicated to precise monitoring of changes in the thickness of marine ice floating in the polar oceans and variations in the thickness of the vast ice sheets that blanket Greenland and Antarctica. Its data are being used to measure ice loss in glaciers. Courtesy ESA/AOES Medialab

As global warming heats up our atmosphere a degree at a time, the world’s glaciers are paying the price. In ten years, they’ve shrunk by a total of 2 percent. To look at it another way, collectively the glaciers have lost 2,720 gigatons of ice thanks to warming air.