Universe Today

October 27, 2023October 27, 2023 by Evan Gough

JWST Sees Four Exoplanets in a Single System

This artist’s rendering shows the star HR 8799 and one of its four planets, HR 8799c. It illustrates the system at an early stage of evolution. It also shows the star's dusty disk and rocky inner planets. Credit: Dunlap Institute for Astronomy & Astrophysics

When the JWST activated its penetrating infrared eyes in July 2022, it faced a massive wish-list of targets compiled by an eager international astronomy community. Distant, early galaxies, nascent planets forming in dusty disks, and the end of the Universe’s dark ages and its first light were on the list. But exoplanets were also on the list, and there were thousands of them beckoning to be studied.

But one distant solar system stood out: HR 8799, a system about 133 light-years away.

October 27, 2023October 27, 2023 by Nancy Atkinson

Venus Might Have Had Plate Tectonics Just Like Earth

Radar image of Venus created by the Solar System Visualization project and the Magellan science team at the JPL Multimission Image Processing Laboratory. Credit: NASA/JPL.

Even though Venus is very similar to Earth in many ways, it’s a hell-world with a runaway greenhouse effect. It was assumed this was because it lacked plate tectonics like Earth to sequester carbon inside the planet. A new study suggests that the high nitrogen and argon in its atmosphere are evidence from outgassing when it had plate tectonics billions of years ago. This could mean that Venus was habitable for a long time before something went horribly wrong.

October 27, 2023October 27, 2023 by Evan Gough

What’s the Best Way to Find Planets in the Habitable Zone?

This artist's illustration of Kepler 22-b, an Earth-like planet in the habitable zone of a Sun-like star about 640 light years (166 parsecs) away. Credit: NASA/Ames/JPL-Caltech

Despite the fact that we’ve discovered thousands of them, exoplanets are hard to find. And some types are harder to find than others. Naturally, some of the hardest ones to find are the ones we most want to find. What can we do?

Keep working on it, and that’s what a trio of Chinese scientists are doing.

October 27, 2023October 27, 2023 by Nancy Atkinson

Everything in the Universe Fits in This One Graph. Even the Impossible Stuff

Masses, sizes, and relative densities of objects in our Universe, and more. Credit: Charles H. Lineweaver & Vihan M. Patel, doi: 10.1119/5.0150209.

The Universe has physical constants, such as the force of gravity that define everything. If these constants were any different, our Universe would look quite different. When you consider the types of objects that exist in our Universe – from quarks and bacteria to fleas and superclusters — different forces dominate their existence.

A fascinating new graph plots everything in the known Universe and shows us what’s possible. It also shows what types of objects are prohibited by the laws of physics as we understand them.

October 27, 2023October 27, 2023 by Brian Koberlein

The Milky Way's Black Hole is Spinning as Fast as it Can

Simulation of glowing gas around a spinningblack hole. Credit: Chris White, Princeton University

Pick any object in the Universe, and it is probably spinning. Asteroids tumble end over end, planets and moons rotate on their axes, and even black holes spin. And for everything that spins, there is a maximum rate at which it can rotate. The black hole in our galaxy is spinning at nearly that maximum rate.

October 27, 2023October 27, 2023 by Laurence Tognetti

JWST Confirms the Formation of Heavy Elements in a Kilonova

Image from JWST’s Near-Infrared Camera (NIRCam) instrument displaying GRB 230307A’s kilonova and its former home galaxy, the former of which was found to possess heavy elements. (Credit: NASA, ESA, CSA, STScI, A. Levan (IMAPP, Warw), A. Pagan (STScI))

A recent study published in Nature investigates recent observations from NASA’s James Webb Space Telescope (JWST) and ground-based telescopes of heavy elements within the ejected material of a recent gamma-ray burst (GRB), classified as GRB 230307A, that was likely produced by a kilonova with GRB 230307A being designated as the second-brightest GRB ever detected. The heavy element in question is the chemical element tellurium, which is classified as a metalloid on the periodic table. However, scientists also hypothesize that the element iodine, which is a requirement for most of life on the Earth and classified as a reactive nonmetal, could also exist within the kilonova’s explosion, with both elements residing side-by-side on the periodic table.

October 26, 2023October 26, 2023 by Nancy Atkinson

What a Mess. When the Milky Way and Andromeda Merge, it'll Look Like This

This mess is the billion-year-old aftermath of a double spiral galaxy collision. At the heart of this chaotic interaction, entwined and caught amid the chaos, is a pair of supermassive black holes — the closest such pair ever recorded from Earth. The image was taken by Gemini South, one half of the International Gemini Observatory. Credit: International Gemini Observatory/NOIRLab/NSF/AURA

No need to panic, but the Andromeda Galaxy is barreling towards us. It is due to begin merging with the our Milky Way Galaxy in a few billion years. From an outside observer, that process will very likely look like this new picture captured by the Gemini South Observatory. This is NGC 7727, a peculiar galaxy in the constellation Aquarius, about 90 million light-years away. Two giant spiral galaxies are merging, their gravitational interactions are hurling giant tidal tails of stars into the cosmos.

October 26, 2023October 26, 2023 by Evan Gough

JWST Takes a Detailed Look at Jupiter’s Moon Ganymede

Juno captured this image of Ganymede in July 2022. Now the JWST is taking a look at our Solar System's largest moon. Image Credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill

Nature doesn’t conform to our ideas of neatly-contained categories. Many things in nature blur the lines we try to draw around them. That’s true of Jupiter’s moon Ganymede, the largest moon in the Solar System.

The JWST took a closer look at Ganymede, the moon that’s kind of like a planet, to understand its surface better.

October 26, 2023October 26, 2023 by Nancy Atkinson

Mars Still Has Liquid Rock Near its Core

An artist's depiction of the liquid silicate layer wrapped around the Martian core. Credit: IPGP-CNES.

Why doesn’t Mars have a magnetic field? If it did, the planet would be protected from cosmic radiation and charged particles emitted by our Sun. With a magnetic field, perhaps the Red Planet wouldn’t be the dry, barren world it is today.

It has long been believed that Mars once had a global magnetic field like Earth does, but somehow the iron-core dynamo that generated it must have shut down billions of years ago.

But new seismic data from NASA’s InSight lander might change our understanding of Mar’s interior, as well as alter the view of how Mars evolved and changed over time. InSight’s data revealed the presence of a molten silicate layer overlying Mars’ metallic core. Scientists say this insulating layer is like a blanket that might prevent the core from producing a global magnetic field.

October 26, 2023October 26, 2023 by Evan Gough

An Exo-Neptune Beat the Odds and Kept its Atmosphere

An artist impression of exoplanet LTT9779b orbiting its host star. Credit: Ricardo Ramírez Reyes (Universidad de Chile)

As planet-hunting scientists find more and more planets, they’ve encountered some puzzles. One of them concerns the lack of Neptune-size worlds orbiting close to their stars. Astronomers think that these planets aren’t massive enough to retain their atmospheres in the face of their stars’ powerful radiation, which strips it away.

But at least one of these planets has retained its atmosphere. How?