Universe Today

February 20, 2024February 20, 2024 by Alan Boyle

Scientists Track How a Giant Wave Moved Through Our Galactic Backyard

Illustration: Radcliffe Wave model — This illustration shows how the Radcliffe Wave moves through the backyard of our sun (shown as a yellow dot). The white line represents the wave's current shape and motion. Magenta and green lines show how the wave is expected to move over time. (Credit: Ralf Konietzka, Alyssa Goodman and WorldWide Telescope via CfA)

Astronomers say there’s a wave rippling through our galactic neighborhood that’s playing a part in the birth and death of stars — and perhaps in Earth’s history as well.

The cosmic ripple, known as the Radcliffe Wave, was identified in astronomical data four years ago — but in a follow-up study published today by the journal Nature, a research team lays out fresh evidence that the wave is actually waving, like the wave that fans in a sports stadium create by taking turns standing up and sitting down.

“Similar to how fans in a stadium are being pulled back to their seats by the Earth’s gravity, the Radcliffe Wave oscillates due to the gravity of the Milky Way,” study lead author Ralf Konietzka, a researcher at Harvard and the Harvard-Smithsonian Center for Astrophysics, or CfA, said in a news release.

February 20, 2024February 20, 2024 by Evan Gough

JWST Sees a Milky Way-Like Galaxy Coming Together in the Early Universe

The ancient Firefly Sparkle galaxy is precursor to galaxies like the Milky Way. The JWST found ten separate clusters in the galaxy that show how the galaxy is growing through mergers. Image Credit: Mowla et al. 2024.

The gigantic galaxies we see in the Universe today, including our own Milky Way galaxy, started out far smaller. Mergers throughout the Universe’s 13.7 billion years gradually assembled today’s massive galaxies. But they may have begun as mere star clusters.

In an effort to understand the earliest galaxies, the JWST has examined their ancient light for clues as to how they became so massive.

February 20, 2024February 21, 2024 by Matt Williams

The Brightest Object Ever Seen in the Universe

This artist’s impression shows the record-breaking quasar J059-4351, the bright core of a distant galaxy that is powered by a supermassive black hole. The light comes from gas and dust that's heated up before it's drawn into the black hole. Credit: ESO/M. Kornmesser

It’s an exciting time in astronomy today, where records are being broken and reset regularly. We are barely two months into 2024, and already new records have been set for the farthest black hole yet observed, the brightest supernova, and the highest-energy gamma rays from our Sun. Most recently, an international team of astronomers using the ESO’s Very Large Telescope in Chile reportedly saw the brightest object ever observed in the Universe: a quasar (J0529-4351) located about 12 billion light years away that has the fastest-growing supermassive black hole (SMBH) at its center.

February 19, 2024February 19, 2024 by Nancy Atkinson

Japan's New H3 Rocket Successfully Blasts Off

The launch of Japan's H3 rocket on February 17, 2024. Credit: JAXA.

Japan successfully tested its new flagship H3 rocket after an earlier version failed last year. The rocket lifted off from the Tanegashima Space Center on Saturday, February 17, reaching an orbital altitude of about 670 kilometers (420 miles). It deployed a set of micro-satellites and a dummy satellite designed to simulate a realistic payload.

With the successful launch of the H3, Japan will begin transitioning away from the previous H-2A rocket which has been in service since 2001 and is set to be retired after two more launches. Several upcoming missions depend on the H3, so this successful test was vital.

February 19, 2024February 19, 2024 by Brian Koberlein

Gravastars are an Alternative Theory to Black Holes. Here's What They'd Look Like

Artist view of a black hole in the middle of solar system. Credit: Petr Kratochvil/PublicDomainPictures CC0

One of the central predictions of general relativity is that in the end, gravity wins. Stars will fuse hydrogen into new elements to fight gravity and can oppose it for a time. Electrons and neutrons exert pressure to counter gravity, but their stability against that constant pull limits the amount of mass a white dwarf or neutron star can have. All of this can be countered by gathering more mass together. Beyond about 3 solar masses, give or take, gravity will overpower all other forces and collapse the mass into a black hole.

February 19, 2024February 19, 2024 by David Dickinson

European Satellite ERS-2 to Reenter Earth’s Atmosphere This Week

One of the largest reentries in recent years, ESA’s ERS-2 satellite is coming down this week.

After almost three decades in orbit, an early Earth-observation satellite is finally coming down this week. The European Space Agency’s (ESA) European Remote Sensing satellite ERS-2 is set to reenter the Earth’s atmosphere on or around Wednesday, February 21^st.

February 19, 2024February 19, 2024 by Mark Thompson

Look at How Much the Sun Has Changed in Just Two Years

Image of the Sun from Solar Orbiter (left Feb 2021 and right Oct 2023)

The solar cycle has been reasonably well understood since 1843 when Samuel Schwabe spent 17 years observing the variation of sunspots. Since then, we have regularly observed the ebb and flow of the sunspots cycle every 11 years. More recently ESA’s Solar Orbiter has taken regular images of the Sun to track the progress as we head towards the peak of the current solar cycle. Two recently released images from February 2021 and October 2023 show how things are really picking up as we head toward solar maximum.

February 19, 2024February 19, 2024 by Mark Thompson

What are the Differences Between Quasars and Microquasars?

Quasars are fascinating objects; supermassive black holes that are actively feasting on material from their accretion disks. The result is a jet that can outshine the combined light from the entire galaxy! There are smaller blackholes too that are the result of the death of stars and these also sometimes seem to host accretion disks and jets just like their larger cousins. We call these microquasars and, whilst there are similarities between them, there are differences too.

February 19, 2024February 22, 2024 by Alan Boyle

Odysseus Moon Lander Sends Back Selfies With Earth in the Picture

Odysseus lander selfie with Earth in background — A fisheye photo captured by a camera aboard the Odysseus lander shows the lander itself with Earth in the background. (Credit: Intuitive Machines)

Intuitive Machines’ Odysseus lander has beamed back a series of snapshots that were captured as it headed out from the Earth toward the moon, and one of the pictures features Australia front and center. The shots also show the second stage of the SpaceX Falcon 9 rocket that launched the spacecraft, floating away as Odysseus pushed onward.