Universe Today

June 10, 2024June 10, 2024 by Evan Gough

The Milky Way’s Last Merger Event Was More Recent Than Thought

Our home galaxy as seen by the European Space Agency’s Gaia satellite. Image Credit: ESA/Gaia/DPAC

The Milky Way is only as massive as it is because of collisions and mergers with other galaxies. This is a messy process, and we see the same thing happening with other galaxies throughout the Universe. Currently, we see the Milky Way nibbling at its two satellite galaxies, the Large and Small Magellanic Clouds. Their fate is likely sealed, and they’ll be absorbed into our galaxy.

Researchers thought the last major merger occurred in the Milky Way’s distant past, between 8 and 11 billion years ago. But new research amplifies the idea that it was much more recent: less than 3 billion years ago.

June 9, 2024June 9, 2024 by Matt Williams

Instead of Losing its Atmosphere, an Exoplanet Puffed Up and Held Onto it

Artist's impression of the "hot Neptune" Phoenix orbiting its red giant star. Credit: Credit: Roberto Molar Candanosa/JHU

To date, astronomers have confirmed the existence of 5638 extrasolar planets in 4,199 star systems. In the process, scientists have found many worlds that have defied expectations. This is certainly the case regarding “hot Neptunes,” planets that are similar to the “ice giants” of the outer Solar System but orbit much closer to their stars. But when a Johns Hopkins University-led team of astronomers discovered TIC365102760 b (aka. Pheonix), they observed something entirely unexpected: a Neptune-sized planet that retained its atmosphere by puffing up.

June 9, 2024June 9, 2024 by Scott Alan Johnston

Carbon is Surprisingly Abundant in an Early Galaxy

Deep field image from JWST Credit: NASA, ESA, CSA, STScI, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Phill Cargile (CfA)

The James Webb Space Telescope (JWST) has once again found evidence that the early universe was a far more complex place than we thought. This time, it has detected the signature of carbon atoms present in a galaxy that formed just 350 million years after the Big Bang – one of the earliest galaxies ever observed.

June 8, 2024June 8, 2024 by Andy Tomaswick

Euclid is Finding Free Floating Planets in Orion Too

There are likely millions of “rogue” or free-floating planets (FFPs) spread through the galaxy. These planets, which aren’t big enough to become stars but also aren’t beholden to a star’s gravity, are some of the hardest objects for astronomers to spot, as they don’t give off their own light, and can only be seen when they cross in front of something that does give off its own light. Enter Euclid, a space telescope that launched last year. Its primary mission is to observe the universe’s history, but a new paper describes an exciting side project – finding FFPs in Orion.

June 8, 2024June 8, 2024 by Allen Versfeld

Where Did Venus's Water Go?

HCO+ molecules reacting in the atmosphere of Venus. Credit: Aurore Simonnet/LASP/CU Boulder — In Venus' upper atmosphere, hydrogen atoms, orange, whiz into space, leaving behind carbon monoxide molecules, blue and purple. (Credit: Aurore Simonnet/LASP/CU Boulder)

It should not be surprising that Venus is dry. It is famous for its hellish conditions, with dense sulphurous clouds, rains of acid, atmospheric pressures comparable to a 900 meter deep lake, and a surface temperature high enough to melt lead. But it’s lack of water is not just a lack of rain and oceans: there’s no ice or water vapour either. Like Earth, Venus is found within our Solar System’s goldilocks zone, so it would have had plenty of water when it was first formed. So where did all of Venus’s water go?

June 7, 2024June 7, 2024 by Mark Thompson

We’re Now Just Weeks Away from a Stellar Explosion You Can See With Your Own Eyes

I’ve seen some pretty incredible things using my eyes.. First off of course, is the stunning sight of a dark star filled sky, then there is the incredible sight of the Andromeda Galaxy 2.5 million light years away. Planets too can of course be seen as they slowly move across the sky but it’s a little more unusual to see something that reminds us the Universe changes. Well, we have an opportunity in just a few weeks time. The star T Corona Borealis (T CrB) will brighten about 1,500 times so it can be seen with the unaided eye. Miss it though and you will have to wait another 80 years!

June 7, 2024June 7, 2024 by Carolyn Collins Petersen

Globular Clusters Should Contain More Intermediate-mass Black Holes

The M15 Globular Cluster (aka. Great Hercules Cluster). Astronomers suspect the existence of one or more intermediate-mass black holes at its heart. Credit: NASA/ESA/HST

We live in a Universe studded with black holes. Countless stellar mass and supermassive ones exist in our galaxy and most others. It’s likely they existed as so-called “primordial” black holes in the earliest epochs of cosmic history. Yet, there seems to be a missing link category: intermediate-mass black holes (IMBH). Astronomers have searched for these rare beasts for years and there’s only one possible observation thanks to gravitational-wave data. So, where are they?

June 6, 2024June 6, 2024 by Matt Williams

Astronauts are Practicing Lunar Operations in New Space Suits

Astronauts were fully suited while conducting mission-like maneuvers in the full-scale build of the Starship human landing system’s airlock which will be located inside Starship under the crew cabin. Credit: SpaceX

Through the Artemis Program, NASA will send astronauts to the lunar surface for the first time since 1972. While the challenges remain the same, the equipment has evolved, including the rocket, spacecraft, human landing system (HLS), and space suits. In preparation for Artemis III (planned for September 2026), NASA recently conducted a test where astronauts donned the new space suits developed by Axiom Space and practiced interacting with the hardware that will take them to the Moon.

June 6, 2024June 6, 2024 by Evan Gough

An Earth-sized Exoplanet Found Orbiting a Jupiter-Sized Star

This artist's illustration shows the exoplanet SPECULOOS-3 b orbiting its red dwarf star. The planet is as big around as Earth, while its star is slightly bigger than Jupiter – but much more massive. The planet is a prime candidate for follow-up studies with the JWST. Credit: NASA/JPL-Caltech

Red dwarf stars, also known as M-dwarfs, dominate the Milky Way’s stellar population. They can last for 100 billion years or longer. Since these long-lived stars make up the bulk of the stars in our galaxy, it stands to reason that they host the most planets.

Astronomers examined one red dwarf star named SPECULOOS-3, a Jupiter-sized star about 55 light-years away, and found an Earth-sized exoplanet orbiting it. It’s an excellent candidate for further study with the James Webb Space Telescope.

June 6, 2024June 6, 2024 by Andy Tomaswick

A Mission to Uranus Could Also be a Gravitational Wave Detector

Despite being extraordinarily difficult to detect for the first time, gravitational waves can be found using plenty of different techniques. The now-famous first detection at LIGO in 2015 was just one of the various ways scientists had been looking. A new paper from researchers from Europe and the US proposes how scientists might be able to detect some more by tracking the exact position of the upcoming Uranus Orbiter and Probe (UOP).