Universe Today

February 2, 2021February 2, 2021 by Evan Gough

When Galaxies Collide, Black Holes Don’t Always Get the Feast They Were Hoping for

What happens when galaxies collide? Well, if any humans are around in about a billion years, they might find out. That’s when our Milky Way galaxy is scheduled to collide with our neighbour the Andromeda galaxy. That event will be an epic, titanic, collision. The supermassive black holes at the center of both galaxies will feast on new material and flare brightly as the collision brings more gas and dust within reach of their overwhelming gravitational pull. Where massive giant stars collide with each other, lighting up the skies and spraying deadly radiation everywhere. Right?

Maybe not. In fact, there might be no feasting at all, and hardly anything titanic about it.

February 2, 2021February 2, 2021 by Nancy Atkinson

MESSENGER Saw a Meteoroid Strike Mercury

Artist’s illustration depicting how MESSENGER observed the first meteoroid impact on another planet’s surface. Particles (neutral atoms) ejected by the meteoroid skyrocketed over 3,000 miles above Mercury’s surface, outside the bow shock of Mercury’s magnetosphere. There, photons of light turned the neutral particles into charged particles (ions), which one of MESSENGER’s instruments could detect. Credit: modified from Jacek Zmarz

Telescopes have captured meteoroids hitting the Moon and several spacecraft imaged Comet Shoemaker–Levy 9 smacking into Jupiter in 1994. But impacts as they happen on another rocky world have never been observed.

However, the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry and Ranging) mission may have seen an impact take place back in 2013. In looking at archival data from the mission, scientists found evidence of a meteoroid impact on Mercury. While this data isn’t a ‘no-doubt’ photo of the event, it does tell scientists more about impacts and how they affect Mercury’s wispy-thin atmosphere.

February 2, 2021February 1, 2021 by Paul M. Sutter

Astronomers are Starting to Understand the Quasar Lifecycle

Illustration of an active quasar. New research shows that SMBHs eat rapidly enough to trigger them. Credit: ESO/M. Kornmesser

Supermassive black holes have a complicated lifecycle. Sometimes they’re “on”, blasting out tremendous amounts of energy, and sometimes they’re “off’, where they sleep like dragons in their caves. By comparing the proportion of high-energy to low-energy waves emitted by quasars, astronomers are beginning to pin down how many black holes are sleeping, and when they’re likely to wake back up.

February 1, 2021February 1, 2021 by Paul M. Sutter

Galaxy Mergers can Boost Star Formation, and it can Also Shut it Down

It is known today that merging galaxies play a large role in the evolution of galaxies and the formation of elliptical galaxies in particular. However there are only a few merging systems close enough to be observed in depth. The pair of interacting galaxies picture seen here — known as NGC 3921 — is one of these systems. NGC 3921 — found in the constellation of Ursa Major (The Great Bear) — is an interacting pair of disc galaxies in the late stages of its merger. Observations show that both of the galaxies involved were about the same mass and collided about 700 million years ago. You can see clearly in this image the disturbed morphology, tails and loops characteristic of a post-merger. The clash of galaxies caused a rush of star formation and previous Hubble observations showed over 1000 bright, young star clusters bursting to life at the heart of the galaxy pair.

Galaxy mergers are beautiful sights, but ultimately deadly. In the midst of the collision, the combined galaxy will shine brighter than it ever has before. But that glory comes with a price: all those new stars use up all the available fuel, and star formation grinds to a halt.

February 1, 2021February 1, 2021 by Matt Williams

A Sunlike Star Found With Four (No, Five!) Exoplanets Orbiting It

This artist’s impression shows the view from the planet in the TOI-178 system found orbiting furthest from the star. New research by Adrien Leleu and his colleagues with several telescopes, including ESO’s Very Large Telescope, has revealed that the system boasts six exoplanets and that all but the one closest to the star are locked in a rare rhythm as they move in their orbits. Image Credit: ESO/L. Calçada/spaceengine.org

In just nine months (October 31st, 2021), NASA’s long-awaited James Webb Space Telescope (JWST) will finally be launched to space. Once operational, this next-generation observatory will use its powerful infrared imaging capabilities to study all kinds of cosmological phenomena. It will also be essential to the characterization of extrasolar planets and their atmospheres to see if any are habitable.

In anticipation of this, astronomers have been designating exoplanets as viable candidates for follow-up studies. Using data from the Transiting Exoplanet Survey Satellite (TESS), an international team led by MIT researchers discovered four new exoplanets orbiting a Sun-like star about 200 light-years from Earth. This system could be an ideal place for James Webb to spot a habitable planet.

February 1, 2021February 1, 2021 by Nancy Atkinson

A Crater on Venus Indicates the Planet Hasn’t Been Volcanic for a Long Time

Venus may not have had Earth-like tectonic plates or volcanism for the last billion years, according to a new study. A deep look at a giant impact crater on Venus suggests the planet hasn’t experienced any tectonic activity in the recent past, and might be covered with a in a single outer plate. If so, this would essentially rule out any recent volcanic activity on the planet that many consider Earth’s twin.

February 1, 2021February 1, 2021 by Matt Williams

Neutrinos Have a Newly Discovered Method of Interacting With Matter, Opening up Ways to Find Them

SCGSR Awardee Jacob Zettlemoyer, Indiana University Bloomington, led data analysis and worked with ORNL’s Mike Febbraro on coatings, shown under blue light, to shift argon light to visible wavelengths to boost detection. Credit: Rex Tayloe/Indiana University

The neutrino is a confounding little particle that is believed to have played a major role in the evolution of our Universe. They also possess very little mass, have no charge, and interact with other particles only through the weak nuclear force and gravity. As such, finding evidence of their interactions is extremely difficult and requires advanced facilities that are shielded to prevent interference.

One such facility is the Oak Ridge National Laboratory (ORNL) where an international team of researchers are conducting the COHERENT particle physics experiment. Recently, researchers at COHERENT achieved a major breakthrough when they found the first evidence of a new kind of neutrino interaction, which effectively demonstrates a process known as coherent elastic neutrino-nuclear scattering (CEvNS).

February 1, 2021February 1, 2021 by Paul M. Sutter

White Dwarf Atmospheres Might Contain the Pulverized Crusts of Their Dead Planets

Illustration of the internal layers of a white dwarf star. Credit: University of Warwick/Mark Garlick

Astronomers have developed a new technique to search for exoplanets – by looking for their crushed up bones in the atmospheres of white dwarfs. And it’s working.

January 30, 2021January 30, 2021 by Matt Williams

2020 Ties for the Hottest Year on Record

According to multiple sources – which includes NASA, the NOAA, the Berkeley Earth research group, and the Met Office Hadley Centre (UK) – global temperatures over the past few years have been some of the hottest on record. This is the direct result of anthropogenic factors like overpopulation, urbanization, deforestation, and increased greenhouse gas emissions (like carbon dioxide and methane).

According to a recent press release from NASA, in terms of global temperatures, 2020 was the hottest year on record – effectively tying it with 2016 (the previous record-holder). The release includes a dramatic video that illustrates average temperature increases since 1880 and the ecological crises that have taken place just this past year. This is yet another warning of how human agency is impacting the very systems we depend upon for our continued survival.

January 29, 2021January 29, 2021 by Andy Tomaswick

We Now Have a 3D Map of The 525 Closest Brown Dwarfs

Zooniverse brings out the best of the internet – it leverages the skills of average people to perform scientific feats that would be impossible otherwise. One of the tasks that a Zooniverse project called Backyard Worlds: Planet 9 has been working on has now resulted in a paper cataloguing 525 brown dwarfs, including 38 never before documented ones.