Universe Today

June 30, 2022June 30, 2022 by Matt Williams

Tidal Heating Could Make Exomoons Much More Habitable (and Detectable)

An artist's illustration of the Kepler 1625 system. The star in the distance is called Kepler 1625. The gas giant is Kepler 1625B, and the exomoon orbiting it is unnamed. The moon is about as big as Neptune, but is a gas moon. Image: NASA, ESA, and L. Hustak (STScI)

Within the Solar System, most of our astrobiological research is aimed at Mars, which is considered to be the next-most habitable body beyond Earth. However, future efforts are aimed at exploring icy satellites in the outer Solar System that could also be habitable (like Europa, Enceladus, Titan, and more). This dichotomy between terrestrial (rocky) planets that orbit within their a system’s Habitable Zones (HZ) and icy moons that orbit farther from their parent stars is expected to inform future extrasolar planet surveys and astrobiology research.

In fact, some believe that exomoons may play a vital role in the habitability of exoplanets and could also be a good place to look for life beyond the Solar System. In a new study, a team of researchers investigated how the orbit of exomoons around their parent bodies could lead to (and place limits on) tidal heating – where gravitational interaction leads to geological activity and heating in the interior. This, in turn, could help exoplanet-hunters and astrobiologists determine which exomoons are more likely to be habitable.

June 30, 2022June 30, 2022 by Carolyn Collins Petersen

Red Supergiant Stars Bubble and Froth so Much That Their Position in the Sky Seems to Dance Around

This artist’s impression shows the red supergiant star. Using ESO’s Very Large Telescope Interferometer, an international team of astronomers have constructed the most detailed image ever of this, or any star other than the Sun. Credit: ESO/M. Kornmesser

Making a 3D map of our galaxy would be easier if some stars behaved long enough to get good distances to them. However, red supergiants are the frisky kids on the block when it comes to pinning down their exact locations. That’s because they appear to dance around, which makes pinpointing their place in space difficult. That wobble is a feature, not a bug of these massive old stars and scientists want to understand why.

So, as with other challenging objects in the galaxy, astronomers have turned to computer models to figure out why. In addition, they are using Gaia mission position measurements to get a handle on why red supergiants appear to dance.

Artist’s impression of the red supergiant star Betelgeuse as it was revealed with ESO’s Very Large Telescope. It shows a boiling surface and material shed by the star as it ages. Credit: ESO/L.Calçada

June 30, 2022June 30, 2022 by Evan Gough

This is How You Get Multiple Star Systems

G205.46-14.56 clump located in Orion molecular cloud complex. The yellow contours stand for the dense cores discovered by JCMT, and the zoomed-in pictures shows the 1.3mm continuum emission of ALMA observation. These observations give insight into the formation of various stellar systems in dense cores. Image Credit: Qiuyi Luo et al. 2022.

Stars form inside massive clouds of gas and dust called molecular clouds. The Nebular Hypothesis explains how that happens. According to that hypothesis, dense cores inside those clouds of hydrogen collapse due to instability and form stars. The Nebular Hypothesis is much more detailed than that short version, but that’s the basic idea.

The problem is that it only explains how single stars form. But about half of the Milky Way’s stars are binary pairs or multiple stars. The Nebular Hypothesis doesn’t clearly explain how those stars form.

June 30, 2022June 30, 2022 by Andy Tomaswick

The Case is Building That Colliding Neutron Stars Create Magnetars

Magnetars are some of the most fascinating astronomical objects. One teaspoon of the stuff they are made out of would weigh almost one billion tons, and they have magnetic fields that are hundreds of millions of times more powerful than any magnetic that exists today on Earth. But we don’t know much about how they form. A new paper points to one possible source – mergers of neutron stars.

June 29, 2022June 29, 2022 by Carolyn Collins Petersen

A Dying Star’s Last Act was to Destroy all Its Planets

Artist's rendition of a white dwarf from the surface of an orbiting exoplanet. Astronomers have found two giant planet candidates orbiting two white dwarfs. More proof that giant planets can surve their stars' red giant phases. Image Credit: Madden/Cornell University

When white dwarfs go wild, their planets suffer through the resulting chaos. The evidence shows up later in and around the dying star’s atmosphere after it gobbles up planetary and cometary debris. That’s the conclusion a team of UCLA astronomers came to after studying the nearby white dwarf G238-44 in great detail. They found a case of cosmic cannibalism at this dying star, which lies about 86 light-years from Earth.

If that star were in the place of our Sun, it would ingest the remains of planets, asteroids, and comets out to the Kuiper Belt. That expansive buffet makes this stellar cannibalism act one of the most widespread ever seen.

June 29, 2022June 29, 2022 by Andy Tomaswick

The Rings of Uranus and Neptune Could Help map Their Interiors

Mapping the interior of the ice giants is difficult, to say the least. Not only are they far away and therefore harder to observe, but their constant ice cover makes it extremely hard to detect what lies underneath. So scientists must devise more ingenious ways to see what’s inside them. A team from the University of Idaho, Cal Tech, Reed College, and the University of Arizona think they might have come up with a way – to look at the structure of Neptunes’ and Uranus’ rings.

June 29, 2022June 29, 2022 by Evan Gough

A New Map of Mars, Made From 51,000 Orbital Images

Seen are six views of the Nili Fossae region of Mars captured by the Compact Reconnaissance Imaging Spectrometer for Mars, or CRISM, one of the instruments aboard NASA’s Mars Reconnaissance Orbiter. The varying colors represent minerals on the Martian surface seen in different wavelengths of light. Credits: NASA/JPL-Caltech/JHU-APL

When NASA sent the Mars Reconnaissance Orbiter (MRO) to the red planet in 2006, the spacecraft took an instrument with it called CRISM—Compact Reconnaissance Imaging Spectrometer for Mars. CRISM’s job is to produce maps of Mars’ surface mineralogy. It’s been an enormous success, but unfortunately, the loss of its last cryocooler in 2017 means the spectrometer can only undertake limited observations.

But CRISM is going out with a bang, creating one final image of the surface of Mars that NASA will release in batches over the next six months.

June 29, 2022June 29, 2022 by Nancy Atkinson

Cygnus Boosts the International Space Station for the First Time. NASA Can Now Potentially Keep the Station Aloft Without Russia’s Progress Spacecraft

Cygnus docked to the International Space Station prior to performing an operational reboost. Image via Northrup Grumman.

Northrup Grumman’s Cygnus cargo spacecraft conducted a successful reboost of the International Space Station over the past weekend, on Saturday, June 25, 2022. The Cygnus NG-17 “Piers Sellers” is the first US-based spacecraft to provide a substantial orbital adjustment to the ISS since the space shuttles retired in 2011. Russia’s Progress cargo spacecraft has been the primary source for station reboosts, attitude control, and debris avoidance maneuvers.

“This reboost of the ISS using Cygnus adds a critical capability to help maintain and support the space station,” said Steve Krein, vice president, civil and commercial space, tactical space systems, Northrop Grumman, in a press release. “It also demonstrates the enormous capability Cygnus offers the ISS and future space exploration efforts.”

June 29, 2022June 29, 2022 by David Dickinson

Record ‘Fast Nova’ Flares Over a Single Day

A galactic nova flared briefly into naked eye visibility for a day, before vanishing from sight.

Some stars burn bright but brief. These transitory novae pepper the sky, with one flaring into naked eye visibility every few years… but it was a recent brief appearance of just such a ‘new star’ that gave astronomers a chance to probe the secrets of the Universe.

June 28, 2022June 28, 2022 by Nancy Atkinson

A Star has Grown Spiral Arms

Protostellar disk around a star at the galactic center. Image credit: Lu et al.

Astronomers using the ALMA Observatory have discovered an unusual, massive star near the center of our galaxy, a star that has two spiral arms. The arms are part of an accretion disk, a broad disk of dust and gas surrounding the protostar. While this is not the first star to be seen with such rare arm-like features, researchers say they believe they can track the formation of the spiral arms to a close encounter the star had with another object.