Universe Today

October 10, 2024October 10, 2024 by Matt Williams

Exoplanet Discovered in a Binary System Could Explain Why Red Dwarfs Form Massive Planets

This artist's concept illustrates a red dwarf star surrounded by exoplanets. Credit: NASA/JPL-Caltech

In recent years, the number of known extrasolar planets (aka. exoplanets) has grown exponentially. To date, 5,799 exoplanets have been confirmed in 4,310 star systems, with thousands more candidates awaiting confirmation. What has been particularly interesting to astronomers is how M-type (red dwarf) stars appear to be very good at forming rocky planets. In particular, astronomers have detected many gas giants and planets that are several times the mass of Earth (Super-Earths) orbiting these low-mass, cooler stars.

Consider TOI-6383A, a cool dwarf star less than half the mass of the Sun that orbits with an even smaller, cooler companion – the red dwarf star TOI-6383B. In a recent study, an international team of astronomers with the Searching for Giant Exoplanets around M-dwarf Stars (GEMS) survey detected a giant planet transiting in front of the primary star, designated TOI-6383Ab. This planet is similar in size and mass to the system’s companion star, which raises questions about the formation of giant planets in red dwarf star systems.

October 10, 2024October 10, 2024 by Brian Koberlein

Most Mars Meteorites Came From Five Craters

A digital-image mosaic of Mars’ Tharsis plateau shows the extinct volcano Arsia Mons. Credit: NASA/JPL/USGS

Meteorites strike Earth every day. It’s estimated that about 100 – 300 metric tonnes of material strike our planet every year. Most of it consists of sand-grain sized dust that burns up in the atmosphere, but each year a few thousand will reach Earth’s surface.

October 10, 2024October 10, 2024 by Mark Thompson

NASA Reveals the Mind-Boggling Scale of Hurricane Milton seen from Space

We often talk about Jupiter’s Great Red Spot quite candidly but forget that hurricanes can be devastating, destructive forces here on Earth. Hurricane Milton is a reminder of the awful effects here on Earth. It came out of nowhere, appearing in the Gulf of Mexico as a tropical storm and two days later was a category 5 hurricane. It tracked a course and hit land near Siesta Key in Florida. NASA have been tracking the storm from space, recording high sea temperatures that fuelled the storm allowing it to grow. Images have been released from the ISS showing the sheer enormity of the hurricane.

October 10, 2024October 10, 2024 by Mark Thompson

A New Way to Detect Rocky Exoplanet Atmospheres

University of Chicago astronomers have tested a simpler, and more accurate way to determine whether or not exoplanets have atmospheres, a leap in learning more about the potential habitability of far-away planets. Above, an artist’s rendering of what terrestrial exoplanet GJ 1132 b may look like.

The total number of exoplanets discovered to date totals 5,288. Among them are a host of rocky, Earth-like exoplanets but none of them seem to have atmospheres. It’s a fairly challenging observation to make but a team of researchers think they’ve come up with a new, simpler technique. It involves measuring the combined temperature of a star and the exoplanet just before the planet passes behind. If it’s lower than expected, the planet is likely to have an atmosphere regulating its temperature!

October 10, 2024October 10, 2024 by Mark Thompson

How Did Mars Become Uninhabitable?

Mars today bear signs of once having had abundant water, with features resembling valleys and deltas, and minerals that only form in the presence of liquid water. This artist’s concept shows how the Red Planet could have appeared billions of years ago. Credit: NASA/The Lunar and Planetary Institute

Mars has captured our imagination for centuries. Ever since the invention of the telescope our imagination has often drifted toward the possibility of life on Mars. Exploration of the red planet has often revealed that Mars once had plenty of water on its surface but it’s no longer there. Now NASA’s Curiosity rover has found deposits of carbon-rich minerals that could give us a much needed clue.

October 9, 2024October 9, 2024 by Mark Thompson

Good News. Comet Encke Only Threw a Handful of Giant Space Rocks in our Direction

This image taken by NASA's Spitzer Space Telescope shows the comet Encke riding along its pebbly trail of debris. Every October, Earth passes through Encke's wake, resulting in the well-known Taurid meteor shower.

As comets travel along their orbit they dump material along the way. A stream of debris known as the Taurid swarm has been keeping astronomers attention. It’s thought the debris is the remains of comet Encke which has also been fuelling the Taurid meteor shower. The swarm is believed to be composed of mostly harmless, tiny objects but there has been concern that there may be some larger, kilometre size chunks. Thankfully, new observations reveal there are of the order of 9-14 of these 1km rocks.

October 9, 2024October 9, 2024 by Mark Thompson

NASA Announces a New Class of Space Missions: Probe Explorers

NASA has sent a whole host of spacecraft across the Solar System and even beyond. They range from crewed ships to orbit and to the Moon to robotic explorers. Among them are a range of mission classes from Flagships to Discovery Class programs. Now a new category has been announced: Probe Explorers. This new category will fill the gap between Flagship and smaller missions. Among them are two proposed missions; the Advanced X-ray Imaging Satellite and the Probe Far-Infrared Mission for Astrophysics.

October 8, 2024October 8, 2024 by Carolyn Collins Petersen

The Open Star Cluster Westerlund 1, Seen by Webb

Here's Westerlund 1 in all its glory. This dense cluster of bright stars (with diffraction spikes from JWST's optics). They have a variety of sizes depending on their brightness and distance from us in the cluster, and different colors reflecting different types of star. Patches of billowing red gas can be seen in and around the cluster, lit up by the stars. Small stars in the cluster blend into a background of distant stars and galaxies on black. Courtesy ESA/Webb NASA & CSA, M. Zamani (ESA/Webb), M. G. Guarcello (INAF-OAPA) and the EWOCS team.

A long time ago, the Milky Way Galaxy was busy being a prodigious star-formation engine. In those times, it turned out dozens or hundreds of stars per year. These days, it’s rather more quiescent, cranking out only a few per year. Astronomers want to understand the Milky Way’s star-birth history, so they focus on some of the more recent star litters to study. One of them is Westerlund 1, a young so-called “super star cluster” that looks compact and contains a diverse array of older stars. It was part of a burst of star creation around 4 to 5 million years ago.

October 8, 2024October 8, 2024 by Mark Thompson

TESS Finds a Triple Star System that Could Fit within Mercury’s Orbit

This artist’s concept illustrates how tightly the three stars in the system called TIC 290061484 orbit each other. If they were placed at the center of our solar system, all the stars’ orbits would be contained a space smaller than Mercury’s orbit around the Sun. The sizes of the triplet stars and the Sun are also to scale. NASA’s Goddard Space Flight Center

TESS, the Transiting Exoplanet Survey Satellite has been on the lookout for alien worlds since 2018. It has just hit the news again having identified an extreme triple star system where two stars orbit each other every 1.8 days. The third component circles them both in 25 days – this puts the entire system within the orbit of Mercury with a little wriggle room to spare! To visual observers, it looks like a single star but the power of TESS revealed a flicker as the stars line up and pass one another along our line of sight. Eventually, the two inner stars will merge, triggering a supernova event!

October 7, 2024October 7, 2024 by Matt Williams

The JWST Reveals New Things About How Planetary Systems Form

This artist’s impression of a planet-forming disk surrounding a young star shows a swirling “pancake” of hot gas and dust from which planets form. Credit and ©: National Astronomical Observatory of Japan (NAOJ)

Every second in the Universe, more than 3,000 new stars form as clouds of dust and gas undergo gravitational collapse. Afterward, the remaining dust and gas settle into a swirling disk that feeds the star’s growth and eventually accretes to form planets – otherwise known as a protoplanetary disk. While this model, known as the Nebular Hypothesis, is the most widely accepted theory, the exact processes that give rise to stars and planetary systems are not yet fully understood. Shedding light on these processes is one of the many objectives of the James Webb Space Telescope (JWST).

In a recent study, an international team of astronomers led by University of Arizona researchers and supported by scientists from the Max Planck Institute of Astronomy (MPIA) used the JWST’s advanced infrared optics to examine protoplanetary disks around new stars. These observations provided the most detailed insights into the gas flows that sculpt and shape protoplanetary disks over time. They also confirm what scientists have theorized for a long time and offer clues about what our Solar System looked like roughly 4.6 billion years ago.