Universe Today

August 5, 2024August 5, 2024 by Matt Williams

Habitable Planet’s Orbiting Red Dwarf Suns Could at Risk from Far-Ultraviolet Radiation

Artist's depiction of red-dwarf-flare. Image credit: Casey Reed/NASA

The question of whether or not red dwarf stars can support habitable planets has been subject to debate for decades. With the explosion in exoplanet discoveries in the past two decades, the debate has become all the more significant. For starters, M-type (red dwarf) stars are the most common in the Universe, accounting for 75% of the stars in our galaxy. Additionally, exoplanet surveys indicate that red dwarfs are particularly good at forming Earth-like rocky planets that orbit within their circumsolar habitable zones (CHZs).

Unfortunately, a considerable body of research has shown that planets orbiting red dwarf suns would be subject to lots of flare activity – including some so powerful they’re known as “superflares.” In a recent study led by the University of Hawai’i, a team of astrophysicists revealed that red dwarf stars can produce stellar flares with significantly more far-ultraviolet radiation than previously expected. Their findings could have drastic implications for exoplanet studies and the search for extraterrestrial life on nearby rocky planets.

August 5, 2024August 5, 2024 by Mark Thompson

Starlink Direct-to-Cell Satellites are Coming. What Will Be Their Impact on Astronomy?

Mention the name Starlink among the astronomy community and you will often be greeted with a shudder. There are now thousands of Starlink satellites orbiting Earth providing internet connectivity to every corner of the Earth. Many believe they are making astronomy difficult but now, SpaceX is launching another service; ‘direct-to-cell’ technology that will allow mobile phones to use satellites to send text messages as early as this year. Voice and data services are likely to follow on quickly next year. With smaller antennae at a lower altitude what is their impact on astronomy?

August 5, 2024August 5, 2024 by Evan Gough

Fast-Tracking the Search for Habitable Worlds

Astronomers have detected thousands of planets, including dozens that are potentially habitable. To winnow them down, they need to understand their atmospheres and other factors. (NASA Illustration)

Modern astronomy would struggle without AI and machine learning (ML), which have become indispensable tools. They alone have the capability to manage and work with the vast amounts of data that modern telescopes generate. ML can sift through large datasets, seeking specified patterns that would take humans far longer to find.

The search for biosignatures on Earth-like exoplanets is a critical part of contemporary astronomy, and ML can play a big role in it.

August 5, 2024August 5, 2024 by Mark Thompson

Astronomers See Planets Forming Around Binary Stars

Artist's illustration of binary star planet formation. Credit: S. Dagnello, NSF/AUI/NRAO

Over 5,000 exoplanets have been discovered around distant star systems. Protoplanetary disks have been discovered too and it’s these, out of which all planetary systems form. Such disks have recently been found in two binary star systems. The stellar components in one have a separation of 14 astronomical units (the average distance between the Earth and Sun is one astronomical unit) and the other system has a separation of 22 astronomical units. Studying systems like these allow us to see how the stars of a binary system interact and how they can distort protoplanetary disks.

August 2, 2024August 2, 2024 by Matt Williams

China's Lunar Samples Contain Graphene Flakes

Artist’s impression of the graphenes (C24) and fullerenes found in a Planetary Nebula. The detection of graphenes and fullerenes around old stars as common as our Sun suggests that these molecules and other allotropic forms of carbon may be widespread in space. Credits: IAC; original image of the Helix Nebula (NASA, NOAO, ESA, the Hubble Helix Nebula Team, M. Meixner, STScI, & T.A. Rector, NRAO.)

In 2004, scientists at the University of Manchester first isolated and investigated graphene, the supermaterial composed of single-layer carbon atoms arranged in a hexagonal honeycomb lattice. Since then, it has become a wonder, with properties that make it extremely useful in numerous applications. Among scientists, it is generally believed that about 1.9% of carbon in the interstellar medium (ISM) exists in the form of graphene, with its shape and structure determined by the process of its formation.

As it happens, there could be lots of this supermaterial on the surface of the Moon. In a recent study, researchers from the Chinese Academy of Science (CAS) revealed naturally formed graphene arranged in a special thin-layered structure on the Moon. These findings could have drastic implications for our understanding of how the Moon formed and lead to new methods for the manufacture of graphene, with applications ranging from electronics, power storage, construction, and supermaterials. They could also prove useful for future missions that will create permanent infrastructure on the lunar surface.

August 2, 2024August 2, 2024 by Nancy Atkinson

The Surface of Dimorphos is Surprisingly New

Simulation of Dimorphos. Credit: University of Michigan/Yun Zhang and Johns Hopkins APL/Olivier Barnouin

When NASA’s DART mission intentionally slammed into Dimorphos in September 2022, the orbit of the moonlet was altered. Researchers have studied the photos and data taken by DART before its impact, learning more about the geology of the Didymos/Dimorphos system. They have now estimated the surface age of both the asteroid and its moon. The asteroid Didymos has a surface age of 12.5 million years, while the moon Dimorphos is only 300,000 years old.

Additionally, the DART researchers concluded both Didymos and Dimorphos are rubble piles, with Dimorphos likely inheriting its boulders from Didymos.

“It’s a pile of gravel and boulders (and some sand/dust) held together by its own gravity, and really not anything else,” said Andy Rivkin, DART investigation team co-lead at the Johns Hopkins Applied Physics Lab (APL), on Bluesky. “There’s really no cohesion between different pieces of gravel or rocks on Dimorphos.”

August 2, 2024August 2, 2024 by Andy Tomaswick

A Tower On The Moon Could Provide Astronauts With Light, Power, and Guidance

Technologies for enabling NASA’s Artemis mission are coming thick and fast, as plenty of problems must be solved before a permanent human presence on the Moon can be established. A novel idea from Honeybee Robotics, one of the most prominent space technology companies now owned by Blue Origin, could solve plenty of them with one piece of infrastructure. The Lunar Utility Navigation with Advanced Remote Sensing and Autonomous Beaming for Energy Redistribution, or LUNARSABER (which must have been named by someone who really likes Star Wars), is a 100m tall pole that can hold one ton of equipment on top of it. It could serve as a central power, communications, and lighting hub of an Artemis base and part of a mesh network with other places of interest on the Lunar surface.

August 2, 2024August 2, 2024 by Evan Gough

Scientists Want to Use the Moon to Safeguard Earth’s Biodiversity

The ESA lunar base, showing its location within the Shackleton Crater at the lunar south pole. New research proposes building a repository at one of the lunar poles to safeguard Earth's biodiversity. Credit: SOM/ESA

There’s something wrong with us.

We’ve risen to prominence on a world that’s positively “rippling with life,” as Carl Sagan described it. The more we study our planet, the more we find life eking out an existence in the most unlikely of places.

Yet we seem destined to drive many species to extinction, even though we see those extinctions coming from miles away.

As an indication of how serious the problem is, one group of researchers suggests we use the Moon—yes, the Moon—as a safe repository for Earth’s biodiversity.

August 1, 2024August 1, 2024 by Evan Gough

How Oumuamua Changes Our Perspective on Galactic Panspermia

Artist’s impression of the first interstellar asteroid/comet, "Oumuamua". This unique object was discovered on 19 October 2017 by the Pan-STARRS 1 telescope in Hawaii. Credit: ESO/M. Kornmesser

Panspermia is an innately attractive idea that’s gained prominence in recent decades. Yet, among working scientists, it gets little attention. There are good reasons for their relative indifference, but certain events spark renewed interest in panspermia, even among scientists.

The appearance of Oumuamua in our Solar System in 2017 was one of them.

August 1, 2024August 1, 2024 by Evan Gough

A New Model Explains How Gas and Ice Giant Planets Can Form Rapidly

Artist's impression of a young star surrounded by a protoplanetary disc made of gas and dust. According to new research, ring-shaped, turbulent disturbances (substructures) in the disk lead to the rapid formation of several gas and ice giants. Credit: LMU / Thomas Zankl, crushed eyes media

The most widely recognized explanation for planet formation is the accretion theory. It states that small particles in a protoplanetary disk accumulate gravitationally and, over time, form larger and larger bodies called planetesimals. Eventually, many planetesimals collide and combine to form even larger bodies. For gas giants, these become the cores that then attract massive amounts of gas over millions of years.

But the accretion theory struggles to explain gas giants that form far from their stars, or the existence of ice giants like Uranus and Neptune.