Universe Today

March 1, 2025March 1, 2025 by Matt Williams

Good News! The Subaru Telescope Confirms that Asteroid 2024 YR4 Will Not Hit Earth.

Artist's impression of asteroid 2024 YR4. Concerns about a potential impact have dissipated as more observational data comes in. Credit: ESA

On December 27th, 2024, the Chilean station of the Asteroid Terrestrial-impact Last Alert System (ATLAS) detected 2024 YR₄. This Near-Earth Asteroid (NEA) belongs to the Apollo group, which orbits the Sun with a period of approximately four years. For most of its orbit, 2024 YR4 orbits far from Earth, but sometimes, it crosses Earth’s orbit. The asteroid was spotted shortly after it made a close approach to Earth on Christmas Day 2024 and is now moving away. Additional observations determined it had a 1% probability of hitting Earth when it makes its next close pass in December 2032.

This led the International Asteroid Warning Network (IAWN) – overseen by the United Nations Office for Outer Space Affairs (UNOOSA) – to issue the first-ever official impact risk notification for 2024 YR₄. The possibility of an impact also prompted several major telescopes to gather additional data on the asteroid. This included the Subaru Telescope at the Mauna Kea Observatory in Hawaii, which captured images of the asteroid on February 20th, 2025. Thanks to the updated positional data from these observations, astronomers have refined the asteroid’s orbit and determined that it will not hit Earth.

February 28, 2025February 28, 2025 by Matt Williams

Detection of a Space Capsule Entering Earth’s Atmosphere with Distributed Acoustic Sensing (DAS)

The sample return capsule from NASA’s OSIRIS-REx mission is seen shortly after touching down in the desert, Sunday, Sept. 24, 2023. Credit: NASA

On December 3rd, 2018, NASA’s Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) successfully rendezvoused with the Near-Earth Asteroid (NEA) 101955 Bennu. Over the next two years, the mission collected rock and regolith samples from the asteroid’s surface. By September 24th, 2023, the mission’s sample return capsule (SRC) entered Earth’s atmosphere and was collected by NASA scientists. Analysis of these samples is already providing insight into what conditions were like during the early Solar System.

According to a recent study, the known trajectory and timing of the SRC’s return provided a rare opportunity to record geophysical signals produced by the capsule using a new method. Because it was traveling at hypersonic speeds as it flew through the atmosphere, the SRC’s return produced a sonic boom that impacted the ground. Using distributed acoustic sensing (DAS) interrogators and surface-draped fiber-optic cables, the team carried out the first reported recording of an SRC reentry with distributed fiber-optic sensing technology.

February 28, 2025February 28, 2025 by Evan Gough

Andromeda’s Dwarf Galaxies Reveal Unique Star Formation Histories

The Hubble Space Telescope examined 36 dwarf galaxies around the Andromeda Galaxy and measured their star formation histories. Andromeda is the bright spindle-shaped object at image center. The most prominent dwarf galaxy is M32 (NGC 221), a compact ellipsoidal galaxy that might be the remnant core of a larger galaxy that collided with Andromeda a few billion years ago. Image Credit: NASA, ESA, Alessandro Savino (UC Berkeley), Joseph DePasquale (STScI), Akira Fujii DSS2

The Andromeda Galaxy, our nearest large neighbour, has 36 identified dwarf galaxies. The Hubble telescope took images of Andromeda and its dwarfs during more than 1,000 orbits, creating a precise 3D map. Astronomers used these observations to reconstruct the dwarf galaxies’ star formation histories.

The results show that their environment plays a critical role in their star formation and their quenching.

February 28, 2025February 28, 2025 by Evan Gough

Rogue Planets are Born in Young Star Clusters

This JWST image shows the Trapezium Cluster and the inner region of the Orion Nebula. In the year 2,000, astronomers found evidence of planetary mass objects floating freely in the nebula, not orbiting any stars. New research shows that these free-floating planets formed in powerful interactions between the disks around young stars. Image Credit: NASA, ESA, CSA /M. McCaughrean, S. Pearson

Rogue planetary-mass objects, also known as free-floating planets (FFPs) drift through space alone, unbound to any other objects. They’re loosely defined as bodies with masses between stars and planets. There could be billions, even trillions of them, in the Milky Way.

Their origins are unclear, but new research says they’re born in young star clusters.

February 28, 2025March 1, 2025 by Matt Williams

How Brine Shrimp Adapted to Mars-like Conditions

The idea that Mars could have supported life at one time is the subject of ongoing debate. Image credit: NASA

The effects of Climate Change on Earth’s living systems have led to a shift in biological studies, with attention now being focused on the boundaries within which life can survive. Studying life forms that can thrive in extreme environments (extremophiles) is also fundamental to predicting if humans can live and work in space for extended periods. Last, but not least, these studies help inform astrobiological studies, allowing scientists to predict where (and in what form) life could exist in the Universe.

In a recent study, a team of Italian researchers used brine shrimp (Artemia franciscana) in the earliest stage of development (nauplii) and subjected them to Mars-like pressure conditions. Their results indicate that while the nauplii experienced physiological changes, their development remained largely unchanged. This not only demonstrates that extremophiles show great adaptability and can survive in Mars-like conditions. It also indicates that similar life forms could be found elsewhere in the Universe, representing new opportunities for astrobiological research.

February 28, 2025February 28, 2025 by Carolyn Collins Petersen

A New Way to Measure Where the Milky Way’s Dark Matter Is

The Large Magellanic Cloud, a dwarf satellite galaxy orbiting the Milky Way, causing the larger galaxy to “wobble,” imparting measurable accelerations to Milky Way pulsars. They, in turn, help chart the distribution of dark matter in the Galaxy. Courtesy: NASA.

Our Milky Way Galaxy is rich in dark matter. The problem is, we can’t see where it’s distributed because, well, it’s dark. We also don’t completely understand how it’s distributed—in clumps or what? A team at the University of Alabama-Huntsville has figured out a way to use solitary pulsars to map this stuff and unveil its effect on the galaxy.

February 28, 2025February 28, 2025 by Mark Thompson

Could Neutrinos Tell Us About the Inside of the Sun?

The sun and its atmosphere consist of several zones or layers.

Neutrinos generated through solar fusion reactions travel effortlessly through the Sun’s dense core. Each specific fusion process creates neutrinos with distinctive signatures, potentially providing a method to examine the Sun’s internal structure. Multiple neutrino detection observatories on Earth are now capturing these solar particles, which can be analysed alongside reactor-produced neutrinos with the data eventually enabling researchers to construct a detailed map of the interior of the Sun.

February 28, 2025February 28, 2025 by Andy Tomaswick

A Giant Ribbon Can Pull Payloads Along

Innovation is a history of someone trying to build a better mouse trap – or at least that’s how it’s described in business school. But what happens if someone tries to build a better version of something that isn’t even commonly used yet? Maybe we will soon find out, as NASA recently supported an effort to build a better type of solar sail as part of its Institute for Advanced Concepts (NIAC) program.

February 28, 2025February 28, 2025 by Mark Thompson

Photonic Lightsails are our Best Shot at Reaching Another Star

Chemical rockets are loud, noisy and can only get us so far. If we want to reach another star system, we’ll need something better—either super energy-dense fuel to improve the efficiency of chemical rockets or a way to push spacecraft using beams of energy, like a photonic lightsail. A new paper looks at the pros and cons of lightsails, figures out the best setup to carry a small payload to another star while humans are still alive to see it, and checks out what materials might actually work for this kind of mission.

February 28, 2025February 28, 2025 by Mark Thompson

DARPA Wants to Build Structures in Orbit, Without Needing a Launch from Earth

Artist's concept depicts structural assembly and novel composite-forming process experiments to be conducted in space in 2026 during Phase 3 of DARPA's NOM4D program. Source: University of Illinois Urbana-Champaign

Any satellite sent to space must be able to deal with the battle with Earth’s gravitational pull, withstanding the harsh conditions of launch before reaching the zero-gravity environment it was designed for. But what if we could send raw materials into orbit and build the satellite there instead? DARPA (the Defence Advanced Research Projects Agency) has formed partnerships with a number of universities to develop 3D printing technology and in-orbit assembly of satellite components. It’s recently put out a new request for proposals to explore biological growth mechanisms in space – the exciting prospect of living organisms that can increase in size, develop structures, and repair themselves.