Universe Today

January 2, 2025January 2, 2025 by Mark Thompson

This Particle Only Has Mass When Moving in One Direction

The quasiparticle, called a semi-Dirac fermion, was first theorized 16 years ago, but was only recently spotted inside a crystal of semi-metal material called ZrSiS. The observation of the quasiparticle opens the door to future advances in a range of emerging technologies from batteries to sensors, according to researchers who made the discovery. Credit: Yinming Shao / Penn State

Particle physics is not everyone’s cup of tea. A team of physicists have theorised the existence of a strange type of particle that behaves differently depending on its direction of travel—massless in one direction but possessing mass when moving the other way! This strange, elusive particle, known as a semi-Dirac fermion or “quasiparticle,” has actually been observed in action. To detect it, researchers cooled a semi-metal crystal to near absolute zero, exposed it to a powerful magnetic field and infrared light, and successfully captured the signal of these unusual quasiparticles.

January 1, 2025January 1, 2025 by Mark Thompson

Crisscrossing Dust Devil Tracks Across the Surface of Mars

Dust Devils on Mars - NASA/JPL-Caltech/University of Arizona

An incredible image of Mars has been released that captures the relentless activity of dust devils, swirling across the planet’s surface. These Martian whirlwinds form, move across the surface and dissipate before others take their place. The image was taken by the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter in September 2022 and shows part of the Haldane Crater, where dust devils have left their mark on the landscape. Scientists study the image tracks and the rate at which dust accumulates on Mars, helping them better understand the planet’s atmospheric processes.

January 1, 2025January 1, 2025 by Andy Tomaswick

A Long-Term Lunar Infrastructure Hub Named After the Object That Created the Moon

Getting back to the Moon is the primary goal of NASA’s Artemis program, but what do we do once we get there? That is the challenge tackled by a group of students at the University of Illinois Urbana-Champaign, who wrote a proposal for a lunar infrastructure module they call the Trans-lunar Hub for Exploration, ISRU, and Advancement – or THEIA, after the proposed object that crashed into the Earth that created the Moon as we know it today. Their submission was part of the NASA Revolutionary Aerospace Systems Concepts – Academic Linkage project, where teams from various academic institutions submitted papers focusing on the theme of Sustained Lunar Evolution for 2024.

January 1, 2025January 1, 2025 by Brian Koberlein

New Study of Supernovae Data Suggests That Dark Energy is an Illusion

The evolution of the Universe as we know it. Credit: NASA

Dark energy is central to our modern understanding of cosmology. In the standard model, dark energy is what drives the expansion of the Universe. In general relativity, it’s described by a cosmological constant, making dark energy part of the structure of space and time. But as we’ve gathered more observational evidence, there are a few problems with our model. For one, the rate of cosmic expansion we observe depends on the observational method we use, known as the Hubble tension problem. For another, while we assume dark energy is uniform throughout the cosmos, there are some hints suggesting that might not be true. Now a new study argues we’ve got the whole thing wrong. Dark energy, the authors argue, doesn’t exist.

January 1, 2025January 1, 2025 by Scott Alan Johnston

New Glenn Completes a Hotfire Test. Next… Flight?

New Glenn during successful integrated vehicle hotfire on December 27. (Credit: Blue Origin)

Blue Origin has achieved an important milestone with its New Glenn NG-1 rocket, successfully completing a 24-second hotfire of the rocket’s BE-4 engines in preparation for an expected test flight in the coming days.

December 31, 2024December 31, 2024 by Matt Williams

A Young Exoplanet's Atmosphere Doesn't Match its Birthplace

The natal disk of PDS 70 with new planet PDS 70b (bright spot on the right). Credit: ESO/A. Müller et al.

If the modern age of astronomy could be summarized in a few words, it would probably be “the age of shifting paradigms.” Thanks to next-generation telescopes, instruments, and machine learning, astronomers are conducting deeper investigations into cosmological mysteries, making discoveries, and shattering preconceived notions. This includes how systems of planets form around new stars, which scientists have traditionally explained using the Nebular Hypothesis. This theory states that star systems form from clouds of gas and dust (nebulae) that experience gravitational collapse, creating a new star.

The remaining gas and dust then settle into a protoplanetary disk around the new star, which gradually coalesces to create planets. Naturally, astronomers theorize that the composition of the planets would match that of the disk itself. However, when examining a still-developing exoplanet in a distant star system, a team of astronomers uncovered a mismatch between the gases in the planet’s atmosphere and those within the disk. These findings indicate that the relationship between a protoplanetary disk and the planets they form might be more complicated.

December 31, 2024December 31, 2024 by David Dickinson

The Quadrantid Meteors and More Ring in 2025

This Weekend: Catch the Quadrantids at their annual peak, Earth at perihelion and the Moon blotting out Saturn.

Quads — An early Quadrantid meteor from late 2016. Credit: Eliot Herman

Ready for another amazing year of skywatching? The very first weekend of 2025 offers up a flurry of wintertime astronomy events, eluding a swift meteor shower, a January ‘SuperSun,’ and a lunar planetary pair up at dusk.

December 31, 2024December 31, 2024 by Andy Tomaswick

A New Mission Watches Meteoroids Hit the Far Side of the Moon

Sometimes, it’s hard to remember that Earth is constantly being bombarded by literally tons of space debris daily. The larger bits form what we know as shooting stars, and most burn up in the atmosphere. Still, throughout our planet’s history, giant versions have caused devastation unlike anything else seen on this planet. Tracking these types of objects is typically done from the Earth, but a new mission set out by researchers in Italy has a novel idea – why not try to learn more about potential impactors by watching them hit the far side of the Moon?

December 30, 2024December 30, 2024 by Mark Thompson

Even Stars Can Get the Hiccups

An artist’s impression of Pulsational Pair Instability, credit: Gemini Observatory/NSF/AURA/ illustration by Joy Pollard

Stars come in all manner of sizes and temperatures. Many of the massive ones are nearing the end of their lives and at some point in the next few million years, will detonate as supernova explosions. Observing the early stages of these events is tricky though as we can never be sure when they will go pop! It would be great if we could narrow down the timeframe to help hone our search. One theorised phase is that massive stars can ‘hiccup’ with its core expanding and contracting rapidly. This is known as ‘pulsational pair-instability’ and finally a team of astronomers have actually caught a star having the hiccups!

December 30, 2024December 30, 2024 by Mark Thompson

Hotter White Dwarfs Get Puffier

Concept art of two white dwarf stars with the same mass but different temperatures. The hotter star (left) is slightly puffier, while the cooler star (right) is more compact. Credit:Roberto Molar Candanosa/Johns Hopkins University

When our Sun dies, it will turn into a white dwarf. They are a common aspect of stellar evolution and a team of researchers have now turned their attention onto them. They have just completed a survey of 26,000 white dwarfs and confirmed a long-predicted theory that the hotter the star, the puffier it is! This new study will help us to understand white dwarfs and the processes that drive them.