Could the Clues to Ancient Alien Civilizations Be Hiding in a Bucket of Moon Dust?

Most of our experience with the Search for Extraterrestrial Intelligence (SETI) has been focused on capturing radio signals that alien species have sent out, whether intentionally or unintentionally. That creates a huge “synchronicity” problem - what if there aren’t any alien civilizations broadcasting radio signals now, but there were a billion years ago? The Milky Way is around 13 billion years old - hoping that we exist at the same time as an alien civilization that happens to be actively messaging is a huge leap of faith. But, according to a new paper available in pre-print on arXiv and submitted to the International Journal of Astrobiology by Lewis J Pinault, as associated researcher at the SETI Institute, and his co-authors, we could take a completely alternative approach to trying to find alien civilizations - by looking for evidence of them in lunar dirt.

A New Catalog of Close to 3,000 Supernova Challenges Theories on Dark Energy

The most comprehensive catalogue of exploding white dwarf stars ever assembled has revealed new clues about dark energy, the mysterious force driving the universe’s accelerating expansion.

A New Design For A Plasma Engine Fuels On Only Thin Air

Choosing what orbit to put a satellite in always comes with trade-offs. When it comes to Very Low Earth Orbit (VLEO), between 100-450 km, there are distinct advantages. Remote sensing cameras can take better pictures, comms and radar require less power, and atmospheric drag will automatically clean up dead satellites. But there’s also a cost - air friction requires any satellite in this orbit to use an engine near constantly to stay in orbit, which in turn requires fuel - typically in the form of expensive gases like Xenon. So, as part of his PhD thesis at the University of Stuttgart, which is available in arXiv, Francesco Romano decided to solve that problem by using the very air molecules that cause that friction as fuel for a plasma engine to keep satellites aloft indefinitely in VLEO.

Venus Moon Would Have Been Doomed From The Start, Says New Paper

Venus likely never had a moon and even if it did, it would have soon been torn asunder by the planet’s own gravity, says prominent planetary astrophysicist.

Dense Galaxies Are Carving Out A Bubble in the Early Universe

Light could only travel freely in the Universe after cosmic reionization. Before that, neutral hydrogen stopped photons from travelling. The JWST has found evidence of an overdensity of galaxies carving out a bubble of reionization. Is this how it all started?

What's Carving Active Gullies on Mars? It's Not Water

Scientists were shocked when they received the first images of Martian gullies. They were even more shocked as those gullies appeared to change over time. Their similarities to gullies seen on Earth were uncanny, but all of Earth’s gullies are formed by the water run-off, and Martian is too cold and has too sparse an atmosphere to have liquid water on its surface. Whatever has been causing those changing gullies couldn’t have been water, so what was it? A new paper from Apolline Leclef of the Institut d’Astrophysique Spatiale at Université Paris-Saclay and her colleagues, available in pre-print on arXiv, shows how they are likely caused by CO2 frost turning into a fluid.

NASA's Next Great Observatory Could Spot Oceans on Distant Worlds

We’ve found over 5,500 exoplanets so far. Dozens of them have been in the habitable zone of their parent stars, where, at least in theory, they could host an ocean. But we’ve never definitively found a liquid ocean on another planet. A new paper from researchers Eleanor Cornish and Tyler Robinson of the University of Arizona, available in pre-print on arXiv and submitted to the Astrophysical Journal, looks at a unique way we might be able to find one - by looking for its “glint”.