If you’ve been following exoplanet research over the last couple of years, you’ve definitely heard of K2-18b. Located 124 light years away in the constellation Leo, it’s attracted a lot of attention as it sits squarely in its red dwarf host star’s habitable zone, and measurements of the James Webb Space Telescope show its atmosphere is rich in carbon dioxide and methane. It’s one of the prime candidates for a “Hycean” world - one where a thick hydrogen-rich atmosphere covers a global liquid water ocean. It is such an intriguing target for Search for Extraterrestrial Intelligence (SETI) researchers that they turned two of the most powerful radio telescopes in the world to watch K2-18b’s system. A recent paper, available in pre-print on arXiv, shows that there is likely no artificial narrow-band radio signals that are equivalent to our technology level coming from the planet, despite millions of potential hits.

There have been plenty of attempts to resolve the “Hubble Tension” in cosmology. This feature describes how one of the most important variables in cosmology, the expansion of the universe, takes on different values depending on how you measure it. A new NASA Institute for Advanced Concepts (NIAC) Phase I report on the Cosmic Positioning System (CPS) details another potential solution to it - this one involving a network of five far-flung satellites spread throughout the solar system.

Our solar system is home to a wide diversity of planetary bodies, boasting eight planets, five officially recognized dwarf planets, and almost 1,000 confirmed moons. The eight planets consist of the four rocky (terrestrial) planets of the inner solar system and the four gas giant planets of the outer solar system. The largest planet in our solar system is Jupiter, measuring a radius and mass of 11 and 318 times of Earth, respectively. However, the discovery of exoplanets quickly altered our understanding of planetary sizes, as several have been discovered to have masses and radii several times that of Jupiter. So, how big can planet get, and are there limits to their sizes?

Grounded until at least April, NASA's giant moon rocket is headed back to the hangar this week for more repairs before astronauts climb aboard.

Researchers at University of Victoria's Astronomy Research Centre (ARC) and the University of Minnesota study the changes in the chemical composition at the surface of red giant stars.

One way of studying and understanding distant, hard-to-reach locations elsewhere in the Solar System is to find analogues of them here on Earth. For example, deserts and lava fields are often used to understand aspects of the Martian surface. In new research, scientists collected samples from natural geysers in the Utah desert to try to understand the Solar System's icy ocean moons.

Searching for life beyond Earth has rapidly advanced in recent years. However, directly imaging an exoplanet and all their incredible features remain elusive given the literal astronomical distances from Earth. Therefore, astronomers have settled by exploring exoplanet atmospheres for signatures of life, also called biosignatures. This is currently conducted by analyzing the starlight that passes through an exoplanet’s atmosphere, known as spectroscopy, as it passes in front of its star, also called a transit. But improvements continue to be made to better explore exoplanet atmospheres, specifically cleaning up messy data.

For decades, scientists have searched the skies for signs of extraterrestrial technology. A study from EPFL asks a sharp question: if alien signals have already reached Earth without us noticing, what should we realistically expect to detect today?

Our solar system hosts almost 900 known moons, with more than 400 orbiting the eight planets while the remaining orbit dwarf planets, asteroids, and Trans-Neptunian Objects (TNOs). Of these, only a handful are targets for astrobiology and could potentially support life as we know it, including Jupiter’s moons Europa and Ganymede, and Saturn’s moon Titan and Enceladus. While these moons orbit two of the largest planets in our solar system, what about moons orbiting giant exoplanets, also called exomoons? But, to find life on exomoons, scientists need to find exomoons to begin with.

When the Perseverance rover was sent to Mars, it was largely dedicated to astrobiology. It's driving around an ancient paleolake, Jezero Crater, looking for evidence of past life. But the rover mission is also a testbed for greater autonomous operations. Now, NASA has given the inquisitive rover a way to better navigate the Martian surface with less human intervention.

If humans want to live in space, whether on spacecraft or the surface of Mars, one of the first problems to solve is that of water for drinking, hygiene, and life-sustaining plants. Even bringing water to the International Space Station (ISS) in low Earth orbit costs on the order of tens of thousands of dollars. Thus, finding efficient, durable, and trustworthy ways to source and reuse water in space is a clear necessity for long-term habitation there.

More and more papers are coming out about the upcoming Habitable Worlds Observatory (HWO). As the telescope moves from theory to practice (and physical manifestation), various working groups are discovering, defining, and designing their way to the world’s next major exoplanet observatory. A new paper from researchers at NASA Goddard Space Flight Center adds another layer of analysis - we even just reported on its immediate predecessor two weeks ago. In this one, the researchers compared the ability of the telescope to distinguish between carbon dioxide and methane/water, to come up with a specific wavelength the engineers should design for.

How do galaxies evolve? When did they start forming? Those are questions astronomers and cosmologists are working to answer. The standard path includes early bright starforming activity, a middle age, and then a quiescent old age where they stop making stars. That changes if the galaxy happens to collide with another one, because that spurs new bouts of starbirth. It's been this way since stars and galaxies first began forming, slightly less than a billion years after the Big Bang.

A plethora of newly discovered baryonic (or normal) dark matter signals the first step toward the end of dark matter theory. Or so say the authors of a new paper just accepted by the journal Physical Review D.

Nearly two years after Boeing’s botched Starliner mission to the International Space Station, NASA put the mishap in the same category as the Challenger and Columbia space shuttle disasters — and said the spacecraft wouldn’t carry another crew until dozens of corrective actions are taken.

Theory says that, under the right conditions, massive stars can collapse directly into black holes without exploding as supernovae. But observational evidence of the phenomenon has been hard to get. Now astronomers have found some sequestered in archival data.

Astronomers have found a candidate Jellyfish Galaxy only about 5 billion years after the Big Bang. This is earlier than expected, since the ram pressure stripping responsible for it wasn't thought to be possible so early in the Universe's history. The galaxy could explain the puzzling "Red Nugget" galaxies, but first it has to be confirmed.

The early Universe was a busy place. As the infant cosmos exanded, that epoch saw the massive first stars forming, along with protogalaxies. It turns out those extremely massive early stars were stirring up chemical changes in the first globular clusters, as well. Not only that, many of those monster stars ultimately collapsed as black holes.

We know galaxies by their powerful illumination, generated by multitudes of stars. But some galaxies can be very dim. These are hypothesized to be dark galaxies, or dark matter galaxies. They're theoretical, and only candidates have been identified, but researchers may have confirmed the very first one.

Lunar dust remains one of the biggest challenges for a long-term human presence on the Moon. Its jagged, clingy nature makes it naturally stick to everything from solar panels to the inside of human lungs. And while we have some methods of dealing with it, there is still plenty of experimentation to do here on Earth before we use any such system in the lunar environment. A new paper in Acta Astronautica from Francesco Pacelli and Alvaro Romero-Calvo of Georgia Tech and their co-authors describes two types of flexible Electrodynamic Dust Shields (EDSs) that could one day be used in such an environment.