Why Most Exoplanets Are Magma Worlds

In astronomy, there is a concept called “degeneracy”. It has nothing to do with delinquent people, but instead is used to describe data that could be interpreted multiple ways. In some cases, that interpretation is translated into exciting new possibilities. But many times, when that happens, other, more mundane explanations are ignored for the publicity that the more interesting possibilities provide. That seems to have been the case for many “sub-Neptune” exoplanets discovered recently. Some theories have described them as Hycean worlds - worlds that are filled with water oceans or ice. But a new paper from Robb Calder of the University of Cambridge and his co-authors shows that, most likely, these planets are almost all made of molten lava instead.

The First Alien Civilization We Encounter Will Be Extremely Loud

When we gaze up at the night sky, we assume that what we're seeing is a representative population of similar stars at similar distances. But it's not. The stars we see are a mixture of massive and small, distant and near. In fact, we can't even see our closest neighbour, Proxima Centauri. We see these stars because they have large observational signals, and that illustrates one of the problems in astronomy.

Astronomers Snap a Rare Photo of a Super-Jupiter with Two Suns

If you read enough articles about planets in binary star systems, you’ll realize almost all of them make some sort of reference to Tatooine, the fictional home of Luke Skywalker (and Darth Vader) in the Star War saga. Since that obligatory reference is now out of the way, we can talk about the new “super-Jupiter” that researchers from two separate research teams, including one at Northwestern University and one at the University of Exeter, simultaneously found in old data from the Gemini Planet Imager (GPI).

China's Shenzhou-21's Crew Test New Spacesuits During Spacewalk

The Shenzhou-21 crew on board China's orbiting space station completed its first extravehicular activities on Tuesday, Dec. 9th, during which they validated the new EVA spacesuits.

Uranus and Neptune might be rock giants

A team of researchers from the University of Zurich and the NCCR PlanetS is challenging our understanding of the interior of the Solar System's planets. The composition of Uranus and Neptune, the two outermost planets, might be more rocky and less icy than previously thought.

It Didn't Take Long For Earth's Ancient Oceans To Become Oxygenated

For roughly two billion years of Earth’s early history, the atmosphere contained no oxygen, the essential ingredient required for complex life. Oxygen began building up in the atmosphere during the period known as the Great Oxidation Event (GOE), but it had to enter the oceans first. When and how it first entered the oceans has remained uncertain.

Did a Rogue Planet Reshape Our Solar System?

Researchers have discovered that a close encounter with a rogue planet or brown dwarf during the Sun's early years could have triggered the reshuffling of our Solar System's giant planets. Running 3000 simulations of stellar flybys, the team found that substellar objects passing within 20 astronomical units of the young Sun could destabilise the planets' orbits just enough to match their current configuration without destroying the delicate Kuiper belt. This flyby scenario represents a new possible explanation for one of the Solar System's defining events, with roughly a 1-5 percent probability depending on how common free floating planets actually are in young star clusters.