Astronomy

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.

Our understanding of the true nature of the cosmos relies on measurements of its expansion, but cosmologists have been arguing back and forth about it for more than 100 years

Our understanding of the true nature of the cosmos relies on measurements of its expansion, but cosmologists have been arguing back and forth about it for more than 100 years

The combination of a supernova and a kilonova may have produced a rare space explosion that astronomers have never seen before

A scientist, a journalist and a remarkable scent‑detecting dog race to learn what’s endangering the last southern resident orcas

On 17 December, two Galileo satellites lifted off from Europe’s Spaceport in French Guiana aboard an Ariane 6 rocket. This marked the 14th launch for Europe’s Galileo constellation, reinforcing Europe’s satellite navigation capabilities, resilience and autonomy. 

Video: 00:01:06

On 17 December, two new Galileo satellites lifted off from Europe’s Spaceport in French Guiana aboard an Ariane 6 rocket. This marked the 14th launch for Europe’s satellite navigation operational satellite programme, reinforcing Europe’s resilience and autonomy.

The European Space Agency (ESA) is responsible for carrying out the Galileo launch with Arianespace on behalf of the European Commission. The Galileo satellites were manufactured by OHB, under contract with ESA. Once in orbit, the EU Agency for the Space Programme (EUSPA) will bring the satellites into service and oversee their operation.

The flight, designated VA266, was the first launch of Galileo satellites on Europe’s newest heavy-lift launcher Ariane 6.

Follow the launch campaign. 

Access the related broadcast quality video material. 

Bones of now extinct species became a haven for bee babies thousands of years ago, scientists report in a first-of-its-kind discovery

Where does the Sun end and the solar wind begin? Scientists have mapped the dynamic magnetic edge that bounds our star.

The post Scientists Map the Sun’s Magnetic “Surface” appeared first on Sky & Telescope.

Clockwise from left, JAXA (Japan Aerospace Exploration Agency) astronaut Kimiya Yui and NASA astronauts Jonny Kim, Zena Cardman, and Mike Fincke pose for a playful portrait through a circular opening in a hatch thermal cover aboard the International Space Station on Sept. 18, 2025.

The Arctic has changed dramatically in the past 20 years, a new report shows, as temperatures skyrocket and ice rapidly melts

A novel influenza variant called subclade K appears to be driving an uptick in cases and hospitalizations throughout the U.S. and other countries

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.

Sculpted by stellar winds and radiation, this dusty interstellar

President Donald Trump is expected to sign a defense bill this week that orders an investigation into whether the U.S. military bioengineered Lyme disease

The Large-Scale Structure of the Universe features massive filaments where galaxy clusters and superclusters reside. In between these filaments are cosmic voids, vast regions that are nearly empty. The Nancy Grace Roman will map and study 80,000 of these voids to place constraints on Dark Energy drives the expansion of the Universe.

Copernicus Sentinel-6B, launched last month, has reached its orbit and delivered its first set of data, which show variations in sea level in the North Atlantic Ocean. This data underlines how the mission will continue to strengthen the long-term reference record of sea levels, a key parameter of climate change.

New laboratory studies could shed light on a rock containing potential signs of alien life that’s stranded on Mars

Sort out a rectangle tangle in this math puzzle

This week marks the last chance for backyard astronomers to see interstellar Comet 3I/ATLAS before it races on its journey back to outer space