Astronomy

Ask someone on Earth for the time and they can give you an exact answer, thanks to our planet's intricate timekeeping system, built with atomic clocks, GPS satellites and high-speed telecommunications networks. Ask for the time on Mars and the answer gets much more complicated.

We greet the winter solstice. Jupiter nears opposition. Will the two Dog Stars balance for you? And meet the House in the Hyades.

The post This Week's Sky at a Glance, December 19 – 28 appeared first on Sky & Telescope.

From massive solar panels to the difficulty of staying cool - not to mention high-energy radiation - there are a lot of engineering problems that need to be solved before we can build data centres in space

From massive solar panels to the difficulty of staying cool - not to mention high-energy radiation - there are a lot of engineering problems that need to be solved before we can build data centres in space

Week in images: 15-19 December 2025

Discover our week through the lens

After starting the year with its first known bird flu death, the US expanded its efforts to contain the virus, which enabled it to end its public health emergency response months later

After starting the year with its first known bird flu death, the US expanded its efforts to contain the virus, which enabled it to end its public health emergency response months later

Rapid advances in the kind of problems that quantum computers can tackle suggest that they are closer than ever to becoming useful tools of scientific discovery

Rapid advances in the kind of problems that quantum computers can tackle suggest that they are closer than ever to becoming useful tools of scientific discovery

NASA’s newest space telescope has unveiled a stunning map of the cosmos in infrared

Getting close to things is one way for scientists to collect better data about them. But that's been hard to do for the Sun, since getting close to it typically entails getting burnt to a crisp. Just ask Icarus. But if Icarus had survived his close encounter with the Sun, he might have been able to see massive magnetic “tadpoles” tens of thousands of kilometers wide reconnecting back down to the surface of our star. Or maybe not, because he had human eyes, not the exceptionally sensitive Wide-Field imagers the Parker Solar Probe used to look at the Sun while it made its closest ever pass to our closest star. A new paper in The Astrophysical Journal Letters from Angelos Vourlidas of Johns Hopkins University’s Applied Physics Laboratory and his co-authors describes what they say on humanity’s closest brush with the Sun so far.

Hidden Fibonacci numbers, a new shape and the search for a grand unified theory of mathematics are among our choices for most exciting findings of the year

Depending on how you look at it, this catchphrase from a 1980s pop song is decently accurate: you can actually melt the planet if you stop its turning

New laws in the UK, Australia and France were brought in during 2025 with the aim of protecting children from harmful content online, but experts remain divided on whether they will achieve this goal

New laws in the UK, Australia and France were brought in during 2025 with the aim of protecting children from harmful content online, but experts remain divided on whether they will achieve this goal

It's easy to assume that the most talented adults among us were once gifted children, but it turns out that talent during childhood is no guide to later success

It's easy to assume that the most talented adults among us were once gifted children, but it turns out that talent during childhood is no guide to later success

Researchers uncover 20 new underwater calls from Hawaii’s endangered monk seals.

Image: This week Earth from Space features a wintery image: a red and white sphere that, if seen from a distance, resembles a festive decoration.

Image: Dwarf stars in a glittering sky