A mosaic image of Enceladus created from data ...

When comet 3I/ATLAS was discovered in July, on a one-way interstellar journey through our Solar System, Harvard astronomer Avi Loeb suggested it might be an alien spacecraft paying us a visit. Back in

We’ve had a few false alarms before – including fossilised microbes and signs of carbon dioxide production in Martian rocks – but NASA has now cautiously suggested it’s found signs that life once exis

One of the most important features of extrasolar planets is whether they have an atmosphere or not. For astrobiology in particular, small, rocky planets blanketed with an atmosphere offer the best hop

We humans are always wondering whether we’re alone in the Universe. But what if we are one of a long line of species that were around long before our planet even existed? This intriguing idea, that li

While our planet only has one easily visible Moon, several other tiny objects arguably deserve the title too