After a summer of fasting on land, the bears need to get back to their frozen home to hunt seals and bulk up. But their migration ritual is changing.

Today, we know of Mars as a cold, dry desert, with patches of subterranean ice and ice caps at its poles. Billions of years ...

As Earth approaches warmer levels experienced earlier in its geologic history, it may be bad news for human survival.

Astronomers have identified sulfur as a potentially crucial indicator in narrowing the search for life on other planets. While sulfur itself is not necessarily an indication of habitability, ...

"I'll always remember the first time I saw those iridescent clouds and was sure at first it was some color artifact." ...

The Sun is slowly setting, it is a beautiful clear sky, and I am in the northern Prague district of Ďáblice inside a long wooded park called Ďáblický háj, which is approximately 60 hectares in size.

NASA researchers have identified geological structures on Mars that are unlike anything found on Earth. From spider-like ...