Add Yahoo as a preferred source to see more of our stories on Google. A composite view of Mars taken by the Viking I and II probes. NASA/USGS In September, NASA announced the discovery of a possible ...

For decades, astronomers have chased fleeting hints that something alive might be lurking beyond Earth, only to watch each candidate fade under scrutiny. Now a distant world called K2-18 b has ...

The afternoon of 7 August 1996 isn’t a time that sticks in many people’s minds. But if things had worked out differently, it might have been etched into our collective memory. At 1.15pm, US President ...