The strangely shaped object - snapped by NASA's Opportunity rover - has resurfaced and reignited wild theories about little ...

A rather outlandish claim that an alien gun was spotted in a photo taken on Mars 12 years ago has drawn attention.

A new survey of hundreds of astrobiologists reveals that, despite NASA's high-profile declarations about Mars and exoplanet K2-18b, most experts do not yet think alien life has probably been found.