Here are 5 bogus alien theories to disappoint your X-Files loving friends

A recent study claims to have found evidence for mushroom-like life forms on the surface of Mars. As it happens, these particular features are well known and were discovered by cameras aboard Nasa’s Mars Exploration Rover Opportunity, shortly after it landed in 2004.

They are not, in fact, living organisms at all, but “haematite concretions” – small sphere-shaped pieces of the mineral haematite, and their exact origin is still debated by scientists. Haematite is a compound of iron and oxygen and is commercially important on Earth. The spherical rocks on Mars may have been created by the gradual accumulation of the material in slowly evaporating liquid water environments. They could also have been produced by volcanic activity.

Either way, mushrooms they are not. The area around Opportunity’s landing site is littered with them – they can be seen all over the surface and were also found buried beneath the soil and even embedded within rocks.

Fossilized worms

These space “mushrooms” were not the first claim of alien life. On August 7, 1996, the then US president Bill Clinton stood on the White House lawn and announced the possibility that scientists had discovered the ancient, fossilized remains of micro-organisms in a meteorite that had been recovered from Antarctica in 1984.

The meteorite, ALH 84001, is one of a handful of rocks we have from Mars. These were blasted off the surface of the planet by volcanic eruptions or meteorite impacts, drifted through space probably for millions of years, before ending up on Earth.