Ever wondered why Mars is red? One scientists thinks he knows (and it could happen on Earth, too) - 3rd Apr 2011

(Image) - Surface: Mars is covered with a thin layer of radioactive substances including uranium, thorium and radioactive potassium.

Mars has not always been red.

At least that is the theory proposed by a scientist who has discovered a reason as to how the red planet got its rosy colour.

According to Dr John Brandednberg, about 180 million years ago, a planet-shattering yet naturally occurring nuclear reaction may have wiped out everything on Mars, sending a shockwave that turned the planet into dry sand.

He told Fox News: 'The Martian surface is covered with a thin layer of radioactive substances including uranium, thorium and radioactive potassium - and this pattern radiates from a hot spot on Mars.

'A nuclear explosion could have sent debris all around the planet.

'Maps of gamma rays on Mars show a big red spot that seems like a radiating debris pattern ... on the opposite side of the planet there is another red spot.'

Dr Brandenburg, who is a senior propulsion scientist at Orbital Technologies Corp, said the natural explosion - the equivalent of one million one-megaton hydrogen bombs - occurred in the northern Mare Acidalium region of Mars where there is a heavy concentration of radioactivity.

This explosion also filled the Martian atmosphere with radio-isotopes, which are seen in recent gamma ray spectrometry data taken by NASA, he said.

The radioactivity also explains why the planet looks red. Read More