The prospect that life did once exist, still exists and could be sustained in the future on Mars has taken a huge step forward with the confirmation that water ice has been found on the planet.

"We basically have found what appears to be the requirements, the nutrients, to support life whether past present or future," Sam Kounaves, the lead investigator for the wet chemistry laboratory on Phoenix, told journalists.

"It is the type of soil you would probably have in your back yard, you know, alkaline. You might be able to grow asparagus in it really well. ... It is very exciting for us."