A return mission to the moon offers the best hope of understanding life on Earth and discovering whether alien life lurks in distant corners of the universe, according to a British scientist.
Ian Crawford, a planetary scientist at University College London, will today call for the first crewed missions to our nearest celestial neighbour in more than three decades. Speaking at a meeting of the UK's Astrobiology Society at the University of Kent, Dr Crawford will outline how clues to the existence of life in the solar system and beyond may be locked in rocks and debris that crashed on to the moon and were preserved on the sterile surface.
"There's a perception that when it comes to the moon, we've been there, done that. But the Apollo missions landed more than 30 years ago and didn't really scrape the surface, either literally or figuratively," he said. "The moon has been orbiting the Earth ever since the two formed, and since then it's been there as a silent witness to everything that's happened in Earth's entire history."
It is the moon's lack of life, atmosphere and geological activity, such as volcanoes or shifting continental plates, that makes it such a good place to look for signs of life.
In the early years of the solar system, meteorites and comets crashed into planets, sending vast clumps of rock into space. Some of the rocks crashed into active planets such as Earth, but eroded away. Those that landed on the moon are likely to be preserved, holding inside them evidence about fledgling life forms or the environments they lived in.
"The Earth is about 4.5bn years old, but the earliest fossils we've found date back to around 3.5bn years. The problem is we don't have rocks much older than that because they've eroded away, so we don't know if life on Earth began earlier," said Dr Crawford.
The Bush administration plans to return to the moon to reinvigorate the US space agency, Nasa, but the plans foresee the creation of a moon base to be used primarily as a staging post ahead of a crewed mission to Mars.
Written by Ian Sample
Source: The Guardian, April 19, 2006