Eyecatchers-45 : 'Man in the Moon' is four billion years old - AFP

The plains of solidified lava that give the moon its quirky human-like face as seen from the earth were created more than four billion years ago, according to a paper appearing on Thursday, in NATURE, the British science weekly.

The evidence comes from an unearthly silvery-grey stone that was blasted off from the face of the moon, perhaps by an impacting asteroid, and was the captured by the earth’s gravity, prompting to fall to ground in Botswana.

In 1999, the 13.5 kg remnant of this roving rock was found by local people near the village of Kuke, in the grasslands of the sprawling Kalahari Nature Reserve, who then sold it to meteorite hunters.

The lunar heritage of the rock, named Kalahari 009, has been confirmed by a telltale signature of oxygen isotopes and ratio of iron to manganese in two volcanic minerals, olivine and pyroxene.

The nature of these chemicals puts the rock into the category of a mare basalt – a lava that flowed out smoothly onto the lunar surface before solidifying, forming dark plains that early skywatchers mistakenly took for seas, “Mare” in Latin.

New analysis

A new analysis of fragments of phosphate in Kalahari 009 puts the rocks at the whopping old age of 4.35 billion years, give or take 150 million years, the Nature study says.

This implies that mare-type volcanism must have occurred at least as early as this date, just after the first stage of lunar crust formation, say the authors, led by Kentaro Terada of Hiroshima University in Japan and Mahesh Anand of Britain’s Open University.

Mare volcanism overlapped with a later stage of volcanism, evidence of which was found in rocks picked up by the Apollo missions.

The ‘Man in the Moon’ comprises eyes made of the Mare Imbrium and Mare Serenitatis, a nose consisting of Sinus Aestuum, while the Mare Nubium and Mare Cognitum provide its mouth. These and other mare account for nearly a sixth of the lunar surface, mostly on the side visible from the earth – AFP

Courtesy: The Hindu, Madurai, December 6, 2007.

Grateful thanks to The Hindu.