Moon's hidden valley system revealed (BBC)

[eppur_se_muova]

By Jonathan Amos
Science correspondent, BBC News

Scientists have identified a huge rectangular feature on the Moon that is buried just below the surface.

The 2,500km-wide structure is believed to be the remains of old rift valleys that later became filled with lava.

Centred on the Moon's Procellarum region, the feature is really only evident in gravity maps acquired by Nasa's Grail mission in 2012.

But knowing now of its existence, it is possible to trace the giant rectangle's subtle outline even in ordinary photos.

Mare Frigoris, for example, a long-recognised dark stripe on the lunar surface, is evidently an edge to the ancient rift system.
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more: http://www.bbc.com/news/science-environment-29447159

[Ichingcarpenter]

1. I wonder if they could also consist of lava tubes?

which would make great shelters for colonists.

Anyway interesting news