00:03the moon is one of the greatest constants in the sky however despite being rather dull looking to
00:09the naked eye its surface is chemically pretty wild and now experts say that's likely because
00:14at one point in its history it literally turned inside out using new supercomputer simulations
00:19conducted by nasa researchers have found that likely 4.22 billion years ago the moon's mantle
00:25overturned this all likely had to do with another heating phase that occurred during the moon's
00:29evolution though the cause is still a bit of a mystery one possibility is that the asteroid
00:34which caused the 1550 mile wide south pole eight can basin produced enough heat to jumpstart the
00:40mantles overturn this would have allowed less dense material that was once on the surface to be sucked
00:45down with more dense material ending up above it leading to the strange chemical topography we
00:50observe in a couple of areas on the lunar surface today this new data also suggests that the turnover
00:55occurred very soon after the moon formed only a few hundred million years and this sort of confirms
01:00patterns detected by nasa's gravity recovery and interior laboratory orbiters with the researchers
01:06writing thus the lunar gravity field preserves a critical record of the overturn of the lunar mantle
01:11that has been widely postulated to be one of the defining events in early lunar history but
01:16the details of which have until now remained unknown
