NASA’s GRAIL sheds light on Moon’s geology
What does a 3.8 billion-year-old crater have in common with data from a pair of spacecraft that crashed into the Moon nearly four years ago? Both are helping to provide clues about the geology of Earth’s natural satellite.
Though the Moon may be Earth’s nearest neighbor in space, that doesn’t mean it has long since given up its secrets. NASA’s Gravity Recovery and Interior Laboratory (GRAIL) twin spacecraft orbited the Moon for nearly a year, collecting a wealth of gravitational field data, before impacting the Moon’s surface on December 17, 2012.
Researchers have been poring over the data collected from 1.2 miles (2 kilometers) above the enormous Mare Orientale impact basin, and have published two papers in the journal Science this week – one focusing on understanding the structures of large impacts, and the other detailing how Orientale formed and applying that information to create simulations accurately portraying the formation of the basin.
Of particular interest was the structure of the crater itself. With smaller impacts, “classic” bowl-shaped craters are formed. However, larger collisions create a markedly different formation – wide, flat basins, often with multiple walls or rings. It had been theorized that the rings in Orientale were remnants of the initial impact.
Read much more in my full piece at SpaceFlight Insider…