A pair of NASA spacecrafts have recently found evidence that the moon and some planets in the sun’s solar system were hit by a series of intense impacts. Although scientists knew these rocky bodies had been hit in the past, the new findings have revealed that the impart may have been much more violent than previously found.
The new findings were made by the Grail probes, a twin set of probes from NASA. The probed have developed an extremely detailed gravity map of the moon, which has shown that the crust is almost completely gone. Scientists this may be due to ** billions of years ago. Although studies have not been done yet, these findings suggest that Earth, Mercury, Venus, and Mars may have gone though a similar ordeal.
Maria Zuber, a professor at MIT and the lead scientist on the Grail project, recently gave a press release about the probes’s findings at the annual American Geophysical Union meeting on Wednesday. At the meeting, she announced that the findings “really opens a window to this early stage of just what a violent place the surfaces of all terrestrial planets were early in their history.”
The moon is “far more broken up and shattered than we’ve seen before,” she noted.
According to Zuber, the Grail probe findings will help reveal how the moon was formed. In addition, she expects the project to help scientists understand where life could have existed on Mars before and where it may exist today.
The twin Grail probes, named Ebb and Flow, were sent to space in September 2011 with the mission to create an extremely precise map of the gravitational field of the moon. Together, the probes fly around the moon detecting small differences in the distance they are apart, which is causes by lunar mountains, craters, and subsurface mass concentrations.
As the probes circle the moon, they take measurements that are sent to the scientists leading the project. The measurements are then used to develop an extremely high resolution gravitational field map of the moon. According to the research team, a map of this resolution has never been created for any celestial body before.
After several months of measurements, the Grail probes have found that the crust of the Moon has many holes, which has led the team to believe the planet was bombarded with impacts billions of years ago. The probes have also determined that the crust of the moon is just 21 to 27 miles (34 to 43 km) thick, which is much thinner than previous estimates of 30 to 40 miles, or 48 to 64 km.
Even though the Grail probes finished their original mission in May, they are currently still in orbit, this time until mid-December. The results presented by Zuber were only from the primary mission. Currently they are circling even closer to the surface of the moon in an effort to improve to make the resolution of the map even better. Once Ebb and Flow’s extended mission is over, they will be hurled into the moon intentionally.