Using Earth-based Radar To Look Under The Moon’s Surface
As the public prepares for the upcoming eclipse, astronomers have released a striking new radar view of the Moon.
Image: Southeastern Lunar highlands. Image courtesy Bruce A. Campbell, Smithsonian’s Air and Space Museum, GBT Green Bank Observatory/AUI/NSF, Arecibo Observatory. The Green Bank Observatory is a facility of the National Science Foundation operated by Associated Universities, Inc., under a cooperative agreement with the National Science Foundation. Planetary radar at Arecibo is funded by the NASA Near-Earth Object Observations program managed by USRA.
Researchers from the Smithsonian’s National Air and Space Museum are using radio telescopes at the Arecibo Observatory and Green Bank Observatory to map the Moon with radar. The radar signals, transmitted from the Arecibo telescope and received at the Robert C. Byrd Green Bank Telescope, can probe many meters below the surface of the Moon, just like ground-piercing radar on Earth. They reveal Lunar structures that can’t be seen in optical images because they’re hidden from view under the layer of dust and rubble that covers the Moon’s surface. The scientists are searching for unseen structures of Lunar geology such as lava flow complexes and buried craters.
This is a radar view of the Moon’s southeastern highlands, showing the densely cratered surface formed as the result of more than 4 billion years of meteorite impacts. The radar can distinguish the age of some craters. Younger impact craters have enhanced radar return showing bright floors and surrounding areas due to rocky material that has not yet been worn away by very small meteorites.
In this image North is up, and the bright crater at the upper right is Theophilus. The dark ring in the image is due to the pattern formed by the transmitting and receiving antennas.
