SEEING A DIFFERENT SIDE OF OUR CLOSEST NEIGHBOR
Image Credit & Copyright: NASA Lunar Reconnaissance Orbiter (LRO). CLICK photo for larger view and look below for information and links.
This is NASA’s Astronomy Picture Of the Day “APOD” and hopefully most of us recognize this as the far side of the Moon. Not the dark side….remember the far side of the Moon gets just as much light as the near side that we see. So there IS a dark side but it’s wherever it happens to be in its lunar cycle. Just like Earth has a dark side….called night. The big difference is that lunar days and nights last 14 days. You may think that planetary bodies tidally locked like the Earth/Moon system are a rare commodity but in fact almost all moons in the solar system are tidally locked to their planets and only ever show one face to them. Probably the most striking difference from the near to the far side of the moon is that the near side is 31% mares (seas) while the far side is only about 1% mares (seas). We’re of course talking about the great dark regions that we see from Earth, not actual seas.
Let’s check out some features! The first crater to jump out at you in in the upper left quadrant is Mare Moscoviense or Sea of Moscow. Its obvious deep gray interior stands out well against the rest of the surface. The tiny crater within it at the upper right is Titov crater, named after cosmonaut Gherman Titov, the second human to orbit the Earth. The slightly larger crater below it (still within Mare Moscoviense) is Komarov crater, named for cosmonaut Vladimir Komarov who was killed upon impact after reentry during the Soyuz 1 mission.
If you look down and slightly left of Mare Moscoviense you will see another deep gray crater named Tsiolkovskiy crater which is named after Konstantin Tsiolkovsky; a Soviet rocket scientist and along with Oberth and Goddard is one of the founding fathers of rocketry. Apollo 17 astronaut Jack Schmidt (the only scientist on the Moon) strongly advocated this crater as the landing site for Apollo 17. Just to the right of that (slightly larger and light gray) is Gagarin crater, named of course for Yuri Gagarin.
Let’s shift our eyes not to the South Pole region where you will notice that the area is slightly darker that most of the far side. This area is called the South Pole-Aiken basin and it’s a huge impact crater approximately 1600 miles across. It’s one of the largest impact craters in the solar system and its southern rim, called the “Leibnitz Mountains” can sometimes be seen from Earth. Within this basin you will find craters bearing the names of many popular scientists like Schrodinger, Von Karman, Oppenheimer etc. There is also Apollo crater to the right hand side of the basin; a large double ring crater whose rim is largely undefined though it does have a small dark gray patch in its center. Within Apollo crater are smaller craters named for Grissom, White, Chaffee, all seven members of the STS-51-L Challenger disaster as well as all seven members of the STS-107 Columbia tragedy.
Learning the Moon, its regions, Mares (seas) and craters; like learning the constellations, really make the Moon a smaller place. One in which you know your way around very well and when you look up at night, whether it be through a telescope, binoculars or your eyes……you can know just what you’re looking at,
NASA APOD page for this photo: http://apod.nasa.gov/apod/astropix.html
NASA LRO mission page for this photo: http://www.nasa.gov/mission_pages/LRO/news/lro-farside.html
GSFR LRO page: http://lunar.gsfc.nasa.gov/
LROC (LRO’s camera and photo & data collection): http://lroc.sese.asu.edu/n