Lunar Day Seven

  • Tammy PlotnerEmail author
Part of the Astronomer’s Pocket Field Guide book series (ASTROPOC)


Tonight we will begin our lunar explorations as we look to the far north and explore the “Sea of Cold” - Mare Frigoris (Figs. 8.1 and 8.2). This long, vast lava plain extends 1,126 km across the surface from east to west, yet never ranges more than 72 km from north to south. Look for the unmistakable dark ellipse of landmark crater Plato caught on Frigoris’ southern central shore. Named after the famous philosopher, this Class V crater spans approximately 101 km but is a shallow 1 km deep. The bright rim of Plato’s enclosure is very ragged and can rise as high as 2 km above the surface, casting unusual shadows on the lava covered floor. At around 3 million years old, Plato is more ancient than Mare Imbrium to its south. For 300 years astronomers have been keeping a watchful eye on this crater. Hevelius called it the “Greater Black Lake,” because of its low albedo (surface reflectivity). Despite its dark appearance, Plato is well known as a home for lunar transient phenomena such as flashes of light, unusual color patterns, and areas that could be outgassing. Enjoy this lunar feature which will point the way to others in the future! We will be back to look again on Lunar Day Twenty…


Central Peak Lunar Surface West Wall Lunar Prospector Lunar Exploration 
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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  1. 1.CaledoniaUSA

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