Friends brought their children over last night for a lunar nerdfest and were rewarded with these views of the Moon.
The upper image shows a curved mountain range crossing the middle portion. The crater Eratosthenes grazes the range at the middle of the image and to its lower left the magnificent crater Copernicus dominates the edge of the image. Between the two craters, tiny craters form an irregular vertical line, the result of debris flung from Copernicus when it was formed by a giant impact. North of the mountains a large lava plain pocked with few craters forms the surface of Mare Imbrium, (the ”Sea of Showers”). Yes, the curved mountain range crossing the image is the rim of Mare Imbrium, a crater so gigantic, it is known as an “impact basin.”
The image on the lower left shows a much smaller impact basin on the left half and the Southern Highlands on the right half. The “Sea of Clouds” is a solidified, lava-filled depression that has very few craters while the highlands to its right is pocked with old, battered carters. This tells us that the “sea” is younger than the highlands.
The third image on the lower right show the bright rays streaking away from two small craters. These are very young craters. All craters had bright rays at one time, but with time they weather away and disappear, in perhaps a billion years. Wow! That really doesn’t seem young, but everything is relative on the Moon. Directly below the younger craters, an ancient impact basin, Mare Australe (the Southern Sea) can be seen along the limb of the Moon. It has remains of a lava floor but has lots of lava-flooded craters. It is much older than Mare Imbrium mentioned above. It is likely around four billion years old! Wow, that is ancient.
Now I don’t feel so bad when I look in the mirror…