ALBUFEIRA

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The Far Side of The Moon – And Wall The Way Around

The lunar farside as never seen before!

Because the moon is tidally locked (meaning the same side always faces Earth), it was not until 1959 that the farside was first imaged by the Soviet Luna 3 spacecraft (hence the Russian names for prominent farside features, such as Mare Moscoviense). And what a surprise -­ unlike the widespread maria on the nearside, basaltic volcanism was restricted to a relatively few, smaller regions on the farside, and the battered highlands crust dominated. A different world from what we saw from Earth.

Of course, the cause of the farside/nearside asymmetry is an interesting scientific question. Past studies have shown that the crust on the farside is thicker, likely making it more difficult for magmas to erupt on the surface, limiting the amount of farside mare basalts. Why is the farside crust thicker? That is still up for debate, and in fact several presentations at this week's Lunar and Planetary Science Conference attempt to answer this question.

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The first views ever of the far side of the Moon

First view ever of the far side of the Moon

Russia's Luna 3 spacecraft returned the first views ever of the far side of the Moon. The first image was taken at 03:30 UT on 7 October at a distance of 63,500 km after Luna 3 had passed the Moon and looked back at the sunlit far side. The last image was taken 40 minutes later from 66,700 km. A total of 29 photographs were taken, covering 70% of the far side. The photographs were very noisy and of low resolution, but many features could be recognized. This is the first image returned by Luna 3, taken by the wide-angle lens, it showed the far side of the Moon was very different from the near side, most noticeably in its lack of lunar maria (the dark areas). The right three-quarters of the disk are the far side. The dark spot at upper right is Mare Moscoviense, the dark area at lower left is Mare Smythii. The small dark circle at lower right with the white dot in the center is the crater Tsiolkovskiy and its central peak. The Moon is 3475 km in diameter and north is up in this image.

NASA