July 20 – Sea of Activity (1969)

Today was a very big day in 1969, as it was the day on which, at 17 minutes past 8 in the evening, Neil Armstrong and Buzz Aldrin (but not Michael Collins) landed their lunar module in the Sea of Tranquility, becoming the first humans in a short line of white, American males to land on the surface of the Moon.

Apollo 11 Crew (image credit: NASA)
Apollo 11 Crew (image credit: NASA)

There has been a great deal written and said about this event, and even more than usual in this 50th anniversary year, with which I won’t attempt to compete. I will just say that although the intrepid moon men brought back 21.5 kg of lunar material, the main impact of their visit from the Moon’s perspective was to leave behind several tonnes of extremely expensive scrap metal.

Tranquility from the window of the Lunar Module (image credit: NASA)
Tranquility from the window of the Lunar Module (image credit: NASA)

The Sea of  Tranquility (Mare Tranquillitatis), once thought to be an ocean on the Moon, is a large basalt basin, probably produced by a lava flow following the impact of something quite large, at the time of the Pre-Nectarian epoch, meaning it was formed before the Mare Nectaris.  The Pre-Nectarian doesn’t really have an equivalent epoch on Earth, because any rocks of a similar age down here would long ago have been sucked back below the surface to be recycled.

Looking towards home from Apollo 11 landing site (image credit: NASA)
Looking towards home from Apollo 11 landing site (image credit: NASA)