NASA landed the first man on the Moon in the evening hours of July 20, 1969, 50 years ago. The incredible mission saw three American astronauts carry out the greatest exploration trip in human history. The mission, which began on July 16, 1969, blasted off from Florida’s Cape Canaveral on an eight-day-long round trip. And through this entire journey, NASA kept a detailed travel log of everything that happened to the Apollo 11 crew.
On the fourth day of the journey, approximately 71 hours and 31 minutes into spaceflight, the three astronauts witnessed the Sun pass behind the Moon.
The incredible incident, described by Edwin “Buzz” Aldrin as “eerie” occurred just 11,232 nautical miles (20,802km) from the Moon.
At 71 hours and 33 minutes, Aldrin buzzed NASA’s Mission Control to find out how best to photograph the astronomical event.
The three astronauts were armed with Hasselblad film cameras to document their journey.
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The Lunar Module Pilot said: “What sort of settings could you recommend for that solar corona?
“We’ve got the Sun right behind the edge of the Moon now.
“It’s quite an eerie sight. There is a very marked three-dimensional aspect of having the Sun’s corona from behind the Moon the way it is.
“And it looks as though – I guess what’s giving it that three-dimensional effect, the Earthshine.
“I can see Tycho fairly clearly – at least if I’m right-side-up, I believe it’s Tycho in Moonshine – I mean, in Earthshine.
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“And, of course, I can see the sky is lit all the way around the Moon, even on the limb of it where there’s no Earthshine or sunshine.”
Tycho is one of the biggest and most prominent impact craters on the surface of the Moon.
The crater sits on the southern lunar highlands and at 53-miles-wide (85km) is one of the Moon’s brightest features.
In order to snap the disappearing Sun behind the Moon, NASA ordered the astronauts to use black and white film.
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Astronaut Bruce McCandless, who was communicating with Apollo 11, said: “Roger. If you’d like to take some pictures, we recommend using magazine Uniform which is loaded with high speed black and white film, interior lights off, electric Hasselblad with the 80-millimetre lens.
“And you’re going to have to hand-hold this, I guess.
“We’re recommending an f-stop of 2.8, and we’d like to get a sequence of time exposures. Over.”
The astronaut then suggested the astronauts photograph the event for an eighth of a second and half-a-second as well as longer, two-second, four-second and eight-second exposures.
The resulting black and white photos reveal a slight sliver of light behind the Moon’s curve – the glowing corona of the Sun behind the Earth’s lunar companion.