March 29, 2020

Astro-Event: The Craters of Apollo 11.

The region of the Apollo 11 craters (see below).

Photo by Author.

Recently, we wrote about the “Stars of Apollo 1” and how those astronauts who perished in the fire on Pad 34 were memorialized in the sky by their own hand. This week, we thought we’d draw your attention moonward and bring you next week’s astro-event a few days early to honor the passing of a hero. We’ve wanted to write on the craters named after the Apollo 11 astronauts for some time. Located in the southwestern corner of the Mare Tranquillitatis (The Sea of Tranquility), these three craters named Aldrin, Collins, & Armstrong sit in the general area that Neil Armstrong took his footsteps on the Moon, the first human being to do so on July 20th, 1969. I was busy with my own mission of eating, sleeping and crawling at 11 months of age, but I remember being inspired by the final Apollo missions as a kid. The Sea of Tranquility was selected for its relative safety for the first human landing; Surveyor 5 had landed in the region in 1967, and Rangers 6 & 8 had also impacted the area, with Ranger 8 returning high-resolution pics.

The busy site of Apollo 11 (Credit: NASA/LRO/GSFC/ASU).

Even then, Armstrong had to overfly the region preselected by mission controllers when he noticed that the computer was steering the Eagle towards a boulder field. “(Neil was)…the best pilot I ever knew,” said Apollo co-pilot Buzz Aldrin in a recent statement, landing the Eagle safely with just 25 seconds of fuel remaining. Neil was no stranger to danger, having been a Korean War pilot and later having flown the X-15. I often wonder if it was his cool headedness in bringing Gemini 8 safely back to Earth and ejecting from the LLTV (the “Flying Bedstead” used to simulated lunar landing) that led to his selection as the first man on the Moon.

Neil Armstrong passed away on Saturday, August 25th 2012. Ironically, we have a fitting tribute in the form of two Full Moons this month. Neil was “a nerd’s nerd,” and never sought fame, just the love of science, engineering and exploration. His crater, along with Aldrin and Collins can be found equally spaced just north of the 6.5 km diameter crater Moltke. The crater doublet of Sabine & Ritter on the edge of the Sea of Tranquility serves as a great guide, and in fact, Armstrong crater was known as “Sabine E” until resignation by the IAU. Apollo 10 & 11 also imaged the region from orbit, and the Lunar Reconnaissance Orbiter took a close up photo of the region (much to the chagrin of any would-be Moon landing deniers) showing the legacy of Neil & Buzz on the Moon;

Hardware left on the Moon by Apollo 11. (Credit: NASA/LRO).

Each of these craters are about 4 km across and about 2-3” arc seconds in size. If you can split a 2” double star, you’ll have a shot at spying the Apollo 11 craters at high power. Illumination of the region runs from nine days before until four days after Full Moon, which would mean that the region will be visible during this lunation until September 4th. Right about when the area is along the shadow terminator (i.e. 5 days old, waxing crescent or 15 days old, waning gibbous) is the best time to see the craters of Apollo 11, when long dawn or dusk shadows cause then to stand out in profile.

One of the few pictures of Neil Armstrong on the lunar surface. (Credit: NASA/Aldrin/Apollo 11).

We’d love to see pictures from backyard scopes of the region. 24 men have orbited the Moon, 12 have walked on its surface, 8 of which remain with us today. It’ll be a sad day when no human among us can look skyward to our nearest natural neighbor and state, “I’ve been there; let me tell you what it’s really like…” We owe it to Neil and his legacy to continue the exploration that he started!


  1. David –

    Neil’s death hit me pretty hard — sort of a punch to the chest, as a friend of mine, Dave Michaels said to me, when I conveyed the sorry news to him.

    Space flight was a central part of my childhood, something very vivid and personal, a vibrant part of my very active imagination. But beyond this, I think another part of why this hit me so hard is that this is Something That America Did Right.

    Kennedy literally asked for the Moon, and America delivered.

    Yeah, I’ve been looking up at the Moon when I think of it, and it almost hurts. It’s been nearly a half a century since Armstrong and Aldrin landed, and we haven’t gone back, or gone anywhere else.

    Neil, I’m sorry. America let you down.

    – Daniel

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