At 4:17 PM Eastern Time on July 20, 1969, the Eagle landed on the Sea of Tranquility.

Armstrong’s voice, calm and quiet: “Houston, Tranquility Base here. The Eagle has landed.”

I was sitting in my living room. Betty was next to me. Harold was in the armchair. Edna was on the couch. Nobody in the room was breathing correctly.

When Charlie Duke’s voice at Mission Control said, “Roger, Tranquility. We copy you on the ground. You’ve got a bunch of guys about to turn blue. We’re breathing again. Thanks a lot,” I heard Betty cry softly beside me and I didn’t try to pretend my eyes were dry.

Two men are on the Moon.

I need to sit with that for a moment before I write any more.

Two men are on the Moon. Neil Armstrong and Buzz Aldrin are standing in the Eagle lunar module on the surface of the Sea of Tranquility, on the Moon, 238,900 miles from the chair I’m sitting in. They flew there. They descended through twelve minutes of powered flight, with three guidance computer alarms and Armstrong manually flying the last hundred feet to avoid a boulder-filled crater. The contact light illuminated and Armstrong shut down the engine and the Eagle settled onto four landing legs in a shallow depression in the regolith.

Settled. Just like that. Like it always lands. Like it was the most ordinary thing in the world to fly to the Moon.

The fuel situation during the descent was tight. They had about 20 seconds of fuel remaining when they touched down. Twenty seconds. If they’d aborted that late, the abort might not have worked cleanly. The margin was razor-thin and Armstrong knew it and flew it anyway.

He is 38 years old and he just landed on the Moon with 20 seconds of fuel to spare.

I keep starting sentences and not finishing them because there are too many things to say and none of them are adequate. I’ve been following this program since 1957. Since the beep. Since Laika. Since Gagarin. Since Kennedy. Since the fire. Twelve years.

They’re on the Moon.

It worked.