La Terra vista dalla Luna 45 anni fa: genesi di una foto storica

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Forty-five years ago, Apollo 8 astronauts Frank Borman, Jim Lovell, and Bill Anders became the first humans to orbit the Moon, and the first to witness the magnificent sight called "Earthrise." Now, for the first time, we can see this historic event exactly as the astronauts saw it, thanks to new data from NASA's Lunar Reconnaissance Orbiter, or LRO. LRO's superb global lunar maps, combined with the astronauts' own photographs, reveal where Apollo 8 was over the Moon, and even its precise orientation in space, when the astronauts first saw the Earth rising above the Moon's barren horizon.

On December 24, 1968, a few minutes after 10:30 am Houston time, Apollo 8 was coming around from the far side of the Moon for the fourth time. Mission Commander Frank Borman was in the left-hand seat, preparing to turn the spacecraft to a new orientation according to the flight plan. Navigator Jim Lovell was in the spacecraft's lower equipment bay, about to make sightings on lunar landmarks with the onboard sextant, and Bill Anders was in the right-hand seat, observing the Moon through his side window, and taking pictures with a Hasselblad still camera, fitted with a 250-mm telephoto lens. Meanwhile, a second Hasselblad with an 80-mm lens was mounted in Borman's front-facing window, the so-called rendezvous window, photographing the Moon on an automatic timer: a new picture every twenty seconds. These photographs, matched with LRO's high-resolution terrain maps, show that Borman was still turning Apollo 8 when the Earth appeared. It was only because of the timing of this rotation that the Earthrise, which had happened on Apollo 8's three previous orbits, but was unseen by the astronauts, now came into view in Bill Anders's side window. Here's what it looked like, as recreated from LRO data by Goddard's Scientific Visualization Studio. You'll hear the astronauts' voices as captured by Apollo 8's onboard tape recorder, beginning with Frank Borman announcing the start of the roll maneuver, and you'll see the rising Earth move from one window to another as Apollo 8 turns.

Borman: All right, we're gonna roll. Ready… Set…

Anders: The impact crater with uh - at uh - just prior to the subsolar point on the south side, in the floor of it, uh, [unintelligible], there is one dark hole. But I couldn't get a quick enough look at it to see if it might be anything volcanic.

Anders: Oh my God, look at that picture over there! There's the Earth comin' up. Wow, is that pretty!

Borman: Hey don't take that, it's not scheduled.

[shutter click]

Anders: You got a color film, Jim? Hand me a roll of color, quick, would you?

Lovell: Oh man, that's great.

Anders: Hurry.

Lovell: Where is it?

Anders: Quick

Lovell: Down here?

Anders: Just grab me a color. A color exterior. Hurry up. Got one?

Lovell: Yeah, I'm looking' for one. C 368.

Anders: Anything. Quick.

Lovell: Here.

Anders: Well, I think we missed it.

Lovell: Hey, I got it right here [in the hatch window].

Anders: Let me get it out this one, it's a lot clearer.

Lovell: Bill, I got it framed, it's very clear right here!

[shutter click]

Lovell: Got it?

Anders: Yep.

Lovell: Take several, take several of 'em! Here, give it to me!

Anders: Wait a minute, just let me get the right setting here now, just calm down.

Lovell: Take -

Anders: Calm down, Lovell!

Lovell: Well, I got it right - aw, that's a beautiful shot…Two-fifty at f/11.

[shutter click]

Anders: Okay.

Lovell: Now vary-vary the exposure a little bit.

Anders: I did, I took two of 'em here.

Lovell: You sure you got it now?

Anders: Yeah, we'll get - well, it'll come up again, I think.

For the astronauts, seeing the Earthrise was an unexpected and electrifying experience, and one of the three photographs taken by Bill Anders became an iconic image of the 20th century. But as we've just seen and heard, that photograph was actually a group effort: not just because Jim Lovell found the roll of color film and gave it to Anders, but because the astronauts wouldn't have seen the Earth if Frank Borman hadn't been turning the spacecraft just as it was coming up. Today, the Earthrise has become a symbol of one of history's greatest explorations, when humans first journeyed to another world and then, looking back, saw their home planet, in Lovell's words, as a grand oasis in the vastness of space. I'm Andrew Chaikin, author of "A Man on the Moon." [ music ]