It still elicits goosebumps: Apollo 8 astronauts Frank Borman, William Anders and James Lovell reading from the Book of Genesis while orbiting the moon on Dec. 24, 1968 — Christmas Eve back home.

“In the beginning God created the heaven and the earth …”

The surprising recitation (NASA’s only instructions to the astronauts: “Do something appropriate”) was watched, live, by the biggest TV audience in history up to that time. “Given the NASA of today it’s absolutely remarkable that they didn’t even check up to see what [Borman] was going to propose doing,” says Anders. “But they knew Frank was a serious guy and would do something right.”

Anders, 85, spoke to The Post about the historic flight, recounted in “Apollo’s Daring Mission,” a NOVA special airing Wednesday (9 p.m. on PBS) to commemorate Apollo 8’s 50th anniversary. Anders, Lovell and Borman were the first men in history to orbit the moon after their initial Earth-orbit-only flight was scrapped amidst space-race panic vis a vis Russia. Anders made more history when he snapped one of the most iconic photographs in history: “Earthrise,” showing the blue-and-green-dappled planet floating in the dark void of space from 239,000 miles away.

“I was the flight engineer and official photographer and had very little photographic training,” Anders says. “I had a 35mm camera when I was a kid … I had no photographic background to speak of and had a very heavy schedule of taking pictures of the lunar surface [for] potential [moon] landing sites.

“We were going around the moon … and after our third revolution, Frank Borman started repositioning the spacecraft so it would be pointing forward,” he says. “I happened to catch something out of the corner of my eye, and here was this beautiful orb that was even more beautiful when compared against the very stark, ugly background of the lunar surface. So I grabbed my camera and started taking pictures. Borman jokingly said, ‘You can’t do that, Anders, it’s not in the flight plan’ — I’d been pretty much holding onto the flight plan because I was overloaded with snapping away at the moon — but I figured, the heck with it, even a coldhearted [Air Force] fighter pilot like me realized this was something worth snapping and lucky for me I had color film and a 250mm lens on my camera.

“It’s certainly not Ansel Adams,” he says of the photo. “I just happened to be in the right place at the right time. I’m proud of it, but I can’t say it was done by a real photographer.”

The astronauts’ wonder at the beauty of the Earth was matched by their first look at the lunar surface. “We were positioned so we basically couldn’t see the moon the whole time from leaving Earth until getting into lunar orbit,” Anders says. “They were worried that just like after an eclipse, we’d get this blast of light and would hurt our eyes. It was until actually just prior to our lunar orbit … we had to slow down to get captured by lunar gravity when we actually first saw the shadows of a lunar sunrise and that was pretty impressive.

“First of all, I thought it was oil running down the spacecraft window,” he says. “I thought, what the hell is that? Turns out it was the long shadows of the mountains on the far side of the moon.”

Anders is asked if, even today, he still looks up at the moon in wonder.

“I remember the night before the launch, we had been in quarantine from our families and [President] Lyndon Johnson invited us to the White House for one last dance,” he says. “I remember sitting with some friends on the hood of my car in the parking lot looking up at the moon, which was just this fingernail sliver that was visible.

“I must say, even today when I look up and see a moon like that with a little sliver, hairs come up on the back of my neck.”