Why there are no stars in American photos of the Moon

All NASA astronauts landed on the Moon during the day, when it was too bright to see stars with the naked eye, and they didn't intend to take pictures of the stars.

If you have ever seen old films and photos of Apollo astronauts walking on the Moon, you will see that most of them lack stars in the sky. This makes many people doubt the authenticity of the Apollo program that NASA carried out during the period of 1961 - 1972.

Astronaut Buzz Aldrin stands on the surface of the Moon, with no stars in the background. (Photo: NASA).

Part of the reason is that all the astronauts landed during the day on the Moon (a day on the Moon is about 14 Earth days long), when it's too bright to see the stars with the naked eye.

"We have never seen stars from the surface of the Moon or from the bright side of the Moon (the side that always faces Earth) with the naked eye without using optical instruments ," US astronaut Neil Armstrong said at a press conference. Astronaut Buzz Aldrin agreed: "I don't remember ever seeing any stars."

But stars can be seen from the surface of the Moon with optical instruments. They are even less blurry than they are from Earth, where the atmosphere bends light. So why don't the stars show up in other photos? It 's a photographic problem, not a space problem.

The Apollo astronauts were primarily interested in photographing the surface of the Moon, and they were standing on it. So they used fast shutter speeds and small apertures to photograph the illuminated surface and themselves. As a result, there are no stars in the background, just as people don't see stars in photos of themselves on Earth.

Earth and stars taken from the Moon. (Photo: NASA).

The only exception was the Apollo 16 mission, when the crew carried the Far Ultraviolet Camera/Spectrograph . "The telescope on the Moon studied many star clusters as well as nebulae—clouds of gas and dust where new stars form ," explains NASA's Tricia Talbert.

"The astronauts also pointed the telescope at the Large Magellanic Cloud, a small galaxy orbiting the Milky Way. It's called the Camera/Spectrometer because it has two modes of operation: "Live Imaging," which takes pictures like those from a regular camera, and "Spectrography," a way of splitting light to look for traces of atoms and molecules in astronomical objects ," Talbert added.

Thanks to this first telescope on the Moon, the Apollo 16 crew captured images of the stars, and Earth, from the lunar surface.

During the Apollo 11 mission in 1969, when the first astronauts walked on the starless moon, astronaut Michael Collins sat alone in the spacecraft's command module, flying behind the dark side of the moon. There, though completely cut off from human contact, he could at least take in a spectacular view.

"I felt, not afraid or lonely, but extremely expectant, content, confident, almost elated. I liked the feeling. Out the window I could see the stars, that was all. Where I knew the Moon was, there was only darkness. I could only tell that the Moon was there by the absence of the stars," Collins wrote in his 1974 book Carrying The Fire .