Stars in Space Images

[Bullgrit]

I just looked at this new image from space, and it brings up a question I've had for decades:

Why are there no stars in photographs from space?

I first noticed this when I was very young, looking at the images taken by the moon astronauts in the late 60s. Why do stars not show up in photographs from space?

Bullgrit
Total Bullgrit

 

[kenobi65]

My guess is exposure time. Stars are (comparatively) very, very dim; to get them to show up on photographs, you'd need a very long exposure -- which'd likely totally wash out the subject of the photo, if the subject isn't a star itself.

Most of those photographs you're probably thinking of are either of the Earth or space vehicles, or taken on the surface of the Moon. In all of those cases, the primary subject of the photograph is well-lit by sunlight, and so, the exposure time on the photograph is likely very short -- not nearly long enough for the dim light of the stars in the background to register.

OTOH, actual photos of stars (as opposed to a photo of the Earth, in which you might have stars in the background) usually have to be taken with *very* long exposures, so that the film can actually accumulate enough light from the stars to register.

 

[Umbran]

As I understand the photography, kenobi65 has the right idea. Short exposure times used to image bright, nearby objects don't usually catch comparatively dim stars.

 

[Kmart Kommando]

you get the same effect using a flash in low light. the brightly-lit subject is seen, but the background is washed out.

 

[trancejeremy]

Yeah, you need to do a time-exposure to take photos of stars, even with CCDs/Digital cameras, and then a thing that rotates the camera/telescope (or compensate for the moment in CCD cases), otherwise you get star trails.

Same principle here - it had to be a short photo, because otherwise the Earth would move, too short to get enough light from the stars to show up.

 

[Steve Jung]

Which is why it's funny that moon landing deniers regard not seeing stars in Apollo mission photos as one of their pieces of evidence.

 

[Bullgrit]

Thanks, guys, for clearing up something that has been a mystery to me for over 30 years.

Bullgrit
Total Bullgrit

 

[Angel Tarragon]

Wow, albeit small, that is a great image.