Recently, after hosting the International Space Station (ISS) live feed on our Facebook page, we received quite a few comments pointing out how the footage had to be fake due to the lack of stars in the background.
Now, we could discuss how these people think that the world's governments are running a trillion-dollar scam, and that they alone – commenting on the Internet – have been able to spot the inaccuracies. Or we can admit that everybody is ignorant to varying degrees and that's nothing to be ashamed of, as long as we are actively trying to fight it. So here goes:
Stars are clearly visible in space. Actually, we can see them better from space than through our thick atmosphere. That’s why we keep sending telescopes there.
The reason they are not visible in photos has a lot more to do with photography than with astronomy.
Stars are very dim and the light reflected by the Earth and the Moon is just so much brighter. To take good pictures in space you need to have a high shutter speed and a very short exposure, which means our planet and satellite are clearly visible but the stars often can't be seen.
On top of the unusual light conditions in space, there’s another factor, which requires rapid reaction times from the camera. The ISS moves at 8 kilometers per second (17,150 mph) which is great for staying in orbit but less so for not-shaky images.
The problem is not just an exclusive issue in space, either. Try and take a photo of the night sky on your mobile phone. How many stars do you see? And what happens if you try to take a picture of something in the foreground, do you still see the stars behind?
There’s a reason why astrophotographers use highly expensive equipment that is optimized for the specific task and plan carefully around the hour, weather conditions, and exposure time.
And even if the stars are often not visible in all photos, videos, and live streams, there are plenty of beautifully shot images showing the stars, and even the Milky Way, photographed from the ISS that are available to stare at to your heart's content.
The bright dot among the stars is the planet Venus. NASA/ISS