What advantages does a telescope located outside the earth's atmosphere have over a land-based telescope?
1 Answer
Jan 24, 2015
Because then you don't have to look through all that air.
Above us, there are kilometers of air. Moving air, with different temperatures. You have seen mirages above a hot highway, I think. And there we are only talking about a few hundred meters, or a few kilometers at most. Our atmosphere is a lot thicker than that.
It is really about the equivalent of lying 10 meters deep underwater, and trying to get a picture of what happens above water. And the water is moving...
Because of the air moving at different speeds and at different heights, you get all kinds of refraction. So you never get a steady image.
Also the atmosphere filters out some wavelengths of light, like infrared and some UV.
