December 13, 2016
It’s a hell of a lot more expensive to stick a telescope in orbit than it is to build one down here on Earth, so space agencies tend to build more of them. But there’s one challenge all these terrestrial telescopes have to deal with: the atmosphere. All that air distorts light coming in from stars and galaxies. The last thing you want as an astronomer is a bunch of twinkling stars. That’s where lasers come in.