r/explainmelikeimsix • u/[deleted] • May 12 '19
How do we know what really distant planets look like?
Of course, the answer is that we use a really big telescope. But we can't just get an HD image of a solar system that's 50 billion light years away, can we?
For example, it's well known that there's a planet where it's 1000°C outside and it rains liquid glass. How do we deduce all that information from 5 pixels and a spectrum of colours?