The Gemini Observatory in Hawaii caught this first-ever color image of the interstellar comet Borisov and its faint tail. (Credit:Composite image by Travis Rector. Credit: Gemini Observatory/NSF/AURA)

Asteroids, comets and other rocky objects litter the solar system, left over from when the planets formed. Scientists study these space rocks to learn about what the early solar system was like. Now, we’re entering an era in which we can learn about alien planetary systems in the same way, than