Is there any proof of oxygen being on other planets? + are some comets made of ice?
Comets are made of ice, mixed with a large amount of dust, frozen carbon dioxide and organic matter. Comets’ origin is the Oort cloud, which is thought to surround our solar system. I don’t think there is any PROOF of large amounts of oxygen on other planets, but there may be proof of small amounts (like 0.02%) on some planets. But yes, oxygen and ice are common in the universe. In case you didn’t know, there is ice on Mars, and life is thought to have been brought to Earth by a comet.
