EarthShooting stars show Earth had oxygen eons before we thought Tiny meteorites discovered in Australia show that Earth's air had some oxygen in it at a time when no one thought it did – 2.7 billion years ago 51¶¯Âþ
EarthPlanets with too much carbon dioxide could lose oceans to space Adding vast amounts of CO2 to the atmosphere could heat a planet to the point where it leaks so much water that its oceans eventually disappear 51¶¯Âþ