Why don't other planets have rainbows? It rains on other planets, some storms last decades. We have found trace evidence of water on Mars. Jupiter has an anticyclonic storm railing for the 179 years prior and possibly 300+ ongoing! It think Jupiter is overdue for a phatty air-ribbon. Are there no rainbows elsewhere because there aren't people around to enjoy them? Venus and Mercury are wicked jeally of our rainbows, son! Earth's ballin. For further discussion visit this less stale site.