!(https://images.twnmm.com//c55i45ef3o2a/thZgLtn2qnQphDRru9Ai2/569e470e9056bd2d6ddf7ab85a8baac4/Earths_Rings_from_Griffith_Observatory_Kevin_Gill_Wikimedia.jpg)*Saturn-like rings shine in the sky over Griffith Observatory in this simulated image. (Kevin Gill (CC BY-SA 2.0))*New research proposes that Earth once had...