Where did the two natural satellites of Mars, Phobos and Deimos, come from? For a long time, their shape suggested that they were captured asteroids. However, the shape and course of their orbits contradict this hypothesis. Two independent and complementary studies now provide an answer: these satellites formed from the debris of a gigantic collision between Mars and a protoplanet one-third its size.
An international team of scientists has found evidence of a major asteroid impact that occurred approximately 3.5 billion years ago. Tiny glass beads called spherules formed from vaporised material from the asteroid impact were found in a drill core from Australia in some of the oldest known sediments on Earth.
Unbeknown to two European amateur astronomers 1000 miles apart capturing video of Jupiter through their telescopes in the early hours of Thursday, 17 March, their digital footage would subsequently show confirmation of a totally unexpected phenomenon — the likely impact of a small comet or asteroid on the edge of the solar system’s largest planet.