Planetary scientists have discovered pieces of opal in a meteorite found in Antarctica, a result that demonstrates that meteorites delivered water ice to asteroids early in the history of the solar system. Opal, familiar on Earth as a precious stone used in jewellery, is made up of silica (the major component of sand) with up to 30 percent water in its structure.
Two years ago, on February 15th, the morning routine of the Chelyabinsk region in Russia was shattered by the arrival of a 20-metre-wide meteoroid that dramatically fragmented in the atmosphere. The ensuing shockwave shattered windows, damaged buildings and 1,491 people received injuries. What have we learned since 2013?