LifePairs of habitable worlds could throw microbes at each other Some exoplanet systems have planets a fifth as close together as Earth is to Mars, a factor that could drive interplanetary fraternisation 51¶¯Âþ
EarthMost of Earth's mass extinctions caused by… mineral deficiencies Three of Earth's worst ever extinction events have no agreed cause – one unexplored possibility could be a fall in the abundance of minerals essential to life 51¶¯Âþ