Science

'Hello Earth! Can You Hear Me?'

That was the tweet sent by the European Space Agency's Philae space lander on Sunday morning. Last November, after touching down on Comet 67P, Philae went silent. On Saturday night, it communicated with scientists for the first time since. NPR's Arun Rath speaks with Mark McCaughrean of the European Space Agency about Philae's wakeup.