Artificial light makes the modern world possible. But not all kinds of light are good for us. Electric light has fundamentally altered our lives, our bodies and the very nature of our sleep.
Philae made a thud, bounced, and hasn't been seen since by the Rosetta mother ship.
After 10 years of travel and three months orbiting the comet 67p/Churyumov-Gerasimenko, the European Space Agency's (ESA) Rosetta spacecraft is poised to deliver its landing probe, Philae, to the comet's surface -- a first in history.
On Monday, far beyond the orbit of Mars, an alarm clock went off and a robot began the slow process of waking up after a long, cold sleep. The European Space Agency's Rosetta spacecraft is now approaching the comet 67P/Churyumov–Gerasimenko, which it will catch up with this May.