10 THINGS February 19

This Week: All About TRAPPIST-1

Forty light-years away, seven Earth-size planets closely orbit a faint star called TRAPPIST-1. We now know more about this system than any other beyond our own.

Image of the Week


A Girl Scout waits to look through a telescope at White House campout in 2015,

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Featured Video

How Sunlight Pushes Asteroids


Rotating asteroids have a tough time sticking to their orbits. Their surfaces heat up during the day and cool down at night, giving off radiation that can act as a sort of mini-thruster.
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