Look up! Today the "Green Comet" makes its closest approach to Earth for the 1st time in 50,000 years! After your viewing party, why not curl up with A History of Near-Earth Objects Research to learn about how we've come to understand comets and asteroids! https://go.nasa.gov/3XNt3bW #NASAhistory
Often seen as the solar system's rubble, asteroids and comets were largely ignored in the 20th century until recently. Increasingly, they have been seen by scientists as objects worthy of study, by the general public and the U.S.
