Via Phil Plait comes the news that a fourth moon of Pluto has been discovered in new Hubble Space Telescope images.
The new object is tiny - just 8 to 21 miles across. Which isn't tiny compared to, say, Manhattan, but it is incredible when you realize that Pluto is currently three billion miles away. Which means that spotting the moon - provisionally designated S/2011 P1 - equivalent to having a marble orbiting a beach ball on top of the Empire State Building. And then spotting that marble from Chicago.
We've known about its largest moon, Charon, since 1978, but the two other moons, Nix and Hydra, were just discovered in 2005. Makes me wonder what we'll find next.
I can't wait till New Horizons shows up in 2015. We will learn a lot about Pluto and its moons very quickly.
The Boston Projection
1 day ago