Don’t Blink or You’ll Miss it

Have you ever seen a picture of a comet or asteroid in the sky against a background of stars? Here let me show you. Can you spot the asteroid? Okay I confess there is no asteroid in the image above, but if there was you’d believe me because an asteroid in this image would be indistinguishable from the stars.  They are all points of light, so how can you tell them apart? There’s something that separates asteroids, comets, planets, and all other solar system objects from background stars in an image. When you’re driving in a car and you look to the...

Why Pluto Isn’t a Planet, and Why it Was Before

The true story of why Pluto isn’t a planet goes back further than you would think.  It has a lot to do with our understanding of science at the time, and a lot more to do with surprising luck.  I made this video a couple of days ago for the Khan Academy Talent Search.  I hope you enjoy it. It will be interesting as we move into better telescope technologies that allow us to see further into the depths of the solar system and the universe.  What strange mysteries will we find?