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Looking Up: Vanishing Point

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1min 30sec
Vesta is an asteroid. It has a set of three craters known as the "snowman."
Vesta is an asteroid. It has a set of three craters known as the "snowman."
This image, taken by NASA's Near Earth Asteroid Rendezvous mission in 2000, shows a close-up view of Eros, an asteroid with an orbit that takes it somewhat close to Earth.
This image, taken by NASA's Near Earth Asteroid Rendezvous mission in 2000, shows a close-up view of Eros, an asteroid with an orbit that takes it somewhat close to Earth.

Sometimes when a thing becomes hidden, something else is revealed. Hal reveals an upcoming occultation in this week's episode of Looking Up. 

One of the great things about astronomy is that there are so many different things you can look at. Some astronomers are fascinated with planets, while others study entire galaxies. And there are some dedicated amateur astronomers that are all about asteroids – those hunks of material left over from the formation of our solar system.

Every now and then, an asteroid drifts across, and blocks or “occults” the light from a star. These occultations can provide lots of information about the asteroid. Some really dedicated amateur astronomers will set up a line of 20 or more telescopes with cameras in a line across the predicted eclipse zone of the occultation. That way, by combining the information gleaned from each telescope, they can get a fairly good idea of the size and shape of the asteroid.

And such an occultation is going to happen across much of the United States on the 16th. If you live in a band from northern California to Maine, you can point a telescope at the star HD 33864 in Taurus and see an asteroid named Sappho pass right in front. The star will wink out momentarily, and you can marvel at the wonders of the night sky, to say nothing of the ability of astronomers to predict amazing events with such accuracy. You can learn more and maybe even help out by visiting occultations.org, where the International Occultation Timing Association has all the best information on this and other upcoming occultations.

If you’d like to take a closer look an asteroid, or any of the other wonderful and amazing things in the sky, please visit csastro.org for a link to information on our monthly meetings and our free public star parties!