Did you know you can participate in a scientific investigation of a distant asteroid with just your smartphone?

Occasionally the orbit of an asteroid out in the main Asteroid Belt carries it directly between Earth and a distant star. Occultation lets you capture the times of disappearance and reappearance of the star as the asteroid passes in front of it - just tap your phone screen when the star winks out and tap again when it reappears. In this way you can join in the scientific measurement of the size and shape of the asteroid.

Occultation also makes it easy to report a ‘miss’, when the asteroid just misses covering the star from where you are standing and no disappearance is seen. ‘Miss’ reports are also extremely valuable for determining the size and orbit of asteroids.

The International Occultation Timing Association (IOTA) is a volunteer organization that provides free predictions of where and when asteroid occultations may occur. Your observation will be automatically transmitted to IOTA's servers to be combined with all other observations of the same event. The more observers that participate in timing an occultation, the more accurately the shape and size of the asteroid can be determined. More information including predictions of future occultations and locations from which they can be seen can be obtained at www.occultations.org .