If you’ve ever peered at a full moon through a telescope you’ve probably noticed a star or two near the edge. You’ll notice the Moon moving with respect to the star — evidence of the Moon’s rapid movement around the Earth, and even our own globes fast spin on its axis. If you monitor the orbiting globe for only a few minutes you might see that star drift behind it.

The moon often blocks, or occults, stars from our view. And human beings have been watching since Aristotle recorded the Moon covering Mars on April 4, 357 B.C. Sky & Telescope will help you know when these occultations are going to occur. And we’ll walk you through how your own observations may provide valuable scientific data, which may further map the luminous landscape hundreds of thousands of miles away.

Occultation Web Resources

Occultations of stars and planets by the Moon and asteroids are exciting to watch, and amateur occultation timings can have real scientific value. But first you need to know what occultations will be happening in your area.

An Occultation Primer

The Moon frequently passes in front of stars. In rare cases, planets and asteroids will also obscure starlight for a short time. Here are some basic definitions that will help you understand what occultations are about.

Saturn Hides Another Star

On Tuesday November 25th, Saturn and its ring system glide in front of an 8.3-magnitude star in Gemini, the second time Saturn has occulted a star in 10 days.

Saturn Transits the Crab

During the night of January 4–5, North American observers are well positioned to watch Saturn transit the face of M1, the Crab Nebula. But will the glare from the planet obscure the nebula?