We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Astronomy

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What is an Astronomical Occultation?

By S. Mithra
Updated: May 21, 2024

Astronomical occultation occurs when one celestial body eclipses, or blocks the light from, another celestial body from the Earth's perspective. Moons, planets, stars, small satellites, and asteroids can all interact to form an astronomical occultation with respect to a position on the Earth's surface. Many databases and organizations keep track of the orbits of our moon and various asteroids to predict visible occultations in the coming months. Amateur astronomers can observe these events to determine information such as the accuracy of that body's orbit or the topography of the moon.

Occult means "to hide." This is what occurs when the moon obscures a bright star for a brief period of time, for instance. That astronomical occultation would be visible to some locations of the Earth. The International Occultation Timing Association keeps records and publishes schedules of various kinds of astronomical occultation for the whole world. They track the Earth's position and orientation in the solar system with respect to the moon, orbiting asteroids, and distant stars. In 1977, astronomical occultation was the first method we used to see the rings of Uranus.

In popular astronomy, astronomical occultation provides events that hobbyists can analyze. They can actually produce new information without huge telescopes or sophisticated computers. All a backyard astronomer needs is a global positioning system, a 4-6" (10-15 cm) telescope, and a video-recording device. They can use these simple instruments to find smaller satellites orbiting an asteroid, find companions in binary star systems, determine the diameter and shape of larger asteroids, and improve scientists' records on positions of stars.

Amateur astronomers can even map the topography, the mountain ranges and deep valleys, near the polar regions of the moon. That's made possible by grazing occultation, where a star passes just along the edge of the moon, rather than direct occultation, where the star completely disappears behind the moon's body. During a grazing astronomical occultation, a star will be hidden by tall lunar mountains, then visible in a hollow valley, then obscured again by higher ground. Using mathematical calculations, you can determine the elevation of those mountains and the depth of the valleys with results impossible to conclude with even the most powerful telescopes.

All The Science is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
Share
All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.

All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.