Occultations

Through occultations, we can measure the sizes, shapes, and positions of asteroids with greater accuracy than provided by space-based telescopes. Occultations can also be used to detect moons and rings around asteroids and planets.

Chasing Polymele’s Shadow

Join us as we travel with citizen scientists playing a crucial role for NASA’s LUCY mission.


On February 3, 2023, over 100 telescopes across two continents were deployed to observe the Trojan asteroid Polymele and its satellite during an occultation. In this episode, we'll learn about occultations which occur when an object, like an asteroid, passes in front of a star, momentarily blocking its light and sending a shadow towards Earth telescopes.
Occultation measurements provide valuable data about size, shape, and orbit, helping NASA plan for future flyby's of Jupiter’s trojan asteroids.

Chasing Polymele's Shadow

Persiguiendo la sombra de Polymele

Resources & Activities

  • Lucy Mission Activity Book: Explore the Lucy mission to the Trojan asteroids with this activity book. Available in both English and Spanish. Great for solo learners
  • Meet Lucy Coloring Page: Color your very own Lucy spacecraft. Great for solo learners
  • Follow along with Lucy: Follow Lucy’s journey to the Trojan asteroids with NASA’s Eyes on the Solar System.
  • NASA’s Eyes on Asteroids: Fully interactive, NASA’s Eyes on Asteroids uses data to visualize asteroid and comet orbits around the Sun.