Profile of the binary asteroid (90) Antiope from
an occultation on Jul 19, 2011

Welcome to the home page of the International Occultation Timing Association (IOTA).  IOTA is a volunteer science and research organization born in 1983.  We gather data from timings of astronomical occultations and provide a variety of educational resources to promote and encourage observations of astronomical occultations.

We provide predictions of occultations of stars by asteroids and the Moon, and of grazing occultations of stars by the mountains of the Moon’s north and south polar regions.  By observing and timing occultations, amateurs have contributed to the discovery of new double stars, improved knowledge of the shape and orbits of hundreds of asteroids and helped map the Lunar polar regions.

We provide information and recommendations on observing equipment and techniques, and we report and publish our data in scientific journals.  Amateur astronomers at all levels of experience are encouraged to become “citizen-scientists” and join in this exciting branch of astronomy.