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The Minor Planet Center (MPC) is an international organization responsible for collecting observations of asteroids, comets, and other small bodies in the Solar System. Under the authority of the International Astronomical Union (IAU), the MPC maintains and publishes information on the most up-to-date observations of these Solar System objects and their orbits. The MPC is hosted by the Center for Astrophysics | Harvard & Smithsonian, and sponsored by a grant from NASA’s Near-Earth Object Observations program.

Visit the MPC website

This artist’s impression shows the first interstellar asteroid: `Oumuamua. This unique object was discovered on 19 October 2017 by the Pan-STARRS 1 telescope in Hawai`i. Subsequent observations from ESO’s Very Large Telescope in Chile and other observatories around the world show that it was travelling through space for millions of years before its chance encounter with our star system. `Oumuamua seems to be a dark red highly-elongated metallic or rocky object, about 400 metres long, and is unlike anything normally found in the Solar System.

ESO/M. Kornmesser

Artist's impression of the main asteroid belt lying between the orbits of Mars and Jupiter. Based on infrared surveys, astronomers estimate between 700,000 and 1.7 million asteroids larger than 1 kilometer reside in the main belt.

Peter Veres/Cosmographia


Small Worlds

Along with the major planets — Earth, Jupiter, and so forth — the Solar System is home to many small bodies including asteroids, comets, Kuiper Belt objects like Pluto, and their satellites. While the major planets follow predictable orbits around the Sun, these small worlds are sometimes difficult to observe because of their size, low brightness, and distance from Earth. Determining the precise geometry of their orbits is often challenging, and some of the orbits change over time due to gravitational nudges from the planets or the Sun heating their surfaces.

The Minor Planet Center collects observational data from professional and amateur astronomers, recording the discoverer and name of each object. This data is particularly important for tracking near-Earth objects (NEOs), which are asteroids that pass relatively close to Earth. Some of these NEOs are potentially dangerous, but their proximity to us also makes them important observational targets. To date, the MPC has data on over 700,000 minor planets, including over 18,000 NEOs. All MPC data is available to the general public through the website.


Learn More about the Minor Planet Center