What is 3D Asteroid Catalogue?

Spacecrafts provide the best information possible about a minor body but spacecraft missions are very difficult and expensive. Such missions often cost billions of dollars and take years to complete due to huge distances and complexity of orbital mechanics. Still, they provide us with the most detailed information about a space body, including radar and laser altimetry, surface samples and of course images in all kinds of spectra.

A number of objects (433 Eros, 25143 Itokawa, 4 Vesta, 67P/Churyumov-Gerasimenko and more) has been visited by space probes, resulting in a large amount of high-resolution photography and measurements, thus allowing scientists to create very precise models of these objects.

Radar Imaging is among the most precise methods, but also quite difficult and expensive way of obtaining asteroid shape data. It requres a set of large radio telescopes (with antenna diameter up to 70 meters) working together to obtain "images" of an asteroid from different angles. And the asteroid's position has to be the one that allows the radiotelescope to see it. However, the results are impressive - radar imaging allows to create a surface model of an asteroid with great precision and study its size, shape, rotation state, surface features and to improve the calculation of asteroid's orbit as well.

Most of the radar-based models on this website has been taken from JPL Asteroid RADAR Research page.

Lightcurve inversion is another method widely used to derive asteroid's shape, but rarely used for other types of bodies. It is based on a fact that asteroids shine by the reflected sunlight, and since the distance of an asteroid to the Sun and the Earth changes as the asteroid and the Earth orbit the Sun, the brightness of the asteroid changes as well. In addition, asteroids also exhibit brightness variations that are caused by their irregular shape and their rotation. This brightness variation is called a lightcurve. By measuring lightcurves, scientists can measure asteroid's rotation periods and derive a possible shape that would have produced such lightcurves.

Unfortunately, lightcurve inversion technique is not as precise as radar or spacecraft imaging and usually cannot predict all of the asteroid's surface features. In most cases, it can only create a convex shape, while the asteroids are mostly nonconvex. Still, it enables to reveal basic physical characteristics of individual asteroids.

Most of the lightcurve-inversion models on this website has been taken from DAMIT database.