Radar astronomy

[2] Radar images provide information about the shapes and surface properties of solid bodies, which cannot be obtained by other ground-based techniques.

The combination of optical and radar observations normally allows the prediction of orbits at least decades, and sometimes centuries, into the future.

This was a target of great scientific value, since it could provide an unambiguous way to measure the size of the astronomical unit, which was needed for the nascent field of interplanetary spacecraft.

In addition such technical prowess had great public relations value, and was an excellent demonstration to funding agencies.

This led to early claims (from Lincoln Laboratory, Jodrell Bank, and Vladimir A. Kotelnikov of the USSR) which are now known to be incorrect.

[12] The following is a list of planetary bodies that have been observed by this means: Radar provides the ability to study the shape, size and spin state of asteroids and comets from the ground.

With sufficient data, the size, shape, spin and radar albedo of the target asteroids can be extracted.

[5] Being smaller, the Goldstone Solar System Radar is less sensitive and unable to provide the same predictive capacity.