A technique that is proving very useful for determining the shapes of a large number of asteroids is:
A)radar signals reflected from the asteroid's surface.
B)direct photography from spacecraft.
C)optical and infrared Doppler shift measurements as the asteroid rotates.
D)CCD photography using large, Earth-based telescopes.

Question

Quizplus · Accepted Answer

Radar signals reflected from the asteroid's surface can provide detailed information about its shape and surface features. This technique has been used extensively in recent years to study asteroids. Direct photography from spacecraft can also provide shape information, but it is only feasible for a few specific asteroids that have been visited by spacecraft. Optical and infrared Doppler shift measurements can provide information about rotation rate, but may not reveal shape details. CCD photography using large telescopes can also provide shape information, but is limited by the size of the telescope and atmospheric conditions.

A Technique That Is Proving Very Useful for Determining the Shapes