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Asteroid tracking is done in two different ways, by telescope and with radar. The Near Earth Asteroid Tracking, NEAT for short, program that NASA runs uses two telescopes and many other programs use delay-Doppler radar to get images and surface features of asteroids. The information gained by these programs may be used for different purposes, but they have both contributed greatly to the knowledge that we have about asteroids in general.
The NEAT program is interested in asteroid tracking that involves near Earth incidents only. Eleanor Helin was the first principal investigator for the program. There are two ground based electro-optical deep space surveillance (GEODSS) telescopes in service for the program. NEAT is a cooperative program between the Air Force and NASA. This is the program that produced the images leading to the discovery of 50000 Quaoar in 2002, and 90377 Sedna in 2003, and the dwarf planet Eris. In addition to discovering thousands of asteroids NEAT is also credited with the co-discovery of periodic comet 54/de Vico-Swift-Neat and of the high proper motion Teegarden’s star. The C2001 Q/4 (NEAT) comet was discovered on August 24, 2001 by NEAT.
Delay-Doppler radar is an extremely powerful tool in the search for information and in asteroid tracking. According to NASA,”Measurements of the distribution of echo power in time delay (range) and Doppler frequency (radial velocity) constitute two-dimensional images that can provide spatial resolution finer than 10 meters if the echoes are strong enough. With adequate orientational coverage, such images can be used to construct geologically detailed three-dimensional models, to define the rotation state precisely, and to constrain the object’s internal density distribution. Moreover, radar wavelengths are sensitive to near-surface bulk density and structural scales larger than a few centimeters.”
Asteroid tracking is an important aspect of today’s NASA mission. Impact events happen on a regular basis, but they are usually small enough objects that nothing of them survives the atmosphere. There are large enough objects to cause significant damage and loss of life if the impacted the Earth. That is why NEAT and delay-doppler asteroid tracking are necessary.
There is an interesting Astronomy Cast program about asteroids hitting the Earth.