Detecting an Asteroid

Astronomers are continuously in search of new asteroids that could possibly hit Earth. Asteroids are discovered by detecting an object that has changed position in two or more pictures taken of a particular location in space. After the first night an asteroid is discovered, additional observations need to be done to measure the speed and direction of motion of the asteroid.

Let’s look at a typical asteroid. In this example, asteroid 2003_QZ30 was observed at three different times during the same night. Each time, the position of the asteroid was measured.