The red dot in this picture is the first near-Earth asteroid discovered by NEOWISE. Near-Earth objects are those asteroids and comets with orbits that come relatively close to Earth's path around the sun. Asteroids stand out in NEOWISE images because they are cooler than stars and give off lower-energy (longer-wavelength) infrared light. In this view, shorter wavelengths of infrared light are colored blue, and longer wavelengths, red.
› Larger image
› Read more