The infrared spectrum is situated beyond the red end of the visible spectrum, depending on the certain heat waves. This is made possible only because of the characteristics of infrared.
Infrared observations show the cool state of matter.
Any type of body in space, wheather it be a planet or an asteroid have tempertures that span from 3K to 1500K. Most of this energy given off by the object is emitted in the infrared. The cosmic redshift that is a result from the expansion of the Universe will and still is shifting energy to longer wavelengths. Since the expansion of the Universe, most of the radiation emitted from such objects as stars or planets now lie in the infrared band. The Space Infrared Telescope Facility is designed to study the Universe at infrared wavelenghts. Scientists believe that the smaller particles in the disks should render the existitance of a larger body.