Why is infrared radiation important to astronomy?
Most of the light in the Universe is in infrared and longer wavelengths. There are three basic reasons for this: • It’s cold out there. Many of the things scientists want to observe in space are far too cold to radiate at optical or shorter wavelengths. However, even at temperatures far below the coldest spots on Earth, they do radiate at far-infrared and submillimeter wavelengths. To understand how stars form and evolve, we need to understand their raw materials – the cold atoms and molecules that populate interstellar space. They radiate most strongly in Herschel’s range. Analyzing their spectra will enable scientists to determine the temperature, density, luminosity, composition, magnetic fields, and dynamics of the chemicals and their environments. In our own solar system, cold objects such as comets, asteroids, and the planets themselves reveal most of their characteristics by infrared light. Brown dwarfs, protostars, dusty disks around young stars, and planets in other star syste