Infra-Red was the 'last' type of electromagnetic radiation to be employed in astronomy. It has two main problems
Infra-red detectors are not as sensitive as detectors for other frequencies
Detectors need to be coooled to extremely low temperatures (preferably a few degrees above zero), in order to cut-out the infra-red emissions from the detecting equipment itself.
Land-based Infra-Red telescopes are placed at high locations to avoid most of the Water Vapor and Carbon Dioxide which absorb Infra-Red strongly (they are well-known greenhouse gases).
All of the ultraviolet and much of the visible light from very distant sources is shifted into the infrared part of the spectrum by the time it reaches our telescopes. Infrared astronomy will provide a great deal of information on how and when the universe was formed and on what the early universe was like.
In space, there are many regions which are hidden from optical telescopes because they are embedded in dense regions of gas and dust. However, infrared radiation can pass through dusty regions of space without being scattered. This means that we can study objects hidden by gas and dust in the infrared, which we cannot see in visible light, such as the center of our galaxy and regions of newly forming stars.
Detection of possible planets around other stars.
UKIRT - UK Infra-Red Telescope
The world's largest telescope dedicated solely to infrared astronomy, UKIRT is situated in Hawaii near the summit of Mauna Kea at an altitude of 4194m. It is owned by the Particle Physics and Astronomy Research Council and operated, along with the James Clerk Maxwell Telescope (JCMT), by the staff of the Joint Astronomy Centre, which is located in Hilo. Dust
IRAS - InfraRed Astronomy Satellite
Dutch-led in which Britain and USA were also involved. Launched in January 1983 and operated for about 10 months before the liquid helium boiled away.