These wavelengths of electromagnetic radiation are obscured from the ground by the Earth's atmosphere. Observers from around the world took advantage of this workhorse observatory, gathering data from a wide variety of astronomical sources. Objects observed by IUE include virtually every type of object in the universe, from planets and stars to galaxies. One of IUE's strengths was the ability to rapidly respond to targets of opportunity such as comets, novae, and supernovae. IUE obtained the only ultraviolet data of the outburst of Supernova 1987a in the Large Magellanic Cloud.
Astronomers study multiple wavelengths in order to learn more about the objects of the universe.
Simultaneous data acquisition is essential in order to gain the most knowledge of certain transient events. Thus, very often IUE was used in conjunction with other telescopes from around the world.