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The International Ultraviolet Explorer

(1978 - 1996)

When the International Ultraviolet Explorer (IUE) went into orbit around the Earth in January 1978, Jimmy Carter was US president, Leonid Brezhnev presided in Moscow, and Abba ruled the pop charts. The IUE mission is a partnership of NASA, ESA and the British government..

IUE was meant to last for three years but after 18 years in space it still refused to die and the partners decided to switch it off. Until 1996, astronomers were still queuing up to use the instrument that worked non-stop since its launch 18 years earlier. Operations finally ceased on 27 September 1996, making it one of the biggest success stories in space science so far.

IUE made, on average, one one-hour observation every 90 minutes. It intercepted ultraviolet light that can't reach telescopes on the ground, and saw everything from supernovae far away to approaching comets.

In the history of space astronomy IUE is the most long-lived and by far the most productive satellite this far. Some of the most well-known and important observations included Halley's Comet (1986), a supernova event in a nearby galaxy (1987) and Comet Shoemaker-Levy crashing into Jupiter (1994). Astronomers continue to work with the enormous amount of data now stored in the IUE final archive.

A supernova event in 1987

The event of the century for astronomers was the explosion of a massive star. Supernovae are crucial in cosmic history, and the source of the Earth's gold and uranium, none had before been seen at close range with modern instruments. Stargazers spotted Supernova 1987A in February 1987, in the Large Magellanic Cloud in the southern sky. When the news broke, the very first space telescope to turn towards Supernova 1987A was IUE.

As the supernova faded rapidly in the ultraviolet, IUE's experts could say, years before other observers, exactly which star blew up. The satellite registered ultraviolet signatures of newly-made chemical elements released by the explosion.

IUE links

European Space Agency's (ESA) IUE page

Another ESA page about IUE

About IUEs mission (also ESA)

28th July 2000
Emma Button
Sarah Amandusson