Hubble Telescope

First visualized in 1946 and then launched in 1990, the Hubble telescope monitors the heavens from its position orbiting the Earth. Images from the Hubble telescope are much clearer than those taken by telescopes on the Earth as there is no atmosphere, which means light is coming only from distant space objects and not reflecting off the various atmospheric layers. Named after Edwin Hubble, the man who made the astonishing discovery that the universe is expanding with his observations of distant galaxies, the telescope now monitors distant galactic events.

Creating the telescope was a massive challenge. Not only would it be a high performance telescope capable of viewing distant galaxies clearly, it would have to cope with massive changes in temperature as it orbits the Earth traveling closer and then further from the Sun. Scientists came up with a multi layered insulating shroud which keeps the telescope at a more or less constant temperature.

A big job, the mirrors for the telescope were ground and then polished from early 1979 to May 1981, a total of two years! They were kept as light as possible using a low expansion glass to which was added a reflective coat of aluminum and a protective layer of magnesium fluoride.

Once the telescope was launched, the problems weren’t over and in 1993 just a few years after launch, a service mission had to be launched to fix a malfunctioning mirror that was causing a loss of picture quality. In 2007, after over a decade and a half of service, its main camera and several gyroscopes that keep the telescope stable stopped working. A service mission will fix these problems allowing the telescope to continue to take wonderful images until 2013 when it will be replaced by the new James Webb Space Telescope. The new telescope will be able to take even more detailed and spectacular pictures, but only in infrared.

The Hubble telescope has given us unprecedented images of comets, planets, stars and galaxies as well as establishing the existence of black holes which can only be seen through their effect on light and nearby objects.

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