SPACE OBSERVATORIES

A spacecraft launched to observe the Sun, stars, and remote galaxies is called a space observatory. The HUBBLE SPACE TELESCOPE was the first really important space observatory.

WHY ARE OBSERVATORIES LAUNCHED INTO SPACE?

Earth’s moving atmosphere bends and distorts the light from distant stars and galaxies. In space, observatories can see far more clearly. They can also pick up radiation (such as X-rays) that we cannot detect on Earth because it is absorbed by molecules in the atmosphere.

HUBBLE SPACE TELESCOPE

Launched from the Space Shuttle Discovery in 1990, the Hubble Space Telescope (HST) orbits about 370 miles (600 km) above Earth. It sends back some of the most detailed images of the Universe ever seen.

HOW DOES THE HST WORK?

The HST is a reflecting telescope—it uses mirrors to gather and focus light. The focused light is fed to electronic cameras and infrared detectors to create images. The main light sensors are CCDs (charge-coupled devices), like the ones used in digital cameras.

Copyright © 2007 Dorling Kindersley