Happy birthday to the Hubble telescope

THE Hubble Space Telescope (哈勃太空望遠鏡), surely the most famous space telescope in the world, celebrated its 25th anniversary in late April. The good news is that there is a high probability it will keep working until 2020, and possibly into the 2030s!

The orbiting observatory is about 13 metres long and weighs 11,110 kilograms. It was named after the American (美國的) astronomer Erwin Hubble, who in the 1920s proved that the universe is expanding. A space telescope is not just a telescope that observes space. It is one that is located high up in space, out of Earth’s atmosphere, so that images will have minimal distortion.

Launched into orbit on 24 April 1990 by the space shuttle Discovery (發現號), Hubble has since travelled over 5.4 billion kilometres, circling Earth nearly 137,000 times! It has made more than 1.2 million observations of more than 38,000 celestial objects. The most faraway objects spotted by Hubble are early galaxies about 13 billion light years away from us.