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25 Years of Hubble Space Telescope

HUBBLE SPACE TELESCOPE 25TH ANNIVERSARY

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April 2015 marks the 25th birthday of the most famous telescope in the world. Things didn’t get off to a great start when it was discovered that the mirrors were ground to the wrong shape. Subsequent service missions restored Hubble’s eyesight and the telescope continues to provide us with valuable data and stunning imagery. Here are some of the best from the past 25 years.

Click here to see the images online

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25 Years of Hubble Space Telescope

It’s the most famous tel-escope in the world, and April 2015 marks its 25th

anniversary. Though it was launched with a flawed opti-cal system, the Hubble Space Telescope has become the most successful telescope ever built. Because it operates in space, the HST’s images aren’t blurred by atmospheric turbulence, and it can observe in wavelengths that don’t reach ground-based tel-escopes. It is also the most ex-pensive telescope ever built: $5 billions from NASA, plus several hundred million euros from the European Space Agency. But to astronomers who have gained new insights into the workings of the uni-verse, and the general public who have looked in wonder at Hubble’s amazing images, it is money well spent. The Hubble Space Telescope has already exceeded its design life by five years: astronomers expect it to last past 2020.

In April 1990, Shuttle mission STS-31 placed the bus-sized telescope into a perfect orbit 560 km above the Earth. Astronomers were jubilant –

until the first pictures taken by the telescope revealed a serious problem. The pictures were blurred. Investigations revealed that the 2.4 meter mirror – touted at the time as ‘the world’s most perfect mirror’ – had been ground to the wrong shape. The world’s most expensive telescope became a laughing stock.

Three years later, NASA launched a repair mission that was a major venture in itself, involving five days of space-walks to fit corrective optics popularly known as ‘Hubble’s spectacles’. The mission was a resounding success: the first pictures sent back to Earth were breathtaking. Hubble now had 20:20 vision.

Hubble has revolutionised our understanding of the universe. Here’s some of the telescope’s facts and achieve-ments:

The HST transmits about 120 gigabytes of science data every week. This is equal to about a kilometer of books on a shelf. Its accuracy is phenomenal: it can lock onto

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25 Years of Hubble Space Telescope

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25 Years of Hubble Space Telescope

SCIENCE PHOTO LIBRARY FEATURES

25 Years of Hubble Space Telescope

a target equivalent to the width of a human hair at a distance of well over a kilometer.

Hubble’s biggest ever image is a mosaic of 13,000 separate images of the neighbouring Andromeda galaxy. It took 39 months to assemble, and is so detailed that even though the Andromeda galaxy is two million light years away, most of its 100 million stars are clearly visible.

Because it looks so far into space, Hubble is essentially a time machine. Over a period of four months, Hubble focused on a small patch of sky in the Southern Hemisphere. The result of this longest of long exposures was the Hubble Ultra Deep Field, the deepest image of the universe ever taken. The HUDF contains thousands of galaxies, some of which are 13 bil-lion years old – seen as they existed just a few hundred million years after the Big Bang.

In 2008, Hubble took pictures of the extrasolar planet Fomalhaut b, the first direct image in visible light of a planet orbiting another star.

Hubble’s most popular image is the so-called ‘Pillars of Creation’, a star-forming region of the Eagle Nebula. This has been reproduced on book

and CD covers, T-shirts and posters - becoming one of the most popular astronomical images of all time.

In 2011, Hubble made its millionth observation – a spectroscopic analysis of the exoplanet HAT-P-7b.Hubble has narrowed down the age of the universe to about 13.7 billion years.

HST observations of star-forming regions have shown that discs of dust and gas that may eventually become planets surround many young stars. So alien worlds may well be common throughout the universe.

Hubble discovered that supermassive black holes are probably at the heart of most galaxies.

Hubble treated the world to one of the most spectacular Solar System events in a century – the collision of Comet Shoemaker-Levy with Jupiter in 1994. It showed massive fireballs and an Earth-sized impact feature as the massive planet destroyed the comet in a dramatic example of a multi-megaton cosmic impact.

ENDS 650 WDS © SCIENCE PHOTO LIBRARY 2015

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25 Years of Hubble Space Telescope

FULL PICTURE LIST: Click here to see the images online

SCIENCE PHOTO LIBRARY FEATURES

25 Years of Hubble Space Telescope

SCIENCE PHOTO LIBRARY FEATURES

25 Years of Hubble Space Telescope