A powerful new automatic telescope has begun watching the sky for deadly asteroids or comets on a collision course with Earth. The giant eye – a 1.8 meter wide mirror fitted with a 1.4 BILLION pixel camera – is monitoring the heavens through the night from a mountaintop in Hawaii.
It is feeding a steady stream of images by fibre-optic cable down to a bank of more than 100 computers at sea level. Each snapshot contains an incredible 2 gigabytes of data.
There they are swiftly processed to pick out any points of light that are moving and so could be incoming cosmic missiles.
The telescope, called Pan-STARRS 1, is the first of four that will make up the Panoramic Survey Telescope and Rapid Response System. They are due to be completed by 2012.
As well as looking out for Armageddon, the telescopes will make astronomical discoveries for an international consortium including the UK universities of Durham, Edinburgh and Belfast.
When completed, the four will work together to target the same region of the sky at any time, covering a field about three degrees wide, or six times the apparent diameter of the Full Moon.
Operating in survey mode, the combined cameras will scan the sky bit by bit, allowing it all to be examined around once per week.
Though Pan-STARRS 1 has just officially gone into operation, it has already proved its potential during testing by discovering more than 30 supernovae.
Pan-STARRS’ principal investigator Professor Nick Kaiser, originally from Sheffield, Yorks, said it will take decades to detect all asteroids down to 100 meters wide that are in orbits threatening Earth.
But he said the telescopes will benefit several areas of astronomy. He said: “Most stars will be checked maybe six times in a year – enough to tell how they move and their distances.
“In the outer solar system we should discover ten times as many objects as are already known within a year or two.
“Cosmology takes longer. We’ll investigate dark energy. It forms 70 per cent of the energy density of the universe yet we don’t know what it is. We will also measure how the universe has expanded and how its structure is growing by studying weak gravitational lensing and viewing the echo of sound waves from the early universe.”
Last year, an asteroid up to a mile wide crashed into giant planet Jupiter leaving an impact scar the size of the Earth.
Earth has had a number of near misses in recent years. And the threat of an impact by a cosmic missile called Apophis in 2036 has still not been ruled out, though it is highly unlikely to happen.
The asteroid, which is 300 meters wide and weighs 25 million tons, will pass closer than geostatinary satellites in 2029 – an encounter that may make it hit us seven years later with the force of 65,000 atomic bombs.
• Discover space for yourself and do fun science with a telescope. Here is Skymania’s advice onhow to choose a telescope. We also have a guide to the different types of telescope available. Check out our monthly sky guide too!
