1,400 megapixel telescope powered-up to spot earthbound asteroids
June 23, 2010
If there’s a killer asteroid or comet hurtling towards Earth it’s probably best to know about it sooner rather than later. However, space is a big place and keeping our eyes out for these little blighters is no mean feat even with a mighty automated telescope to hand. Fortunately, astronomers in Hawaii have just announced they’ve successfully managed to boot up the Pan-STARRS (Panoramic Survey Telescope & Rapid Response System) telescope, also know as PS1.
Working from dusk-to-dawn every night Pan-STARRS is able to map one-sixth of the sky each month, allowing astronomers to track every moving object, calculate their orbits and identify any potential threats to Earth.
There are four Pan STARRS cameras in total, each capable of capturing around 1.4 billion pixels over a sensor measuring 40 centimeters square. The focal plane of each camera contains an almost complete 64x64 array of CCD devices, each containing approximately 600 x 600 pixels, for a total resolution of 1.4 gigapixels.
Scientists decided to opt for a greater number of small CCDs rather than less larger for a few practical reasons. First of all, smaller CCDs can be read out more quickly than larger, and of course, if you have a technical glitch on one larger CCD it can drastically effect image quality. Add to that the cost involved in replacing a large, expensive CCD as opposed to a few smaller.
The powerful 1,400 megapixel Pan-STARRS will give astronomers the chance to spot small, faint bodies in the outer solar system that were previously unavailable in sky surveys. It also has enough power to photograph an area of the sky as large as 36 full moons in a single exposure. To put this into perspective, a picture from the Hubble Space Telescope’s camera is only able to capture one-hundredth the size of a full moon at any one time.
If you were inclined to print out an image captured by the Pan-STARRS telescope as a 300-dpi photograph it would be large enough to cover half a basketball court. And, because PS1 captures an image every 30 seconds you would need to stock up on 1,000 DVDs every night to store the data.
This giant telescope sits at the top of the dormant volcano, Haleakala in Hawaii chosen for its clear skies and the well-developed technical and scientific expertise available on the island.
Shedding some light on the potential of the U.S Air Force-funded telescope, Smithsonian astronomer Matthew Holman explained: “PS1 will discover an unprecedented variety of Centaurs [minor planets between Jupiter and Neptune], trans-Neptunian objects, and comets. The system has the capability to detect planet-size bodies on the outer fringes of our solar system.”
Even so soon in its operation scientists have revealed PS1 has been able track down several hundred transient objects every month. These findings would have previously taken a couple of years.
(Photographs of telescope by Brett Simison. Space images captured by Pan-STARRs via the Institute for Astronomy, University of Hawaii.)