[meteorite-list] Early Warning of Dangerous Asteroids and Comet (Lincoln Lab Telescope)

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon, 17 Nov 2008 12:24:45 -0800 (PST)
Message-ID: <200811172024.MAA09588_at_zagami.jpl.nasa.gov>

http://web.mit.edu/newsoffice/2008/panstarrs-1117.html

Early warning of dangerous asteroids and comets
Detectors developed at Lincoln Laboratory deployed in powerful telescope
David Chandler, MIT News Office
November 17, 2008

Silicon chips developed at MIT Lincoln Laboratory are at the heart of a
new survey telescope that will soon provide a more than fivefold
improvement in scientists' ability to detect asteroids and comets that
could someday pose a threat to the planet.

The prototype telescope installed on Haleakala mountain, Maui, will
begin operation this December. It will feature the world's largest and
most advanced digital camera, using the Lincoln Laboratory silicon
chips. This telescope is the first of four that will be housed together
in one dome. The system, called Pan-STARRS (for Panoramic Survey
Telescope and Rapid Response System), is being developed at the
University of Hawaii's Institute for Astronomy.

"This is a truly giant instrument," said University of Hawaii astronomer
John Tonry, who led the team developing the new 1.4-gigapixel camera.
"We get an image that is 38,000 by 38,000 pixels in size, or about 200
times larger than you get in a high-end consumer digital camera."

Pan-STARRS, whose cameras cover an area of sky six times the width of
the full moon and can detect stars 10 million times fainter than those
visible to the naked eye, is also unique in its ability to find moving
or variable objects.

Lincoln Laboratory's charge-coupled device (CCD) technology is a key
enabling technology for the telescope's camera. In the mid-1990s,
Lincoln Laboratory researchers Barry Burke and Dick Savoye of the
Advanced Imaging Technology Group, in collaboration with Tonry, who was
then working at MIT, developed the orthogonal-transfer charge-coupled
device (OTCCD), a CCD that can shift its pixels to cancel the effects of
random image motion. Many consumer digital cameras use a moving lens or
chip mount to provide camera-motion compensation and thus reduce blur,
but the OTCCD does this electronically at the pixel level and at much
higher speeds.

The challenge presented by the Pan-STARRS camera is its exceptionally
wide field of view. For wide fields of view, jitter in the stars begins
to vary across the image, and an OTCCD with its single shift pattern for
all the pixels begins to lose its effectiveness. The solution for
Pan-STARRS, proposed by Tonry and developed in collaboration with
Lincoln Laboratory, was to make an array of 60 small, separate OTCCDs on
a single silicon chip. This architecture enabled independent shifts
optimized for tracking the varied image motion across a wide scene.

"Not only was Lincoln the only place where the OTCCD had been
demonstrated, but the added features that Pan-STARRS needed made the
design much more complicated," said Burke, who has been working on the
Pan-STARRS project. "It is fair to say that Lincoln was, and is,
uniquely equipped in chip design, wafer processing, packaging, and
testing to deliver such technology."

The primary mission of Pan-STARRS is to detect Earth-approaching
asteroids and comets that could be dangerous to the planet. When the
system becomes fully operational, the entire sky visible from Hawaii
(about three-quarters of the total sky) will be photographed at least
once a week, and all images will be entered into powerful computers at
the Maui High Performance Computer Center. Scientists at the center will
analyze the images for changes that could reveal a previously unknown
asteroid. They will also combine data from several images to calculate
the orbits of asteroids, looking for indications that an asteroid may be
on a collision course with Earth.

Pan-STARRS will also be used to catalog 99 percent of stars in the
northern hemisphere that have ever been observed by visible light,
including stars from nearby galaxies. In addition, the Pan-STARRS survey
of the whole sky will present astronomers with the opportunity to
discover, and monitor, planets around other stars, as well as rare
explosive objects in other galaxies.

Detailed information about the Pan-STARRS design and its science
applications can be found at http://pan-starrs.ifa.hawaii.edu/public/.
The project was funded by the U.S. Air Force Research Laboratory.
Received on Mon 17 Nov 2008 03:24:45 PM PST