[meteorite-list] New Telescope to Revolutionize Asteroid Warning System

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed Dec 21 12:44:20 2005
Message-ID: <200512211742.jBLHgkd02953_at_zagami.jpl.nasa.gov>

http://space.com/businesstechnology/051221_pan-starrs.html

New Telescope to Revolutionize Asteroid Warning System
By Robert A. Myers
space.com
21 December 2005

HONOLULU -- The Solar System is about to look a lot more crowded.

A group of telescopes using the world's biggest digital cameras will
soon start scanning the sky from the Hawaiian Islands, tracking down
thousands of the smaller, dimmer and overlooked objects in the Sun's
neighborhood. The reason? Hunting for those dangerous space rocks that
still elude detection.

When fully operational, the Panoramic Survey Telescope and Rapid
Response System (Pan-STARRS) project will deeply scan most of the night
sky several times a month. About three-quarters of the sky are visible
from the Hawaiian Islands, and Pan-STARRS will use four linked
telescopes connected to its enormous cameras to take broad pictures of
unprecedented detail. Objects as dim as 24th magnitude - 250 times fainter
than objects detected by the current champ in asteroid spotting
LINEAR - will pop out of the background and be analyzed for their threat
potential.

In January of 2006 the first of the four will see first light, looking
forward to when the entire system is operational in 2009. Pan-STARRS
will bolster the Earth's early warning system for threats from asteroids
and comets - a congressionally directed program that currently consists of
LINEAR (Lincoln Near-Earth Asteroid Research), LONEOS (Lowell
Observatory Near Earth Object Search), NEAT (Near Earth Asteroid
Tracking) and Spacewatch.

Dr. Nick Kaiser of the University of Hawaii's Institute for Astronomy
(IfA) is chief scientist on the project, and has taken it in a slightly
different direction that first envisioned.

"(The National Academy of Sciences) had in mind a single ~6m (about 18
ft.) telescope but we had been playing around with the idea of doing
this with a cluster of smaller telescopes, for reasons of cost and speed
of construction, and thought that these had a competitive advantage,"
says Kaiser. Instead, Pan-STARRS will use a collection of four 1.8m
(about five ft.) telescopes, set to take wide images and linked via
computer to yield a final image as detailed as if a single 3.6m (about
12 ft.) telescope were used.

Big cameras, tiny targets

As the first telescope in the array, named PS1, nears completion, work
continues on the four revolutionary cameras that will make the work
possible. Digital cameras, which use no film and send their data
directly to a computer for analysis, have been the standard for
professional astronomy for years. But the ability to quickly scan large
swaths of the sky for the faint lights of possible threats is beyond any
current models. The new units have to be bigger, better, faster and cheaper.

And Kaiser says they will be.

"The goal that we set was to build cameras with 10 times as many pixels,
that could be read out 10 times as fast (to enable us to rapidly scan
the sky), and for one tenth the current cost per pixel! Amazingly, the
IfA detector group (along with MIT's Lincoln Laboratory) are rapidly
closing in on this goal," he said. "The cameras will each have 1.4
billion pixels and will be read out in a few seconds as the telescope
slews to a new target."

Photographed through the unusually wide-angled telescopes, each 30-60
second exposure will take up about 2 Gigabytes of data, and take about a
minute for the computers to process. At this rate, Pan-STARRS will be
collecting about 10 Terabytes of data each night.

"There has been rapid evolution in wide field (digital cameras) in the
last decade or so," Kaiser explained, "with major contributions from the
Hawaii detector group, and many people realized that the time was right
for a major leap forward."

Danger, falling rocks

When these "wide screen" high-definition images finally start rolling
in, turning the trickle of new potential dangers into a torrent, it
could easily overwhelm the established system for handling them.

"The current mode of operations for asteroid/NEO searches is for the
various observing projects (and amateurs) to send their detections to
the Minor Planet Center ... (which) acts as a clearing house and they
determine orbits for the objects and make these available to the general
community," said Kaiser. "A problem with this model for Pan-STARRS is
that our rate of detections will be much higher and would swamp the
current system."

Kaiser says they plan on handling most of the analysis of orbits
themselves. But it's all part of how hunting for these dangerous objects
have changed in recent years, as more sensitive instruments come online,
and public awareness (and occasional paranoia) grows.

"What happens is that every so often an object is detected that has a
small, but not vanishingly small, chance of hitting the earth some time
in the future," Kaiser explained. But one observation is never enough to
rule out danger, and it takes the work of observers across the globe to
nail down a new object's path -- a process that can hardly be done in
secret.

"While it may seem confusing to the public," Kaiser explained, "that
discoveries of potentially hazardous asteroids are announced and then
fairly rapidly declared to be non-hazardous, this is in fact inevitable."
Received on Wed 21 Dec 2005 12:42:46 PM PST