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The Isaac Newton Group of Telescopes is an establishment of the Particle Physics and Astronomy Research Council (PPARC) of the United Kingdom, the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO) of the Netherlands and the Instituto de Astrofísica de Canarias (IAC) in Spain |
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Press Release ING
3/2002
Date: Wednesday 4 September 2002 Embargo: For immediate release Other available formats: PDF | TXT Mirror in UK: http://www.ast.cam.ac.uk/ING/PR/press/ing32002.html A SHARPER LOOK AT NEAR EARTH ASTEROID 2002 NY40
The Near Earth Asteroid 2002 NY40 was observed with the William
Herschel Telescope on La Palma, Canary Islands, on the night of August
17 to 18, 2002. The asteroid was imaged just before its closest approach to Earth,
using the Adaptive Optics system NAOMI. These are the first images of a Near
Earth Asteroid obtained with an Adaptive Optics system.
During these observations the asteroid was 750,000 kilometres away, twice
the distance to the Moon, and moving very rapidly across the sky (crossing a
distance similar to the diameter of the Moon in 6 minutes or at 65,000
kilometres per hour). Despite the technical difficulties introduced by this,
very high quality images were obtained in the near-infrared with a
resolution of 0.11 arcseconds. This resolution is close to the theoretical
limit of the telescope, and sets an upper limit to the size of the asteroid:
only 400 metres across at the time of the observations.
Measuring the size of asteroids helps astronomers understand their nature
and formation history as well as the potential threat they pose.
Near Earth Asteroids are a small population of asteroids that periodically
approach or intersect the orbit of our planet, and have the possibility of
colliding with the Earth as probably happened 65 million years ago, ending
the dinosaur era. However, the probability that such an impact could happen
is very low and in particular Near Earth Asteroid 2002 NY40 represents no
danger to human live on Earth.
Close encounters of large Near Earth Asteroids such as 2002 NY40 on August
18 happen approximately every 50 years. The last known case was NEA 2001
CU11 which passed just outside the Moon's orbit on August 31, 1925. Nobody
saw that approach because that asteroid was not discovered until 77 years
later. 2002 NY40 was discovered on July 14, 2002 by the LINEAR telescope in
New Mexico (USA), providing a unique opportunity to obtain observations of
the asteroid from the Earth during its flyby.
Several observers have reported variations in the brightness of 2002 NY40,
suggesting that it is highly elongated and tumbling. Further monitoring of
these variations will tell us whether the asteroid was viewed end-on or
side-on, and thus allowing the determination of the size and the shape more
precisely.
NAOMI is the WHT's Adaptive Optics system, built by a team from the
University of Durham and the Astronomy Technology Centre, UK. It
incorporates a system of fast-moving mirror elements which correct in
real-time for the defocusing of stars caused by the Earth's turbulent
atmosphere. In good conditions, NAOMI delivers images as sharp as those from
Hubble Space Telescope.
The Isaac Newton Group of Telescopes (ING) is an establishment of the
Particle Physics and Astronomy Research Council (PPARC) of the United
Kingdom, the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)
of the Netherlands and the Instituto de Astrofísica de Canarias (IAC)
in Spain. The ING operates the 4.2 metre William Herschel Telescope, the 2.5
metre Isaac Newton Telescope, and the 1.0 metre Jacobus Kapteyn Telescope.
The telescopes are located in the Spanish Roque de Los Muchachos Observatory
on La Palma which is operated by the Instituto de Astrofísica de Canarias (IAC). The ING NAOMI team consists of Dr. Chris Benn, Dr. Sebastian Els, Dr. Tom Gregory, Dr. Roy Østensen and Dr. Francisco Prada.
PICTURES AND MOVIES
FOR FURTHER INFORMATION PLEASE CONTACT:
Dr. Javier Licandro
Dr. Francisco Prada Dr. Sebastian Els
Mr. Javier Méndez
FOR FURTHER INFORMATION ON THE WEB:
More information on NAOMI: NAOMI home page.
More information on the Isaac Newton Group of Telescopes (ING): Public Information on ING |