05 Sep 2002
Observers take the first image of a near-Earth asteroid with an adaptive optics system.
Astronomers at the William Herschel Telescope (WHT) in the Canary Islands have released what they claim is 'the first image of a near-Earth asteroid obtained with an adaptive optics system'. The image was taken with the NAOMI camera, which is installed on the 4.2 meter telescope.
An adaptive optics system uses fast-moving mirrors to correct for atmospheric distortion in real-time. This allows ground-based astronomers to acquire images with resolution equal or exceeding that of space-based telescopes such as Hubble.
The image was taken in the infrared at a wavelength of 1.63 microns, the so-called H-band, and has a resolution 0.11 arcseconds. The team says this is close to the theoretical limit of the telescope.
During the observations made between August 17 to 18 this year, the near-Earth asteroid, named 2002 NY40, came within 750 000 kilometers of Earth - just twice the distance to the Moon.
The WHT is part of the Isaac Newton group (ING) of telescopes run by a collaboration of researchers in the United Kingdom, the Netherlands and Spain.
Jacqueline Hewett is news reporter on Optics.org and Opto & Laser Europe magazine.