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10 Years of Adaptive Optics at Europe’s VLT

November 25, 2011 Leave a comment

Credit: ESO, A. Prieto (MPIA, IAC)

Credit: ESO, A. Prieto (MPIA, IAC)

For non-astronomers, the twinkling of the stars can be quite romantic. For astronomers, it is the outward sign of a fundamental problem: As light passes through turbulent areas of the Earth’s atmosphere, it is deflected in uneven and ever-changing ways. What should be a sharp image of, say, a star in a telescope instead becomes a diffuse disk as the star’s image dances to and fro, or splits into several partial images. That is why, before adaptive optics, astronomers were forced to use space telescopes or else to wait for exceptionally good atmospheric conditions – which happen only a few times, if at all, in any given year – to obtain sharp images of celestial objects.

At least for images in the near-infrared, at slightly longer wavelengths that those of visible light, astronomers can also address the problem directly, using Adaptive Optics (AO): The ever-changing image is analyzed by a fast computer which, in real time, controls a deformable mirror. As the image dances and splits, the mirror twists warps and to compensate, restoring sharpness.

The NACO instrument was the first Adaptive Optics system at the VLT, the flagship facility for European ground-based astronomy. Installed on one of the VLT’s four 8,2 metre telescopes in 2001, it commenced scientific operations (“first light” in astronomical parlance) on November 25, 2001.

Full Story: http://www.mpia.de/Public/menu_q2e.php?Aktuelles/PR/2011/PR111125/PR_111125_en.html

Cassini Significant Events 11/16/11 – 11/22/11

November 25, 2011 Leave a comment

The most recent spacecraft telemetry was acquired on November 22 from the Deep Space Network tracking complex at Canberra, Australia. The Cassini spacecraft is in an excellent state of health and with the exception of the CAPS instrument being powered off, all subsystems are operating normally. Information on the present position and speed of the Cassini spacecraft may be found on the “Present Position” page at: http://saturn.jpl.nasa.gov/mission/presentposition/.

Full Story:  http://saturn.jpl.nasa.gov/news/significantevents/significantevents20111123/

Mars Science Laboratory Launch Milestones

November 25, 2011 Leave a comment

NASA’s Mars Science Laboratory is tucked inside its Atlas V rocket, ready for launch on Saturday, Nov. 26, 2011 from Cape Canaveral Air Force Station in Florida. The Nov. 26 launch window extends from 7:02 a.m. to 8:45 a.m. PST (10:02 a.m. to 11:45 a.m. EST). The launch period for the mission extends through Dec. 18.

The spacecraft, which will arrive at Mars in August 2012, is equipped with the most advanced rover ever to land on another planet. Named Curiosity, the rover will investigate whether the landing region has had environmental conditions favorable for supporting microbial life, and favorable for preserving clues about whether life existed.

On Nov. 26, NASA Television coverage of the launch will begin at 4:30 a.m. PST (7:30 a.m. EST). Live launch coverage will be carried on all NASA Television channels. For NASA Television downlink information, schedule information and streaming video, visit: http://www.nasa.gov/ntv . The launch coverage will also be streamed live on Ustream at http://www.ustream.tv/nasajpl .

Full Story: http://www.jpl.nasa.gov/news/news.cfm?release=2011-361