LiveScience.com livescience Staff
livescience.com – Mon Aug 31, 2009
The search for the best observatory site in the world has lead to the discovery of what is thought to be the coldest, driest, calmest place on Earth - a place where no human is thought to have ever set foot on.
To search for the perfect site to take pictures of the heavens, a U.S.-Australian research team combined data from satellites, ground stations and climate models in a study to assess the many factors that affect astronomy - cloud cover, temperature, sky-brightness, water vapor, wind speeds and atmospheric turbulence.
The researchers pinpointed a site, known simply as Ridge A, that is 13,297 feet (4,053 meters) high up on the Antarctic Plateau on the continent at the bottom of the world.
The study revealed that Ridge A has an average winter temperature of minus 94 degrees Fahrenheit (minus 70 degrees Celsius) and an extremely low amount of water in the air.
The site is also extremely calm, which means that there is very little of the atmospheric turbulence that elsewhere makes stars appear to twinkle.
"It's so calm that there's almost no wind or weather there at all," said study leader Will Saunders, of the Anglo-Australian Observatory in Australia.
All these elements combine to make the perfect recipe for an astronomical observation post: "The astronomical images taken at Ridge A should be at least three times sharper than at the best sites currently used by astronomers," Saunders said. "Because the sky there is so much darker and drier, it means that a modestly-sized telescope there would be as powerful as the largest telescopes anywhere else on earth."
The site would even be superior to the best existing observatories on high mountain tops in Hawaii and Chile, Saunders said. Researchers assert that a telescope at the site could take images nearly as good as those from the space-based Hubble telescope (http://www.space.com/).
Located within the Australian Antarctic Territory, the site is 89 miles (144 km) from an international robotic observatory and the proposed new Chinese 'Kunlun' base at Dome A, a higher point on the Antarctic Plateau.
The finding was detailed on Aug. 31 in the Publications of the Astronomical Society.
...appear to twinkle
The Antarctic
No comments:
Post a Comment