The lunar landscapes of Chile's Atacama Desert, which stretches for about 650 miles along the Pacific Ocean to the Peruvian Border, is generally considered the driest place on earth, wedged between the rain shadows of the Andes to the east and the coast ranges to the west, while the cold Humboldt Current off the coast suppresses evaporation from the ocean. There are places in the Atacama where there has been no recorded or observed rainfall in the 400+ years since the Spaniards first arrived.
The Atacama Desert's dry climate and 5,600-meter (about 3.5 miles) altitude make it a unique and ideal mecca for both ground-based reflector and far-infrared astronomy. The southern hemisphere skies were opened with the construction of the Carnegie 100-inch DuPont telescope at Las Campanas in 1977.
Thirty years later, Cornell and Caltech have announced the "Atacama Telescope Project To Revolutionize Astronomy," a proposed 25-meter aperture telescope that will be the largest, most precise and highest astronomical facility in the world.
The $100 million Cornell Caltech telescope, to be built in the Cerro
Chajnantor in the Atacama Desert region in Chile, will take advantage
of the rapid development in bolometer array technology (instruments
that measures radiant energy) to answer some of the most fundamental
questions of cosmology. Radiation at submillimeter wavelengths (longer
than visible light but
shorter than radio waves) is normally difficult to detect from the
ground because it is easily absorbed by water in the Earth's
atmosphere. Situating the telescope in the dry Atacama Desert
eliminates this problem.
Planners hope to begin construction this year and to see first light
in 2013 under the guidance of Riccardo Giovanelli, Cornell professor of
"CCAT is designed to optimize our ability to study the genesis of structures in the universe," said Giovanelli. "It will allow us to explore the process of formation of galaxies, which saw its heyday about a billion years after the big bang, some 13 billion years ago; to peek into the interior of the dusty molecular clouds within which stars and planets form; and to survey the pristine chunks of material left intact for billions of years on the outskirts of our solar system."
The telescope will also be a powerful survey tool, working 30 times faster than current facilities and with much greater sensitivity. Large-scale surveys of extremely distant galaxies could give scientists a better understanding of how galaxies were distributed as they formed and how their clustering properties evolved.
Nearby, on the Atacama's 5000 meter-high plateau of Chajnantor the European Southern Observatory's ALMA (Atacama Large Millimeter/submillimeter Array) Observatory project is a giant, international observatory currently in construction on the high-altitude Chajnantor site, and composed initially of 66 high-precision telescopes, operating at wavelengths of 0.3 to 9.6 mm.
The ALMA antennas will be electronically combined and provide astronomical observations which are equivalent to a single large telescope of tremendous size and resolution, able to probe the Universe at millimeter and submillimeter wavelengths with unprecedented sensitivity and resolution, with an accuracy up to ten times better than the Hubble Space Telescope.
ALMA will be the forefront instrument for studying the cool universe
- the relic radiation of the Big Bang, and the molecular gas and dust
that constitute the very building blocks of stars, planetary systems,
galaxies, and life itself.
Because ALMA will observe in the millimeter and submillimeter wavelengths the atmosphere above the telescope must be transparent. This requires a site that is high and dry. ALMA is thus installed at the 5000m high plateau of Chajnantor in the Atacama Desert -the next best location to outer space for these high-accuracy astronomical observations.
ESO is the intergovernmental European Organization for Astronomical Research in the Southern Hemisphere. On behalf of its thirteen member states ESO operates a suite of the world's most advanced ground-based astronomical telescopes located at the La Silla Paranal Observatory in the Atacama desert in Chile.
The European Southern Observatory (ESO) operates two additional observational sites in the Chilean Atacama. The Very Large Telescope (VLT) is located on Paranal, a 2600 meter high mountain south of Antofagasta. At La Silla, 600 kilometers north of Santiago at 2400 meter altitude, ESO operates several medium-sized optical telescopes.
The Swiss, French and Portuguese astronomers manning the La Silla 3.6m telescope were responsible for the recent discovery of Gliese 581c, an exo-planet that revolves around the star known as Gliese 581, a red dwarf in the Libra constellation. It is older than our solar system and its year lasts only 13 days, since it is 14 times closer to its star than the Earth is to the our Sun. Astronomers also say—based on initial high-tech models and density-mass calculations—this quasi-Earth’s surface is either rocky or ocean-covered—both Earth-like geographical qualities.
Posted by Casey Kazan.
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