The Very Very Large Array

Posted by Sam Churchill on

The Atacama desert in Northern Chile is the driest place on Earth. The dry mountains get an average of less than .004 inches of rain a year. Some places haven’t had rainfall in over 400 years. Blocked from moisture on both sides, by Pacific coastal mountains and by the inland Andes, it is virtually sterile.

In 2003, a team of researchers duplicated the tests used by Viking Mars landers to detect life. They were unable to detect any signs in the Atacama Desert.

Now it’s coming alive.

The world’s largest, most expensive, microwave telescope is now under construction in the Atacama Desert. The ALMA telescope array, to be located at the Llano de Chajnantor Observatory in the Atacama desert in northern Chile, is expected to revolutionise modern astronomy.

Costing some $1.5 billion, the Atacama Large Millimeter Array (ALMA) is an international astronomy project using an array of 64 high-precision, 12-meter antennas.

Construction has begun in Texas (photos). General Dynamics’ SATCOM Technologies will manufacture and deliver 25 antennas for the North American portion of the international ALMA project. The 40 foot dish antennas are among the world’s most sensitive millimeter and sub-millimeter telescopes.

“The ALMA 12-meter antennae will work together as one telescope to provide a resolution 10 times higher than the Hubble Space Telescope,” said Jeff Porter, general manager for General Dynamics. It’s designed to observe galaxies at the edge of the known universe, as well as stars and planets in their formative stages using frequencies between 35 and 850 GHz.

Much of the radiation energy in the Universe is in the millimetre portion of the spectrum. This radiation, say scientists, comes from the cold dust and gas that fills interstellar and intergalactic space. It also comes from distant galaxies and clusters that formed billions of years ago at the edges of the universe.

With ALMA, astronomers will have access to this portion of the spectrum. Superconducting detectors for the millimetre waves will operate at liquid Helium temperatures of -269 °C, amplifing the faint whispers of radiation. A correlator combines all of the data from the 64 antennas to make high resolution images.

Testing has begun. The array should be complete in 5 years.

Extreme Science, Wikipedia and the National Radio Astronomy Observatory have more on the Atacama Large Millimeter Array. The Google Earth Community and Secret Bases profile other interesting facilities.

Posted by Sam Churchill on Thursday, April 27th, 2006 at 10:59 am .

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