Deep into that darkness peering

Mon, 10/10/2011 - 07:44 — Ben Gilliland

In the lifeless desert plains high above Chile, a giant has awoken and opened its eyes for the first time. Its eyes pierce the rarefied Andean atmosphere to cast their gaze into the deepest recesses of the universe and back to the birth of time.

Alma, or Atacama Large Millimetre/submillimetre Array, is a colossus by anyone’s standards. When completed next year, the £840million telescope will consist of 66 radio antennae spread across the Atacama Desert, which, by working together, will have the radiation-gathering ability of a telescope measuring a titanic 10km wide.

At the moment, just 19 of Alma’s antennae are installed and operational, but scientists are already getting a taste of the array’s potential, which will eventually exceed that of the mighty Hubble Space Telescope by a factor of ten.

[Image: Above: Alma’s first image. These are the Antennae Galaxies, which are two Milky Way-like galaxies that collided a few hundred million years ago. As they merge, clouds of gas smash together and collapse – creating new stars. Although Hubble’s visible light images (right) reveal the newborn stars and galaxies, Alma sees in wavelengths (left) that reveal the clouds of dense cold gas from which new stars and galaxies form. Click image to galacticate]

The Atacama is one of the driest places on Earth and, combined with the razor-thin atmosphere found at 5,000m (16,500ft) above sea level, it is perfect for peering deep into the cosmos.

Unlike optical telescopes such as Hubble, which study the visible part of the electromagnetic spectrum, Alma is tuned to see radiation in the much longer far-infrared and sub-millimetre wavelengths.

This will allow the telescope to detect extremely cold objects, such as the clouds of gas from which the stars and galaxies are formed, which are normally outshone by the universe’s more flamboyant inhabitants.

It will also be able peer at the most distant objects of the cosmos – opening a sort of window through time that will allow scientists to study the universe’s first inhabitants.

The project’s technical achievements are impressive. Parts of the device need to be super-cooled to within a fraction of a degree of absolute zero (-273°C or -459°F) so that none of the precious data collected by the array is lost to electrical interference.

Once operating at full capacity, the data gathered by Alma will be impressive – some 96gigabits a second, processed by a computer operating at 17million billion calculations a second, which will be combined to provide images ten-times clearer than even the legendary Hubble can churn out.

Alma is a joint venture between the European Southern Observatory, the National Science Foundation (America), the National Research Council of Canada and the National Astronomical Observatory of Japan.

 

via cosmonline.co.uk