ALMA observatory equipped with its first antenna

December 19, 2008
ALMA 12 m diameter antenna, manufactured by Mitsubishi Electric Corporation, pictured at the ALMA Operations Support Facility. Credit: ALMA (ESO/NAOJ/NRAO).

High in the Atacama region in northern Chile, one of the world's most advanced telescopes has just passed a major milestone. The first of many state-of-the-art antennas has just been handed over to the Atacama Large Millimeter/submillimeter Array (ALMA) project. ALMA is under construction on the plateau of Chajnantor, at an altitude of 5000 m. The telescope is being built by a global partnership, including ESO as the European partner.

ALMA will initially comprise 66 high precision antennas, with the option to expand in the future. There will be an array of fifty 12-metre antennas, acting together as a single giant telescope, and a compact array composed of 7-metre and 12-metre diameter antennas.

With ALMA, astronomers will study the cool Universe — the molecular gas and tiny dust grains from which stars, planetary systems, galaxies and even life are formed. ALMA will provide new, much-needed insights into the formation of stars and planets, and will reveal distant galaxies in the early Universe, which we see as they were over ten billion years ago.

The first 12-metre diameter antenna, built by Mitsubishi Electric Corporation for the National Astronomical Observatory of Japan, one of the ALMA partners, has just been handed over to the observatory. It will shortly be joined by North American and European antennas.

"Our Japanese colleagues have produced this state-of-the-art antenna to exacting specifications. We are very excited about the handover because now we can fully equip this antenna for scientific observations," said Thijs de Graauw, ALMA Director.

Antennas arriving at the ALMA site undergo a series of tests to ensure that they meet the strict requirements of the telescope. The antennas have surfaces accurate to less than the thickness of a human hair, and can be pointed precisely enough to pick out a golf ball at a distance of 15 km.

"ALMA is very important to European astronomers and to ESO, the European partner in this project, because it allows us to look at the Universe in a way that has never been possible before. It really marks the start of a new era in astronomy," said Wolfgang Wild, the European ALMA Project Manager.

This antenna handover is a major milestone, as the observatory team can now proceed with integrating the rest of the components, including the sensitive receivers that will collect the faint cosmic signals from space.

The antennas are tested at the Operations Support Facility, at an altitude of 2900 m, before being moved to the plateau of Chajnantor at 5000 m. The Operations Support Facility will also be the observatory's control centre.

ALMA is being built on the Chajnantor plateau, high in the Chilean Andes, because the site's extreme dryness and altitude offer excellent conditions for observing the submillimetre-wavelength signals for which the telescope is designed.

In addition, the wide plateau at Chajnantor offers ample space for the construction of the antenna array, which is spread out and linked together over distances of more than 16 kilometres.

"The ALMA antennas must withstand the harsh conditions at Chajnantor with strong winds, cold temperatures and a thin atmosphere with half as much oxygen as at sea level. This forbidding environment also poses challenges for the workers building ALMA," said de Graauw.

The antennas, which each weigh about 100 tons, can be moved to different positions in order to reconfigure the ALMA telescope. This will be carried out by two custom-designed transporters, each of which is 10 metres wide, 20 metres long, and has 28 wheels.

Source: ESO

Explore further: European ALMA antenna brings total on Chajnantor to 16

Related Stories

European ALMA antenna brings total on Chajnantor to 16

August 1, 2011

The first European antenna for the Atacama Large Millimeter/submillimeter Array (ALMA) has reached new heights, having been transported to the observatory’s Array Operations Site (AOS) on 27 July 2011. The 12-metre diameter ...

ALMA telescope reaches new heights

September 23, 2009

The ALMA (Atacama Large Millimeter/submillimeter Array) astronomical observatory took another step forward and upward, as one of its state-of-the-art antennas was carried for the first time to Chile's 16,500-foot-high plateau ...

Antennas by General Dynamics enable 'early science' for ALMA

October 3, 2011

Thirteen 12-meter antennas manufactured by General Dynamics SATCOM Technologies have been successfully installed at the 16,500-foot-high Chajnantor plateau in Chile, home to the Atacama Large Millimeter/submillimeter Array ...

Major milestone: First two ALMA telescope antennas linked

May 6, 2009

On 30 April, the team observed the first "interferometric fringes" of an astronomical source by linking two 12-metre diameter ALMA antennas, together with the other critical parts of the system. Mars was chosen as a suitable ...

Closing the loop for ALMA

January 4, 2010

On 20 November 2009 the third antenna for the ALMA observatory was successfully installed at the Array Operations Site, the observatory's "high site" on the Chajnantor plateau, at an altitude of 5000 metres in the Chilean ...

Recommended for you

What happens when your brain can't tell which way is up?

October 13, 2015

In space, there is no "up" or "down." That can mess with the human brain and affect the way people move and think in space. An investigation on the International Space Station seeks to understand how the brain changes in ...

Hubble sees an aging star wave goodbye

October 12, 2015

This planetary nebula is called PK 329-02.2 and is located in the constellation of Norma in the southern sky. It is also sometimes referred to as Menzel 2, or Mz 2, named after the astronomer Donald Menzel who discovered ...

What are white holes?

October 9, 2015

Black holes are created when stars die catastrophically in a supernova. So what in the universe is a white hole?

A mission to a metal world—The Psyche mission

October 9, 2015

In their drive to set exploration goals for the future, NASA's Discovery Program put out the call for proposals for their thirteenth Discovery mission in February 2014. After reviewing the 27 initial proposals, a panel of ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.