25 July, 2003
ALMA is a joint project between North America and Europe to build and operate the world’s largest, most powerful telescope operating at millimeter and sub-millimeter wavelengths.
In North America, the National Science Foundation (NSF) executes the project through the National Radio Astronomy Observatory (NRAO), which is operated under cooperative agreement by Associated Universities, Inc. (AUI). The National Research Council of Canada will partner with the NSF in the North American endeavor. In Europe, ESO is leading on behalf of its ten member countries and Spain.
This action by the Chilean government marks a significant milestone for ALMA by providing a site capable of meeting all the stringent scientific demands of this telescope.
The ALMA partners now have the necessary approval to begin construction of the infrastructure and facilities needed for the telescope. Prototypes of the antennas to be used for the telescope are already undergoing evaluation at the NRAO’s Very Large Array facility near Socorro, New Mexico.
To help mark the significance of this event, following the ceremony, work began immediately on the access road that the ALMA partners will use to transport materials, supplies, and personnel to the site, in preparation for the groundbreaking and full-scale construction to take place later this year.
Previously, Chile had issued a Presidential decree granting AUI permission to work on the ALMA project and signed an agreement between ESO and the government of the Republic of Chile. These actions by the government of Chile were necessary formal steps leading to the official granting of the site, which was set aside for use by the ALMA partners for no less than 50 years. This arrangement also ensures that Chile will retain the long-term ownership of the area, a significant detail because of the strong national pride in this region of the country.
The ALMA site was selected because millimeter and sub-millimeter electromagnetic radiation is absorbed by moisture in Earth’s atmosphere. To conduct research in this critical portion of the spectrum, astronomers needed a site that is very dry, and preferably at a very high altitude. Extensive tests showed that the sky above the Atacama Desert at 5000 meters (16,500 feet) has the unsurpassed clarity and stability for ALMA.
The millimeter wavelengths that ALMA will study cross the critical boundary between infrared and microwave radiation. This portion of the spectrum holds the key to understanding such processes as planet and star formation, the formation of early galaxies and galaxy clusters, and the detection of organic and other molecules in space.
When complete in 2012, ALMA will be an array of 64, 12-meter radio antennas that will work together as one telescope. Astronomers are anxious to have access to ALMA, because this portion of the electromagnetic spectrum has never been studied with the remarkable sensitivity and resolution that ALMA will provide.
Also as part of the agreement, the ALMA partners will contribute $700,000 annually to Chile for the duration of the concession. These funds will finance local and regional projects, and scientific development at the national level.