Timeline

ALMA through the years

The birth of ALMA dates back to the end of the last century. Large millimeter/submillimeter array radio telescopes were studied by astronomers in Europe, North America and Japan and different possible observatories had been discussed. After thorough investigations, it became obvious that the ambitious projects of all of these studies could hardly be realized by a single community.

Consequently, a first memorandum was signed in 1999 by the North American community, represented through the NSF (National Science Foundation), and the European community, represented through ESO (European Organisation for Astronomical Research in the Southern Hemisphere), followed in 2002 by an agreement to construct ALMA on a plateau in Chile.

Thereafter, Japan, through the NAOJ (National Astronomical Observatory of Japan), worked with the other partners to define and formulate its participation in the ALMA project. An official, trilateral agreement between ESO, the NSF, and the National Institutes for Natural Sciences (NINS, Japan) concerning the construction of the enhanced Atacama Large Millimeter / submillimeter Array was signed in September 2004. This agreement was subsequently amended in July 2006.

NAOJ will provide four 12-meter diameter antennas and twelve 7-meter diameter antennas for a compact array (ACA), the ACA correlator and three receiver bands. With the inclusion of the Asian partners, ALMA has become a truly global astronomical facility, involving scientists from four different continents.


  • 1995
  • NRAO/ESO/NAOJ joint site testing with Chile
  • 1999
  • June
    U.S. / European Memorandum of Understanding for Design & Development
  • 2001
  • April
    Resolution for ALMA between Europe, North America and Japan
  • 2003
  • February
    North American / European ALMA Bilateral Agreement. This agreement was subsequently amended in February 2007.
    Read more
  • April
    Testing of first prototype antenna begins at the ALMA Test Facility (ATF) site in New Mexico
  • November
    Groundbreaking ceremony at ALMA site.
    Read more
  • 2004
  • September
    Agreement concerning the construction of the enhanced Atacama Large Millimeter / submillimeter Array, between ESO, NSF and NINS. This agreement was subsequently amended in July 2006
  • 2005
  • January
    Japanese contract for ACA production antennas
  • July
    North American contract for up to 32 ALMA production antennas
  • December
    European contract for up to 32 ALMA production antennas
  • 2007
  • March
    First fringes detected by two linked antennas at the ATF.
    Read more
  • April
    Arrival of first antenna in Chile
  • 2008
  • February
    Arrival of the two ALMA transporters in Chile.
    Read more
  • July
    First antenna movement with a transporter.
    Read more
  • October
    Installation of a Front End produced in North America in one of the Japanese antennas.
    Read more
  • December
    Acceptance of the first ALMA antenna.
    Read more
  • 2009
  • May
    First interferometry with two antennas at the Operations Support Facility.
    Read more
  • September
    First move of an ALMA antenna to Chajnantor.
    Read more
  • November
    Phase closure with three antennas at Chajnantor.
    Read more