Mullard Radio Astronomy Observatory

Mullard Radio Astronomy Observatory

One antenna of the One-Mile Telescope at the observatory
The foundation plaque

Mullard Radio Astronomy Observatory (MRAO) is home to a number of large aperture synthesis radio telescopes, including the One-Mile Telescope, 5-km Ryle Telescope, and the Arcminute Microkelvin Imager. Radio interferometry started in the mid-1940s on the outskirts of Cambridge, but with funding from the Science Research Council and a donation of £100,000 from Mullard Limited, construction of the Mullard Radio Astronomy Observatory commenced at Lord's Bridge,[1] a few kilometres to the west of Cambridge. The observatory was founded under Martin Ryle of the Radio-Astronomy Group of the Cavendish Laboratory, University of Cambridge and was opened by Sir Edward Victor Appleton on 25 July 1957. This group is now known as the Cavendish Astrophysics Group.

The site is located at Lord's Bridge, Cambridgeshire on a former ordnance storage facility, next to the now-abandoned Cambridge-Bedford railway line. A portion of the track bed of the old line, running nearly East-West for several miles, was used to form the main part of the "5km" radio-telescope and the Cambridge Low Frequency Synthesis Telescope.


  • Telescopes 1
  • Gallery 2
  • References 3
    • Notes 3.1
    • Sources 3.2


Telescope Year built Status
Arcminute Microkelvin Imager Large Array 2007 Active
Arcminute Microkelvin Imager Small Array 2004 Active
Very Small Array (moved to Tenerife in 1999) 1998 Active
Cosmic Anisotropy Telescope made first high-resolution maps of Cosmic Microwave Background fluctuations 1995 Decommissioned
Cambridge Optical Aperture Synthesis Telescope (COAST) first aperture synthesis at optical wavelengths 1993 Operated on clear nights
One receiver from the MERLIN array 1990 Active
Cambridge Low Frequency Synthesis Telescope (CLFST) 1980 Decommissioned
Ryle Telescope (formerly 5-Kilometre Telescope) 1971 Decommissioned
(repurposed for AMI LA in 2006)
Half-Mile Telescope 1968 Decommissioned
Interplanetary Scintillation Array discovered first pulsar 1967 Decommissioned
One-Mile Telescope 1964 Decommissioned
4C Array, first telescope at the Cambridge's new observatory, used to make the 4C catalogue 1958 Decommissioned


The following photographs were taken in June 2014:



  1. ^ "Subterranea Britannica - Lord's Bridge". 


  • The Mullard Radio Astronomy Observatory webpage
  • Image from Google maps showing the One-Mile, Half Mile, 4C Array, MERLIN, COAST, CAT and Ryle telescopes.
  • Subterranea Britannica entry for Lord's Bridge Forward Filling Depot (also Air Ammunition Park)
  • Subterranea Britannica entry for Lord's Bridge Station