Murchison Widefield Array, Radio interferometer at Murchison Radio-astronomy Observatory, Western Australia

The Murchison Widefield Array is a radio telescope with 128 antenna tiles at the Murchison Radio-astronomy Observatory in Western Australia. The facility receives radio waves between 80 and 300 megahertz and helps detect some of the universe's earliest light.

The MWA began as a 32-tile prototype (MWA-32T) built and operated between 2007 and 2011 at Mileura Station before moving to Boolardy Station. Phase I reached practical completion in late 2012 and finished commissioning on 20 June 2013, at a cost of A$51 million. Phase II doubled the tiles and was launched on 23 April 2018, and Phase III began in 2022 with the MWAX correlator.

The site draws researchers from around the world who collaborate on understanding the universe's beginnings through radio signals. This international teamwork has shaped how modern radio astronomy is conducted.

The site sits in a protected zone with minimal electromagnetic interference, which means special permission is required to visit. It is best to contact the observatory in advance to arrange access and learn about visiting conditions.

In 2015 undergraduate Cleo Loi used the array to detect plasma tubes in the ionosphere, winning the Astronomical Society of Australia's Bok Prize. The GLEAM survey catalogued 300,000 extragalactic sources at 20 frequencies between 70 and 230 MHz.