A windy day in July
On July 21, 1969 (AEST), the Parkes Observatory faced a crisis. A series of 110 km/h wind gusts struck the 64-metre telescope, pushing it past its safety limits while it was tilted over, waiting for the Moon to rise. Inside, operators felt the control room shudder, but they held their position. They were on contract with NASA to help broadcast the Apollo 11 moonwalk, and the world was waiting.
The original mission plan had NASA's own antennas at Goldstone, California, and Honeysuckle Creek, Australia, as the primary receivers. But the astronauts started their moonwalk early, changing the geometry of the broadcast. For the first few minutes, NASA switched between the signals from Goldstone and Honeysuckle Creek. Once the Moon cleared the horizon at Parkes, its powerful signal proved to be of such superior quality that Houston controllers selected it and stayed with it for the remaining two and a half hours of the broadcast. The images that a global audience of 600 million people saw of Neil Armstrong and Buzz Aldrin exploring the lunar surface came via this dish in the middle of a New South Wales sheep paddock.
A pulsar-hunting machine
Built between 1959 and 1961, the Parkes telescope—also known by its Wiradjuri name, Murriyang—is a 1,000-tonne steerable dish. Its design was so successful that NASA copied it for the dishes of its Deep Space Network. While its role in the Apollo program brought it popular fame, its scientific work is extensive. The observatory has been responsible for discovering more than half of all known pulsars—rapidly spinning neutron stars that emit beams of radio waves.
In 2007, an analysis of archival data from 2001 led to the discovery of the first Fast Radio Burst (FRB), a short, intense pulse of radio waves from deep space. The telescope is a component of the International Pulsar Timing Array, a project that uses pulsars to detect gravitational waves. It also participates in the Breakthrough Listen project, a large searches for extraterrestrial intelligence. Parkes has tracked numerous interplanetary missions, including Mariner 2's flyby of Venus in 1962, the Galileo mission to Jupiter, and the Huygens probe's landing on Saturn's moon Titan. Over decades of upgrades, the telescope is now 10,000 times more sensitive than when it was first built.