People have been looking up at the night sky for thousands of years but radio astronomy was new in the 1950s. One of the first fully functioning radio telescopes in the Southern Hemisphere was the one at Parkes Observatory. It is located 20 kilometres (12.4 miles) north of the town of the same name and about 380 kilometres (236 miles) west-northwest of Sydney. It has a long history of scientific achievements and was crucial in NASA’s mission to put the first man on the Moon.
CSIRO Radiophysics Chief Edward ‘Taffy’ Bowen campaigned heavily for the radio telescope. It took three years to design and the final blueprint was prepared by Freeman Fox and Partners, the company had a hand in the creation of the Sydney Harbour Bridge. While the designing process was going on, another team were working on finding a location for the observatory. Initially 30 possible sites were proposed but in the end it came down to just two, Parkes and a place in the Blue Mountains. The one major requirement was the site had to have low radio emissions. Parkes was selected in March 1958 and CSIRO purchased 70 hectares (172 acres) from farmer Australia ‘Austie’ Helm. The observatory took three years to build and was officially opened on October 31st, 1961.
Parkes Observatory was put to work right away. The telescope helped to track Mariner 4 as it became the first spacecraft to successfully reach Mars and take close up pictures of its surface. It aided NASA on Voyager 2’s flybys of Uranus in 1986 and Neptune in 1989. Voyager 2 remains the only probe to visit the two planets. The telescope was also involved in the ESA’s Giotto spacecraft encounter with Halley’s Comet, the Galileo spacecraft’s mission to Jupiter and the Cassini-Huygens mission to Saturn. In 2005, Cassini spacecraft released the Huygens probe and it descended towards the moon Titan. Huygens sent back the first images of Titan’s surface and no other such landing has been attempted so far from Earth. The telescope is also responsible for discovering over 700 pulsars during its operation, as well as a rare double-pulsar system in 2003. A pulsar is the spinning dense remains of a dead star that sends electromagnetic beams out into space. Astronomers pick up these beams as blinks. Think of a pulsar as the lights of a lighthouse, on a dark night, and astronomers are the crew of the ship looking at the lights.
The Parkes Observatory is most famous for its involvement with the Apollo 11 mission to the Moon in 1969. Because Neil Armstrong decided to do the moonwalk ahead of schedule, the first eight minutes of footage was received by the radio observatories in Honeysuckle Creek (close to Canberra) and Goldstone, California. Once Parkes had moved into range, the rest of the transmission was received there. For safety reasons, the 64 meter (210 foot) dish cannot experience winds greater than 35 kilometres (22 miles) per hour and is stored facing skywards. The telescope experienced winds over 100 kilometres (62 miles) per hour during the broadcast. Its structure was put under great pressure but, luckily, didn’t suffer any permanent damage.
The radio telescope was used on all manned-Moon missions, except Apollo 16. It was vital in picking up Apollo 13’s weak radio signals after it suffered an oxygen tank explosion in 1970. The situation became dire but the three men did return safely to Earth.
The events of the Apollo 11 mission at Parkes Observatory were somewhat fictionalised in The Dish (2000). Unlike in the movie, the observatory never lost communication with the spacecraft and there were dozens of people in the control room, not just the four characters featured. During the cricket match scene on the dish itself, the cast used a tennis ball. A real cricket ball would’ve damaged the telescope’s surface.
The Parkes telescope has received many upgrades over the years to keep it on the forefront of radio astronomy research. It is now 10,000 times more sensitive than when it first started operation in 1961 and can now pick up the most distant and faintest signals. It has the strength to easily pick up a mobile phone signal as far away as Pluto, 7.5 billion kilometres (4.67 billion miles). The telescope has been that successful that NASA used the design for the radio telescopes at the Canberra Deep Space Communication Complex. The observatory is a key part of Breakthrough Listen. The project’s leaders have organised many high-profile radio observatories, from all over the world, to participate in the largest ever search for alien civilisations beyond the Solar System. It is also the fourth most used radio telescope in the world with over 300 researchers using the facilities each year, 40% of which are international. Over 100,000 tourists visit the location each year too. It operates 24 hours a day, every day of the year.
This article was originally posted on the now defunct Science Niche website on January 13th, 2019.
References:
5 things you didn’t know about the Parkes radio telescope (https://blog.csiro.au/5-things-you-didnt-know-about-the-parkes-radio-telescope/)
Breakthrough Listen (Pamphlet). CSIRO Astronomy and Space Science.
Dish, The (Booklet). CSIRO Astronomy and Space Science.
Parkes radio telescope and the Apollo 11 Moon landing (https://csiropedia.csiro.au/parkes-radio-telescope-and-the-apollo-11-moon-landing/)
Parkes Radio Telescope – Fast Facts, The (Pamphlet). CSIRO Astronomy and Space Science.
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