The moon and Canberra’s contribution to that momentous landing 50 years ago was the focus at the end of July, 2019, but the chance to pick up alien signals could well come from another space observatory in our backyard.
Ensconced in a lonely valley near tiny Hoskinstown, about 40kms from the capital, is the Molonglo Observatory Synthesis Telescope: MOST. For more than half a century, it’s scanned the skies, capturing the most mysterious phenomena in the cosmos. Following multi-million dollar upgrades over the last decade, it’s now fittingly referred to as UTMOST.
While many think the radio telescope at Parkes - made famous by the movie, The Dish - is big at 64m diameter, MOST is the largest antenna of its kind in the southern hemisphere. And it’s not so much a “dish” as a “big steel cross.”
Its huge cylindrical “arms”, consisting of thousands of independent antennae, extend almost a kilometre each. With five times the collecting area of Parkes (more than 18,000m2), it can search great swathes of the heavens.
Opened in late 1965 and completed two years before Neil Armstrong made that step onto the lunar surface and into history in 1969, MOST continues to be a hotspot for radio astronomy.
Operated by the University of Sydney, the locally-based telescope looks for some of the “strangest objects in the universe.” In doing so, it produces information critical to the study of things such as black holes. It also allows for the better understanding of fundamental theories, including Einstein’s Relativity (I’m no rocket scientist but, at its most basic, the impact of space and time on each other; alternatively, try to grasp what’s going on in the movie Interstellar).
Radio waves in space were discovered as recently as 1932, by an engineer working for Bell Telephone in the US. Five years later, the first parabolic “dish” antenna - at just 9m - was built by American radio and astronomy amateur, Grote Reber (he moved to Tasmania in 1954).
The design of the Molonglo Telescope was based on the pioneering work of Reber and such an influence was he, a memorial out there contains some of his ashes (as do other observatories throughout the world).
Given the distance of astronomical radio sources - planets, stars, nebulas and galaxies - the equipment had to become larger and more sensitive. This also accounts for why they’re built so far from people: they need to avoid interference from other electronic devices.
[NB: There was some controversy in 1971 with the Yarrowlumla Shire Council of the time looking at a nearby subdivision that would have “put the whole telescope out of operation.”]
In 1954, the innovative Mills Cross Telescope was conceived by CSIR(O) engineer and later Professor of Astrophysics, Bernard Mills. Built near a disused WWII air strip, 40kms west of Sydney, in three short years, it was to become “one of the world’s leading radio astronomy field stations.” The operational parameters of its first telescope - the 450m long arms providing high resolution and a greater ability to detect weak signals - were described as “remarkable.” Notably, it would conduct a detailed survey revealing numerous “extragalactic” radio emissions - that is, from beyond our Milky Way. Closed in 1988, sadly, little remains except for rusting aerials and small telescope dishes.
With much clamour for even larger antennas, a “Super Cross” Telescope was constructed outside Canberra, also by Mills, at a cost of almost a million dollars (around $13mill today). Described as “the most advanced radiotelesope of its kind in the world”, it consisted of north-south and east-west arms. The latter of these would be modified in 1978 to become MOST. After 40 years, the former has only recently been re-employed. Other large cross-type radio telescopes were later built in Italy, Russia and Ukraine.
Involved in some serious research into the unknown in galaxies near and far, one of MOST’s major coups has been the first-time detection of the moment a supernova erupted: SN1987A, the closest observable exploding star in four centuries (Kepler’s Star in 1604, the last), and visible from the southern hemisphere.
Supernovas are the end of a massive star’s life - and when I say massive, that’s as much as eight times the mass of the sun. And the end of its life means its run out of the fuel it needs to sustain itself (to really cheer you up, what astronomers say will eventually happen to that radiant orb in our sky - though it will expand as a “red giant” to likely obliterate us) - and 1987A confirmed this. The remnants, neutron stars, are the densest, directly observable objects known.
Rapidly rotating, highly magnetized versions of these relics - think half a million times the earth’s mass in a sphere the size of small city - are called pulsars. They emit regular, focused beams of radiation detectable as radio pulses and the first in the southern hemisphere were discovered by the Molonglo Telescope the year after it commenced operations.
Between 1967 and 1978, more than half the known pulsars of the time were located by it. Now MOST’s primary work is to observe pulsars and magnetars - another type of neutron star and the most magnetic objects in the universe. (Typically, a neutron star has a magnetic field trillions of times that of the Earth's. In a magnetar, the magnetic field is 1000 times stronger.)
In 1994, MOST was also involved in the capture of information on the closest black hole to earth - GRO J1655-10.
Then there’s MOST’s job detecting another of “astronomy’s biggest puzzles” - fast radio bursts (FRBs). Potentially a million times further away than pulsars, these intense, “brief cosmic blips”, last mere milliseconds. So elusive are they, in the first decade after their 2007 discovery (from archival data collected by the Parkes Observatory), less than 20 were identified. The importance of the still unexplained events could lead to revelations on the composition and weight of the universe.
Heavy stuff indeed.
In conjunction with other organisations and universities, the ongoing program to search for them has resulted the 2018 capture of one of the “most energetic FRBs ever detected” - as the energy they produce in a single burst is the equivalent of the output of the sun in a whole day, you get the idea.
A current project setting records for real-time searches for all of this phenomena has also been given yet another adorable acronym: SMIRF (Survey for Magnetars, Intermittent pulsars, Rotating radio transients and FRBs). It allows for a sweep of the entire southern arc of the Milky Way every 10 days as opposed to once a decade. The volume of information collected means the facility’s recently introduced supercomputers conduct 250 trillion calculations a second, processing a billion gigabytes of data in a year.
Parkes is one of the telescopes employed as part of SETI - the scientific search for extraterrestrial intelligence - and Breakthrough Listen, the most comprehensive search for alien communication using radio wave and light observations. Perhaps though, given the incredible work going on down a backroad in Capital Country, just like those first minutes of footage from the moon landing, the next world-stopping moment from space will come from Canberra.
- for more on Canberra and deep space, https://anoverallview.wixsite.com/blog/post/canberra-s-50-years-of-deep-space.
SOURCES:
http://www.atnf.csiro.au/news/newsletter/jun02/Flowering_of_Fleurs.htm
https://www.smh.com.au/national/engineer-a-star-of-astronomy-20110520-1ewo0.html
https://drive.google.com/viewerng/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxtb2xvbmdsb3BpeHxneDoxNjYyMzVlZGQ2OGVmMzQ0
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