We can never prove that we’re alone in the universe. But a remote radio observatory in Australia’s outback with the ability to scan hundreds of times more broadly than any previous search for extraterrestrial life, could prove that we’re not. “The search will continue”, said Edwin Hubble, for whom the iconic space telescope was named, about our quest to unveil the ultimate secret of the cosmos. “The urge is older than history. It is not satisfied and will not be suppressed.”
Astronomers used the Murchison Widefield Array telescope (MWA) –which recently discovered the largest known eruption in the universe since the Big Bang–with an extraordinarily wide field-of-view that observes millions of stars simultaneously. The MWA scanned 10 million stars around the constellation of Vela for 17 hours, looking for the the presence of an intelligent source more than 100 times broader and deeper than ever before. And came up empty.
The study observed the sky around the Vela constellation. But in this part of the Universe at least, it appears other civilizations are elusive, if they exist. The research was conducted by CSIRO astronomer Dr Chenoa Tremblay and astrophysicist Steven Tingay, from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR).
Tremblay said the telescope was searching for powerful radio emissions, technosignatures’, at frequencies similar to FM radio frequencies. “With this dataset, we found no technosignatures–no sign of intelligent life.”
This NASA APOD mosaic shows the northwestern edge of the constellation Vela (the Sails), centered on the glowing filaments of the Vela Supernova Remnant, the expanding debris cloud from the death explosion of a massive star. Light from the supernova explosion that created the Vela remnant reached Earth about 11,000 years ago. (Robert Gendler, Roberto Colombari, Digitized Sky Survey)
Exploring an Eight-Dimensional Search Space
Tingay said even though this was the broadest search yet, he was not shocked by the result. “As Douglas Adams noted in The Hitchhikers Guide to the Galaxy, ‘space is big, really big’ and even though this was a really big study, the amount of space we looked at was the equivalent of trying to find something in the Earth’s oceans but only searching a volume of water equivalent to a large backyard swimming pool. Since we can’t really assume how possible alien civilizations might utilize technology, we need to search in many different ways. Using radio telescopes, we can explore an eight-dimensional search space.
“Although there is a long way to go in the search for extraterrestrial intelligence, telescopes such as the MWA will continue to push the limits–we have to keep looking.”
Coming Attraction -Earth-like Radio Signals
The MWA is a precursor for the instrument that comes next, the Square Kilometre Array (SKA), a 1.7 billion Euro observatory with telescopes in Western Australia and South Africa. To continue the Douglas Adams references, think of the MWA as the city-sized Deep Thought and the SKA as its successor: the Earth.
“Due to the increased sensitivity, the SKA low-frequency telescope to be built in Western Australia will be capable of detecting Earth-like radio signals from relatively nearby planetary systems,” said Tingay. “With the SKA, we’ll be able to survey billions of star systems, seeking technosignatures in an astronomical ocean of other worlds.”
The MWA is located at the Murchison Radio-astronomy Observatory, established and maintained by CSIRO–Australia’s national science agency. The SKA will be built at the same location but will be 50 times more sensitive and will be able to undertake much deeper SETI experiments.
The Daily Galaxy, Jake Burba, via International Center for Radio Astronomy
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