Astronomers using the Murchison Widefield Array (MWA) radio telescope have searched for technosignatures — indicators of advanced extraterrestrial civilizations — in six known exoplanets and over 10 million stellar systems in the Vela region of our Milky Way Galaxy. But in this part of the Milky Way at least, it appears alien civilizations are elusive, if they exist.
Tremblay & Tingay report a new large-scale survey towards the Vela region of the Milky Way. Image credit: NASA.
“The MWA is a unique telescope, with an extraordinarily wide field-of-view that allows us to observe millions of stars simultaneously,” said Dr. Chenoa Tremblay, an astronomer at the CSIRO Astronomy and Space Science.
Dr. Tremblay and her colleague, Professor Steven Tingay from the Curtin University node of the International Centre for Radio Astronomy Research, searched for narrow-band signals consistent with radio transmissions from six known exoplanets (HD 75289b, HD 73526b, HD 73526c, HD 70642b, DE0823-49b and KELT-15b) and 10,355,066 stellar systems in the Vela region.
“The telescope was searching for powerful radio emissions at frequencies similar to FM radio frequencies, that could indicate the presence of an intelligent source,” she explained.
“We observed the sky around the constellation of Vela for 17 hours, looking more than 100 times broader and deeper than ever before.”
“With this dataset, we found no technosignatures — no sign of intelligent life.”
Dipole antennas of the Murchison Widefield Array in Australia. Image credit: Dragonfly Media.
“Even though this was the broadest search yet, we were not shocked by the result,” Professor Tingay said.
“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,” he said.
“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.”
The team’s paper appears in the Publications of the Astronomical Society of Australia.
_____
C.D. Tremblay & S.J. Tingay. A SETI survey of the Vela region using the Murchison Widefield Array: Orders of magnitude expansion in search space. Publications of the Astronomical Society of Australia, published online September 7, 2020; doi: 10.1017/pasa.2020.27
