A team of three Australian researchers went on a hunt for aliens in the heart of the Milky Way using one of the world’s most sensitive radio telescopes. In late 2020, they turned their ears to the galactic center, listening for alien techno-tracks. Their field of view contained 144 known exoplanets and potentially billions of stars.
But after more than seven hours of listening to the sky, they say they haven’t found anything that looks alien.
The search was carried out using the Murchison Widefield Array, which consists of 4,096 spider-like antennae webs placed in the Western Australian desert. The antennas, arranged in 256 tiles, can track low-frequency radio waves from space. More importantly, the array’s wide field of view means researchers can listen to techno-traces (signals broadcast by intelligent life) across a huge stretch of space.
A new article accepted for publication in the Publications of the Astronomical Society of Australia describes this quest.
This isn’t the first time the team has used MWA to search for alien signals. Previously in 2020 they analyzed more than 10 million stars by examining the dark forest of the cosmos using MWA, in 2013 they studied the galactic center, and in 2018 they conducted a search towards the Orion Nebula. No alien voices were heard in all three of these inspections.
But the new research differs in a few key ways, said Chenoa Tremblay, a SETI Institute researcher in California and lead author of the new paper. While the previous search of the galactic center in 2013 found only 38 known exoplanets, the new search included 144 exoplanets. “This is the largest known exoplanet population of the four studies we’ve done with the MWA,” Tremblay says.
The search for life around the galactic center is particularly important; because the region contains the highest density of stars in our galaxy. Where there are stars, there may be planets, and planets may contain alien life.
Accurately estimating the amount of stars in the new search is difficult because the galactic center can be very dusty, obscuring the search’s view, making an accurate reading difficult. Previous searches have used data from the Gaia Space Observatory to count the amount of stars, but this system cannot be used in the galactic center.
Tremblay says the team used a different lookup known as the Galactic Core, which classifies 3.3 million stars. However, the review covers less than 1% of the area surveyed by the MWA.
“If we extend this estimate, we cover billions of star systems all the way to the center of our galaxy,” Tremblay says.
27297
