The Breakthrough Listen project, which looks for intelligent communications in the universe, has made several attempts to find evidence of extraterrestrial civilizations through radio astronomy. His latest effort has focused attention on the center of our galaxy, the Milky Way. The idea behind Breakthrough Listen is that, if there isalien civilizations
, they probably emit radio signals, either intentionally or not.
Most of their work has focused on stargazing with potentially habitable planets, thinking that just as we emit radio signals, they will too.
But when they have looked at the center of our galaxy, they have started looking for more ambitious aliens.
The central region of our galaxy is a great place to point your telescope if you want to hear signals through thousands of stars.
It is the region of the Milky Way where the stars are most densely packed. The downside is that the center of the Milky Way is outside the galactic habitable zone.
Not the best place Not the best place
For a planetary system, the habitable zone is defined by the distance of a planet from its star. Too close and the water would evaporate, too far and everything would freeze.
Obviously, things are not that simple and life can arise in unexpected places, but that appreciation is a good guide, although approximate.
In principle, it shouldn’t matter where a habitable star system is located in our galaxy, but on cosmic scales it is relevant.
Nearby cataclysmic events, such as supernovae and gamma-ray bursts, could fry life on a young planet.
Since the central region of our galaxy is dense with the kind of large stars that tend to explode, it is likely to be very hostile to life.Related Topic: New Signs of Possible Pre-Human Civilizations
Related Topic: New Signs of Possible Pre-Human Civilizations
Checking … Checking …
However, if you are a galaxy-spanning civilization and want to announce your presence to the universe, then you can place a loud radio transmitter near the center of the galaxy where everyone can hear you. So Breakthrough Listen decided to check it out.
To do this, the team looked for what are known as radio transients – these are short-lived radio bursts that can be caused by things like magnetars and starbursts.
Since most transients occur randomly in the sky, an alien civilization could differentiate itself from them by creating radio bursts with regular periodicity, say at intervals of about a few hours apart.
Using the Green Bank telescope in West Virginia and the Parkes radio telescope in eastern Australia, the team gathered 600 hours of radio observations.
Unsurprisingly, they found no evidence of a repeated alien signal. What’s more, its data is robust enough to rule out repeated signals at roughly 10-hour intervals.
… but not … but not
So the aliens may be playing at longer intervals, but so far it seems they aren’t talking.
Despite the lack of extraterrestrial signals, the study uncovered several transient events.
These events not only help us to understand phenomena such as radiating magnetars, but also to map the distribution of these objects in the central galactic region.
Brian Koberlein is an astrophysicist and writer. This article was originally published on his personal blog under the title Aliens and Other Things. Reproduced with permission.
Aliens and Other Things ReferenceReference
The Breakthrough Listen Search For Intelligent Life Near the Galactic Center I
. Vishal Gajjar, et al. arXiv: 2104.14148 (2021).
Image: Vinícius Taranto on Pixabay.
Eddie is an Australian news reporter with over 9 years in the industry and has published on Forbes and tech crunch.