Astronomers look at over 10 million stars in search for alien life, find nothing

midian182

Posts: 6,648   +59
Staff member
In brief: Keeping in line with the rest of 2020, a large-scale search of over 10 million stars for signs of alien technology has turned up… nothing.

As explained in the study, which was published in Publications of the Astronomical Society of Australia, the Murchison Widefield Array (MWA) in Western Australia was used to examine stars in the Vela region for what could be signs of alien civilizations.

The MWA consists of 4096 spider-like antennas that sit in the ground and listen for "technosignatures," or evidence of alien technology, in a search for extraterrestrial intelligence (SETI).

"The MWA is a unique telescope, with an extraordinarily wide field-of-view that allows us to observe millions of stars simultaneously," said astronomer Chenoa Tremblay, from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR). "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."

Tremblay explained how a radio signal could be identified as coming from an alien civilization: "Think of a car alarm when you leave your lights on, where there are a series of equally spaced 'ping' sounds. The survey looks for a repeating ping that may be escaping noise from a planet or 'a purpose-built signal.'"

This doesn't mean we should give up on ever finding alien life, of course. As Hitchhiker's Guide to the Galaxy author Douglas Adams said, "space is big, you just won't believe how vastly, hugely, mind-bogglingly big it is." The survey was akin to searching for something in an ocean, but only looking at "a volume of water equivalent to a large backyard swimming pool," according to the researchers. Remember, the Milky Way galaxy alone has between 100 billion and 400 billion stars.

Tremblay also noted that the study assumes alien civilizations have technologies similar to our own and that they have developed to the point of using radio waves to communicate. It could also be that any electromagnetic radiation coming from an alien race is too far away or too weak to detect.

New SETI studies will take place in the future using even more powerful telescopes that can survey billions of star systems, so perhaps one day we'll discover that we're not alone in the universe.

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How old is the universe 13.8 billion years? How long have we had radio technology - 150 years? Space isn't just very big, time is also very long. I suspect we will be lucky to find silimar life to ourselves (I.e. intelligent life using radio wave transmitters), that is also nearby, and in the same time period as ourselves. My guess is life existed, and probably existing now somewhere, and will exist in billions and trillions of years into the future, life where systems haven't even been formed yet. But we'll be lucky to find evidence for any of it with our current technology level.
 

cliffordcooley

Posts: 12,690   +6,051
Because it is so easy to see signs that we exist.</endsarcasm> From a neighboring star there would likely be no signs we exist. So by our own definition, that must mean we don't exist.
 

Endymio

Posts: 1,334   +1,216
I believe the basic premise is flawed. Even here on Earth, we are already moving away from high-power long-wavelength narrow-band radio transmissions. We began such a century ago. Less than a century from now, I doubt we'll be emitted any detectable emissions in that category. That's a fairly narrow time window in which to look.
 
Life surely has to be out there! The universe never has one example of anything, so why so, life?

The huge power requirements needed for a transmitter(from aliens) could mean that we can't detect a direct signal because it's too weak, an indirect scatter-gun type signal even weaker. A civilisation with a window in sync with our receiving equipment, could still be there. We have to keep trying with more advanced technology.

 

cliffordcooley

Posts: 12,690   +6,051
The huge power requirements needed for a transmitter(from aliens) could mean that we can't detect a direct signal because it's too weak
Bingo
Light from any star is so weak we can not see it clearly. They all have distortion we like to call a twinkle. And we are supposed to be able to detect some sort of radio transmission. Yeah, I don't think so. Just how strong would a transmission have to be? In order to match the power of a suns light transmission.

A civilisation with a window in sync with our receiving equipment, could still be there. We have to keep trying with more advanced technology.
Until you think about time lag between locations, even with the closest of stars. Can you imagine studying a new language/culture, with a month or more lag between thoughts. We could certainly get trapped in our own errors and never solve the confusion.
 
How old is the universe 13.8 billion years? How long have we had radio technology - 150 years? Space isn't just very big, time is also very long. I suspect we will be lucky to find similar life to ourselves (I.e. intelligent life using radio wave transmitters), that is also nearby, and in the same time period as ourselves. My guess is life existed, and probably existing now somewhere, and will exist in billions and trillions of years into the future, life where systems haven't even been formed yet. But we'll be lucky to find evidence for any of it with our current technology level.
You just got me thinking how incredible it would be to find the archeological remains of an alien species that had gone extinct hundreds of millennia ago...
 

Endymio

Posts: 1,334   +1,216
Light from any star is so weak we can not see it clearly. They all have distortion we like to call a twinkle...
Twinkling is not caused by the light being 'weak', but rather atmospheric turbulence. Move up a hundred miles, outside the earth's atmosphere and the light is just as dim, but the twinkling is nonexistent.

.... And we are supposed to be able to detect some sort of radio transmission. Yeah, I don't think so.
Remember, you're seeing the light of a star with just your naked eye. Some telescope arrays are the equivalent of an "eye" that's twenty miles across: several hundred millions as times as sensitive.
 
Bingo
Light from any star is so weak we can not see it clearly. They all have distortion we like to call a twinkle. And we are supposed to be able to detect some sort of radio transmission. Yeah, I don't think so. Just how strong would a transmission have to be? In order to match the power of a suns light transmission.

Until you think about time lag between locations, even with the closest of stars. Can you imagine studying a new language/culture, with a month or more lag between thoughts. We could certainly get trapped in our own errors and never solve the confusion.
Yeah, I meant that a signal we detect could be millions, or even billions of years old, as the speed of light according to Einstein and pretty much all of his contemporaries, can not be broken. The E-M waves we detect will be in the past and the civilisation who sent a signal could be long dead.

But you are right, a conversation could be impossible due to the lag.
 

JW0914

Posts: 35   +20
Most galaxies contain in excess of 200B stars (10M is ≤0.00005% of stars) and there are ~100B - 200B galaxies, with the universe being 92B light-years across; even if we could travel at the speed of light, all galaxies and stars would be speeding away from us since Space itself is expanding at a faster rate than the speed of light due to dark energy (Space itself is not locked to the speed of light since space has no mass).

Due to Space itself continuing to expand, we will only ever be able to see ~13B light-years in any direction, with the number of galaxies and stars decreasing over time; eventually, we'll be unable to see any since all will be beyond our ~13B light-year boundary of view.
 

Endymio

Posts: 1,334   +1,216
...since Space itself is expanding at a faster rate than the speed of light due to dark energy (Space itself is not locked to the speed of light since space has no mass). Due to Space itself continuing to expand, we will only ever be able to see ~13B light-years in any direction...
To correct a couple points, space is not unbound from relativity because it "has no mass". Light itself, for instance, has no mass-- but it still is limited to the speed of light. Also, the 13.8B LY cosmological horizon will expand over time, in lockstep with the age of the universe.
 

Knifeman

Posts: 13   +4
This is about the SETI and radio search for aliens.
Radio waves? You must be kidding. Have not crossed anyone's mind that Aliens have no need for Radio waves? They simply could communicate by direct mind to mind. Just like many UFO abductors report.
Just like some species here on the Earth communicate - ants are just one example.
How would we, the not so evolved race ever detect that?