Post by Andrei Tchentchik on Sept 3, 2020 15:25:44 GMT 2
(.#509).- This large French telescope will seek ET’s signals.
This large French telescope will seek ET’s signals.
The Nançay observatory will scan around fifty stars and galaxies in search of a needle in an ocean of hay.
By Grégory Rozières
NANÇAY RADIOASTRONOMY STATION
This large French telescope will seek extraterrestrial signals
SPACE - Somewhere in France, halfway between Orléans and Bourges, the Grand radio telescope of Nançay scans the stars. And in a few weeks, at the start of the new school year, he will begin to observe around fifty stars in search of an artificial, extraterrestrial signal from space.
It was the University of Berkeley, as part of the Seti extraterrestrial intelligence research program, which obtained observation time available on the French radio telescope, the 4th largest in the world.
"What we're going to look for are technosignatures, radio signals that don't seem natural," said Greg Hellbourg, astronomer who oversees the project at the American university, to the HuffPost.
The radio telescope will observe 52 stars within a radius of 33 light years around the Earth, as well as a dozen nearby galaxies. The telescope will scan each star for 20 minutes. Over 6 months, the researchers will have collected 35 hours of observation.
Stars, galaxies and civilizations
From these stars, researchers would like to detect signals proving the existence of extraterrestrial civilizations technologically at least as advanced as Earth. "We have calculated the minimum power that a transmitter should have on the stars scrutinized so that we can receive it," said Greg Hellbourg. And the result is not far from our most powerful transmitters today.
One could even imagine detecting signals coming from species having conquered their star system and harnessed the energy of their star. Even very advanced civilizations, having colonized an entire galaxy.
It may sound crazy, but researchers have in the past categorized the technological level of possible extraterrestrials according to their energy consumption and their expansion in space. This is called the Kardachev scale. It has 3 levels: type 1 civilization consumes the equivalent of the energy produced by its planet, one of type 2 all the energy produced by its star and one of type 3 by all the stars of its galaxy .
Also, don't start dreaming of aliens. To tell the truth, Greg Hellbourg himself does not really believe that the Nançay radio telescope will find anything.
"The search for an unknown signal is extremely complex, and despite the excellent technical capabilities of the radio telescope, we will only explore a tiny part of the parameter space that can be explored."
- Greg Hellbourg
And that's why he judges this important experience.
An old quest ...
It is actually part of a larger program, launched in 2015 by a Russian billionaire and the famous physicist Stephen Hawking: Breakthrough Listen. The idea: unlock a budget of $ 100 million over 10 years to allow Seti researchers to conduct this experiment.
For the time being, researchers at the University of Berkeley, partly funded by this program, mainly used two telescopes. If Nançay's test is successful, the Breakthrough Listen could free up more funds to scan many, many more stars.
The search for extraterrestrials dates from long before this project. Seti was founded in the 1960s, at the start of the space age. Since then, he has been trying, in a way, to respond to the Fermi paradox: given the size and age of the universe, it is highly unlikely that we are the only intelligent species on so many billions of worlds. But then where are they all?
As you know, the Seti has not found anything yet. And since the late 1990s, funding has become scarce.
In fact, the Nançay radio telescope was used in the 1980s to search for extraterrestrial signals by the University of Berkeley, a pioneer in the field. In 1991, Jill Tarter (who co-founded the Seti and who is interpreted by Jodie Foster in the film "Contact") published a study explaining that the various French observations had given nothing.
So why start again? "Technology has evolved a lot, as has computer processing of data," says Greg Hellbourg. We can now observe more stars and radio waves on many more frequencies, all analyzed using very efficient algorithms to process heaps of data.
A drop in the ocean
However, the chances of finding a signal are objectively extremely low, for several reasons. The main thing is that we only observe a tiny part of the sky. At a well-defined point in time, during which a hypothetical civilization would emit a signal.
There are also other problems. For this test at the Nançay observatory, the radio telescope will scan on very specific frequencies. "We don't know of any natural astronomical source that emits such a fine", explains Greg Hellbourg. So logically, if a civilization wanted to signal its presence, it would surely use a frequency which cannot be parasitized by the celestial objects which populate the universe.
But the choice is still far too important. "We have therefore chosen frequencies which refer to molecules linked to life, involving for example carbon or oxygen", specifies the Berkeley researcher. Again, the idea is to say that if an extraterrestrial civilization wants to make itself known, it will put the odds on its side.
Straw and beam
The researchers then demonstrated a form of assumed anthropomorphism. Nothing tells us that life is necessarily made of carbon. That she necessarily needs oxygen. Let it communicate with radio waves. That she simply wants to communicate.
But this ocean is so gigantic and the glass at our disposal so tiny that we have to start somewhere. Besides, Greg Hellbourg does not think that the solution will come from the frequencies currently studied. "I think the signal that we will eventually find will be a broadband signal, because there will be information in it."
So why haven't we found aliens yet? Perhaps the chances of us being alone in the observable universe are actually quite high, as two researchers recently claimed. Perhaps there is another explanation, like those mentioned in the video above.
Perhaps we just haven't looked around enough stars. And perhaps we did not search with the right tools, with the right look. "The pulsars have always been there, we have always captured them with our telescopes. It is a somewhat strange processing of the data already recorded which allowed us to detect one for the first time. Now that we know this method , we've discovered thousands of pulsars. I think it will be the same with the aliens, "Greg Hellbourg hopes.
F I N .
This large French telescope will seek ET’s signals.
The Nançay observatory will scan around fifty stars and galaxies in search of a needle in an ocean of hay.
By Grégory Rozières
NANÇAY RADIOASTRONOMY STATION
This large French telescope will seek extraterrestrial signals
SPACE - Somewhere in France, halfway between Orléans and Bourges, the Grand radio telescope of Nançay scans the stars. And in a few weeks, at the start of the new school year, he will begin to observe around fifty stars in search of an artificial, extraterrestrial signal from space.
It was the University of Berkeley, as part of the Seti extraterrestrial intelligence research program, which obtained observation time available on the French radio telescope, the 4th largest in the world.
"What we're going to look for are technosignatures, radio signals that don't seem natural," said Greg Hellbourg, astronomer who oversees the project at the American university, to the HuffPost.
The radio telescope will observe 52 stars within a radius of 33 light years around the Earth, as well as a dozen nearby galaxies. The telescope will scan each star for 20 minutes. Over 6 months, the researchers will have collected 35 hours of observation.
Stars, galaxies and civilizations
From these stars, researchers would like to detect signals proving the existence of extraterrestrial civilizations technologically at least as advanced as Earth. "We have calculated the minimum power that a transmitter should have on the stars scrutinized so that we can receive it," said Greg Hellbourg. And the result is not far from our most powerful transmitters today.
One could even imagine detecting signals coming from species having conquered their star system and harnessed the energy of their star. Even very advanced civilizations, having colonized an entire galaxy.
It may sound crazy, but researchers have in the past categorized the technological level of possible extraterrestrials according to their energy consumption and their expansion in space. This is called the Kardachev scale. It has 3 levels: type 1 civilization consumes the equivalent of the energy produced by its planet, one of type 2 all the energy produced by its star and one of type 3 by all the stars of its galaxy .
Also, don't start dreaming of aliens. To tell the truth, Greg Hellbourg himself does not really believe that the Nançay radio telescope will find anything.
"The search for an unknown signal is extremely complex, and despite the excellent technical capabilities of the radio telescope, we will only explore a tiny part of the parameter space that can be explored."
- Greg Hellbourg
And that's why he judges this important experience.
An old quest ...
It is actually part of a larger program, launched in 2015 by a Russian billionaire and the famous physicist Stephen Hawking: Breakthrough Listen. The idea: unlock a budget of $ 100 million over 10 years to allow Seti researchers to conduct this experiment.
For the time being, researchers at the University of Berkeley, partly funded by this program, mainly used two telescopes. If Nançay's test is successful, the Breakthrough Listen could free up more funds to scan many, many more stars.
The search for extraterrestrials dates from long before this project. Seti was founded in the 1960s, at the start of the space age. Since then, he has been trying, in a way, to respond to the Fermi paradox: given the size and age of the universe, it is highly unlikely that we are the only intelligent species on so many billions of worlds. But then where are they all?
As you know, the Seti has not found anything yet. And since the late 1990s, funding has become scarce.
In fact, the Nançay radio telescope was used in the 1980s to search for extraterrestrial signals by the University of Berkeley, a pioneer in the field. In 1991, Jill Tarter (who co-founded the Seti and who is interpreted by Jodie Foster in the film "Contact") published a study explaining that the various French observations had given nothing.
So why start again? "Technology has evolved a lot, as has computer processing of data," says Greg Hellbourg. We can now observe more stars and radio waves on many more frequencies, all analyzed using very efficient algorithms to process heaps of data.
A drop in the ocean
However, the chances of finding a signal are objectively extremely low, for several reasons. The main thing is that we only observe a tiny part of the sky. At a well-defined point in time, during which a hypothetical civilization would emit a signal.
There are also other problems. For this test at the Nançay observatory, the radio telescope will scan on very specific frequencies. "We don't know of any natural astronomical source that emits such a fine", explains Greg Hellbourg. So logically, if a civilization wanted to signal its presence, it would surely use a frequency which cannot be parasitized by the celestial objects which populate the universe.
But the choice is still far too important. "We have therefore chosen frequencies which refer to molecules linked to life, involving for example carbon or oxygen", specifies the Berkeley researcher. Again, the idea is to say that if an extraterrestrial civilization wants to make itself known, it will put the odds on its side.
Straw and beam
The researchers then demonstrated a form of assumed anthropomorphism. Nothing tells us that life is necessarily made of carbon. That she necessarily needs oxygen. Let it communicate with radio waves. That she simply wants to communicate.
But this ocean is so gigantic and the glass at our disposal so tiny that we have to start somewhere. Besides, Greg Hellbourg does not think that the solution will come from the frequencies currently studied. "I think the signal that we will eventually find will be a broadband signal, because there will be information in it."
So why haven't we found aliens yet? Perhaps the chances of us being alone in the observable universe are actually quite high, as two researchers recently claimed. Perhaps there is another explanation, like those mentioned in the video above.
Perhaps we just haven't looked around enough stars. And perhaps we did not search with the right tools, with the right look. "The pulsars have always been there, we have always captured them with our telescopes. It is a somewhat strange processing of the data already recorded which allowed us to detect one for the first time. Now that we know this method , we've discovered thousands of pulsars. I think it will be the same with the aliens, "Greg Hellbourg hopes.
F I N .
