What is the status of the search for extraterrestrial intelligence?

What is the status of the search for extraterrestrial intelligence?

The search for extraterrestrial intelligence elsewhere in the universe has leapt to prominence once again, with the announcement of the Breakthrough Listen initiative.

Announced this week and funded to the tune of US$100 million by Russian billionaire Yuri Milner, it will be a high-risk, high-reward program searching for signals from intelligent aliens – definitive proof that we are not alone.

The idea that we might not be alone in the universe is not a new one. It has passed in and out of vogue for at least the last few centuries with past astronomers speculating on advanced life on our neighbouring planets.

Could Mars have been home to a dying civilisation, transporting water from polar ice caps to the warmer regions near the planet's equator? Could a thriving biosphere have lurked beneath the clouds that cause Venus to shine so brightly in our night sky?

Astronomers eventually revealed planets that were far from the oases they might otherwise have been. Rather than a verdant tropical planet, Venus turned out to be a hellish, pressure-cooker world with a surface hot enough to melt lead. And Mars is a cold, arid, husk of a world, poorly suited to complex life.

So if we want to find life like us – someone alien to talk to – we have to cast our net more widely. And this is where the Search for Extraterrestrial Intelligence (SETI) comes into play.

The SETI initiative

The idea is that once a species becomes sufficiently technologically advanced, it will advertise its presence to the cosmos in some way that could be detected by astronomers on other worlds.

As a species, we have already passed that point. Some argue that our modification of our environment was the threshold. That agriculture, and the controlled use of fire, would have made us detectable by advanced alien astronomers thousands of years ago.

SETI, however, is more interested in the technological broadcast of life's existence. The radio and television broadcasts of the last century will provide definitive evidence of our existence to any alien observers, so long as they know where to look.

The first transatlantic radio broadcast, by Guglielmo Marconi, occurred in 1901. Of very low power, the radio waves emitted in that broadcast that escaped Earth will now have travelled for 114 years, out towards the stars that were above the horizon for the broadcaster.

Over the years, our broadcasts have became louder and spread across the electromagnetic spectrum. As a result, a vast and ever-expanding bubble of space centred on Earth is full of our noise. If they knew which frequencies to study, aliens at the right distance would be able to tune in to coverage of the 1936 Olympics, the coronation of Queen Elizabeth II or even watch episodes of Neighbours.

If we are broadcasting to the universe, then perhaps others are too? If so, SETI aims to uncover their signals – the evidence that there is not only life, but life like us, somewhere out in space.

That search has proceeded intermittently for years with different groups of scientists using ever more advanced tools to search for a needle in a haystack. The Breakthrough Listen initiative is simply the latest.

Early searches for life out there

Just as our early thoughts on life beyond Earth were focused at our own solar system, so was our search for alien life. An astonishing example was the National Radio Silence Day, held in the US during a particularly close approach between Earth and Mars in August 1924.

For a period of 36 hours around the time of closest approach, the US government asked civilians to maintain radio silence for the first five minutes of every hour.

During the periods of silence, radio receivers listened to the heavens, searching for signs of a signal from the Martians.

None arrived.

As technology continued to improve, so did our efforts to detect the signs of extraterrestrial technology. In 1960 the first true modern SETI program began with Project Ozma.

Led by renowned radio astronomer and astrobiologist Frank Drake – who created the Drake Equation which estimates the number of potential civilisations in our galaxy – Project Ozma used a large radio telescope to listen to two single nearby sun-like stars – Tau Ceti and Epsilon Eridani.

The observations continued for six hours a day for a period of several months. The astronomers involved concentrated their efforts on of wavelength 21 centimetres (1,420 MHz), an astronomical hailing frequency at which radiation floods the universe from cold hydrogen gas between the stars.

The 21 centimetre wavelength is one that has often been used as a target for SETI, the thinking being that it would be an obvious frequency for alien civilisations to chose for communication with newly fledged technologies.

Again, we heard nothing.

But still the searches continue. The odds of finding something are very low, but the potential reward so great that it is definitely worth trying.

Anyone can help in the search

Prior to the latest announcement, the SETI project that most captured the public imagination was SETI@home.

That project used the downtime of computers around the world to search for signals from beyond through a screensaver people could install on their home computers. At its peak, the project involved more than a million users, all participating in the search for life elsewhere.

And again, nothing has been heard.

Which brings us to our current headline maker, Breakthrough Listen, launched by eminent and world renowned astronomers, including Frank Drake – now chairman emeritus of the SETI Institute – and the theoretical physicist Stephen Hawking.

And Australia will play a key role through the Parkes Radio Telescope.

The new program dwarfs all previous searches. It will cover ten times the area on the sky, scan a swathe of the radio spectrum five times broader, and do all that one hundred times faster than any survey before.

The project will not only scan the million closest stars, it will also look for signals from throughout our galaxy. It will even look at the 100 closest galaxies, searching for extra-galactic signals.

The data taken by Breakthrough Listen will be open so anyone can access it. It will be tied in with SETI@home meaning that anyone with a home computer will be able to help in the search through the data.

If we find incontrovertible evidence of intelligent life beyond Earth it would probably be the single most breathtaking discovery in history. Then, the real work would start.

Are they close enough to contact back? Could they already have heard us? That all plays into the second new Breakthrough Initiative project – Breakthrough Message. But that's a story for another day.


Explore further

The hunt for ET will boost Australian astronomy

This story is published courtesy of The Conversation (under Creative Commons-Attribution/No derivatives).The Conversation

Citation: What is the status of the search for extraterrestrial intelligence? (2015, July 22) retrieved 22 September 2019 from https://phys.org/news/2015-07-status-extraterrestrial-intelligence.html
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Jul 22, 2015
I therefore propose a scale for status on extraterrestrial intelligence (lower is more alert):

4. bupkis (default state)
3. optimistic (expert and/or older physicist is optimistic about the future of EI)
2. fake picture (on the internet)
1. false alarm (signal was actually coming from a microwave)


Jul 22, 2015
Strange comments, full of certitude and irrefutable truth. WE ARE ALONE. It sounds like an awesome movie title.

Or we're unskilled observers? A millenia ago, the Earth was flat. Few centuries ago, steel would never allow human to fly in the air. And probably many other things no decent human being would ever defy.
And here we are. I agree we found nothing yet. I agree we may not find anything tomorrow and the day, the year, the decade after. But who knows, maybe one day...?

There's something i trust way more than the so called solitude mankind have to face. Future is certainly not written in those comments. Only in facts. Let's wait for em.

Jul 22, 2015
It seems to me that the general population already know what et looks like. How good is that?

Here is my prognostication. We will find et. We will not recognize et. We will eat et. When (eventually) we recognize et's intelligence the enlightening will be too embarrassing and we will continue to eat et.(Especially the baby ones. They are just so delicious. )
We will be The Monsters from Outer Space.

There is much superior intelligence here on your own planet, Ape, that you refuse to acknowledge because you prefer to eat it.

There is a reason the other planets are so far away from you.

Jul 23, 2015
It would be useful to define intelligence first because humanity did not define it adequately yet. When we eventually learn what intelligence is we will be able to start to really look for it, but first among ourselves, humans.

I myself deride those staunch critics of the SETI calling it waste of money and failure. I thing SETI got it right. They just did not notice that they got their answer i.e. silence.

This silence is a proof that extraterrestrial higher intelligence exists, since they, exercising their superior judgment and knowledge, did not even bother to respond to some primitive utterances of thinking outcrop of useless creatures that are just a blip that will disappear soon with absolutely no consequence to the universe. And that's what aliens hope for. But they may be wrong.

Or may be objective reality of universe is different of what we think? May be aliens are us?

https://questforn...reality/

Jul 23, 2015
In a universe teaming with life, all we are likely to hear is the sound of crickets chirping:

1) The 1974 Arecibo transmission was expensive, covered a narrow range, and the nearest star is 4 LYs away. Savvy business thinking comes into play... what's the ROI (return on investment)?
2) Motivations? If civilizations are not found within an acceptable communication range... ROI. 20 years for an ROI? Advanced civilizations are business-savvy civilizations.
3) ROI... Mining? Commerce? It does need to be thought through... here's a good explanation of the physics that kills this dream stone cold:
Looks like I'll have to post link separately... this site is NOT user friendly :(
4) There is only one thing that might work... a yet undiscovered communication technology. The technology proposed in this ambitious project is using a horse-and-buggy to cross an ocean.

There is no Fermi paradox. Everything is as it should be, in a universe teaming with life.

Jul 23, 2015
... continued from previous post:
3) The question of ROI... Mining? Commerce? It does need to be thought through... here's a good explanation of the physics that kills this dream stone cold:
damned thing still doesn't pass the smap filter... google the following for the excellent New Statesman article that I want to link to:
near-light-speed-travel-increasingly-impossible-according-maths

Jul 23, 2015
IMHO (Stumpy shield raised)

Looking for EM signals from ET won't work. Too far away. Signals require unrealistic power and time.

If (or when) we understand, something like, the underlying process of 'quantum entanglement/teleport' or some similar FTL effect (that could allow FTL info comms) then we might find a signal. Perhaps a Higgs field signal demodulator.

Note to self: Must remember .. Take meds.

Let's hope they are not carnivores.

Jul 23, 2015
It seems to me that the general population already know what et looks like. How good is that?

Here is my prognostication. We will find et. We will not recognize et. We will eat et. When (eventually) we recognize et's intelligence the enlightening will be too embarrassing and we will continue to eat et.(Especially the baby ones. They are just so delicious. )
We will be The Monsters from Outer Space.

There is much superior intelligence here on your own planet, Ape, that you refuse to acknowledge because you prefer to eat it.

There is a reason the other planets are so far away from you.


Now that's ridiculous. If we find ET's outside of our planet, we'll recognize them because....well, they'll be outside.
Then we eat them? WTF? If you're hungry, go get yourself a pizza. Stop looking at ET's!
As for their intelligence, we'll obviously have waaaaay too much observations to do before even approaching them. Not for their sake, but for ours.

Jul 23, 2015
That'll prevent us from being embarrassed for sure. And from eating the baby ones. They'll be toxic. Fact....?
Final words? Anti-humanism is supreme hypocrisy. That's not defending "superior intelligence we're eating". Just blaming the top of the food chain. It can be changed, but not with negative members of mankind. Those can remove themselves from the world. Smarter "world changers" can save Mother Earth with less discuteable suggestion.
And damn, if there's a reason why the other planets are so far away from Earth, i doubt you got the right one!

Jul 25, 2015
Now that's ridiculous. If we find ET's outside of our planet, we'll recognize them because....well, they'll be outside.
Then we eat them? WTF? If you're hungry, go get yourself a pizza. Stop looking at ET's!
As for their intelligence, we'll obviously have waaaaay too much observations to do before even approaching them. Not for their sake, but for ours.


Humans, somewhere in the world, eat literally everything we encounter, including other humans.

Even if it was illegal, and even though killing a sentient being for food would be morally wrong, you can bet that some "poachers" would want to kill and eat the aliens, especially superstitious people like in some parts of africa and asia, where they think eating an animal (or a human) gives them some sort of spiritual power from the victim.

Examples might be Islamic african warlords who kidnap, brainwash, and rape little girls. Nothing's stopping them from doing that to humans, much less aliens.

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