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Breakthrough Listen finds no signs of alien transmissions from 60 million stars

Where are those alien civilizations? Breakthrough Listen, a privately funded project searching for evidence of alien life, has released the first results from its survey of 60 million stars in an area looking towards the galactic center, noting that it found no evidence of any technological transmissions signaling an alien civilization from any of those stars.

The paper can be downloaded here [pdf].

The kind of signals they were looking for were not beacons sent out intentionally by alien civilizations, such as television or radio broadcasts, but unintentional transmissions, such as radar transmissions meant for other purposes but still beamed into space. They found none.

Pioneer cover

From the press release: From the moment he is handed a possibility of making the first alien contact, Saunders Maxwell decides he will do it, even if doing so takes him through hell and back.

Unfortunately, that is exactly where that journey takes him.

The vision that Zimmerman paints of vibrant human colonies on the Moon, Mars, the asteroids, and beyond, indomitably fighting the harsh lifeless environment of space to build new societies, captures perfectly the emerging space race we see today.

He also captures in Pioneer the heart of the human spirit, willing to push forward no matter the odds, no matter the cost. It is that spirit that will make the exploration of the heavens possible, forever, into the never-ending future.

Available everywhere for $3.99 (before discount) at amazon, Barnes & Noble, all ebook vendors, or direct from the ebook publisher, ebookit. And if you buy it from ebookit you don't support the big tech companies and I get a bigger cut much sooner.


  • Lee Stevenson

    This is pretty depressing news …. All thru the 90s and 00s I was expecting some sort of signal ( I can’t have been the only one running “SETI @home”!)… But my hope is that pointing towards the galactic center was a mistake… Too much action going on… Point at the outer reaches of our spiral arms, like where we live… Solar activity is older and gentler and perhaps more conducive to the evolution of, “ahhhm”, civilization like us.

  • Richard M

    Honestly, it’s a bit of a relief to me.

    I think we should be a bit anxious about having any interstellar neighbors *too* close to us.

  • Andi

    Given that the signal strength would drop off with the square of the distance, could we really expect to detect any releases of energy into space given that those signals would not have been beamed at us?

  • brightdark

    How old is the galaxy compared to how old life is on Earth? Perhaps why we haven’t found anything is because they are already gone. The were born, lived, and for whatever reason, died out.

  • J Fincannon

    Andi: Precisely.

    Humans on the Earth broadcast high power one directional radar beams which have a much higher chance of being detected by other civilizations than our omnidirectional radio/TV broadcasts due to the reason you stated. Still, even using inadvertent radar, it is highly unlikely such civilizations could detect it. The reason is that the Earth is rotating about its axis and revolving about its star. A distant civilization would be in the same situation. For a one directional beam minimally spread beam, it would change its likely seen angular zone in the sky a lot. The alien planet receiver is in the same problem. Maybe they would see it once, but not twice.

    More likely the phase civilizations go through with radio, TV and radar is short, then they move on to quantum communications or something we don’t know about yet. Also, what use is getting a message from >100 years ago?

  • John

    I think they were actually looking for beacons. Haven’t read the entire paper but-

    From the intro 1.1: “In this paper, we will focus on strong beacons deliberately transmitted by ETI.”

    From the discussion: “We carried out searches for two different types of beacons which are likely to originate from (a) a transmitter placed near the GC illuminating the entire Galaxy and/or (b) any star in the lines-of-sight of our pointings towards the GC.”

    My own opinion is there’s little chance to find beacons. If we think about beacons from a transmitter’s perspective it takes a ton of 1) energy and 2) time. I know it’s not impossible to try and illuminate the galaxy, but that’s an incredible amount of power that would have to be maintained for an incredible amount of time.

    I think it’s far more likely for there to be listeners like us. But if you’re listening for unintentional signal leakage, it’s likely weak and probably only detectable for nearby stars.

    So, if you find something nearby and interesting, do you transmit a high-powered signal towards it for a few thousand years?

  • David Parsons

    When I was a child I looked at the stars and “knew” we couldn’t be alone. Then I grew up.

    We’re a big deal in this universe, and we’re alone here, but this universe is an insignificant thing among all of God’s creations.

  • Looking for beacons?

    I’m going to surmise that any civilization that has star-faring aspirations is going to be the apex life form/civilization/organization on the planet. That’s generally how the Universe works.

    If you’ve made your way to the top, ‘red in tooth and claw’; why in the heck would you advertise to potential threats?

  • Michael P

    Andi: Big dish telescopes are pretty powerful, although we could only hope to make out signals in frequency bands where stars are quiet. There’s a sign at the Green Bank Observatory in West Virginia (one of the two telescopes they used) that stresses how important it is to leave electronics far away from their radio telescopes; it says they would be able to detect your cell phone from Saturn — in airplane mode.

    Yes, as you allude to, stars are much farther away, and the paper gives bounds on what they could observe. The paper says an EIRP of 4e18 W for the large set of stars, and 5e17 W for a half million stars. For rough scale, our sun emits about 3.9e26 W of power, and the whole world uses about 2.7e12 W of electricity.

    You can boost EIRP a lot by using a parabolic dish antenna — a 25 m dish can get you a bit more than 50 dBi (100,000 times) and our largest antennas get almost 80 dBi (90 million times). So if somebody directed our entire current electricity consumption into a transmitter, and managed to pump that through the biggest antennas on Earth (the ones we actually have could not handle that much power), this study would have detected the signal… barely, in the smaller set of stars, and if the antenna was pointed VERY close to our direction.

  • Rick Caird

    Since we seem to have vast evidence of unidentifiable aircraft in our skies, why not listen for transmissions to and from the aircraft.

  • Holly

    With the estimated number of stars in our galaxy ranging from 100 – 400 billion, a 60 million sample is a drop in the bucket.

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