Are We Being Watched? Tens of Other Worlds Could Spot the Earth (eurekalert.org) 94
A group of scientists from Queen's University Belfast and the Max Planck Institute for Solar System Research in Germany have turned exoplanet-hunting on its head, in a study that instead looks at how an alien observer might be able to detect Earth using our own methods. From a report: They find that at least nine exoplanets are ideally placed to observe transits of Earth, in a new work published in the journal Monthly Notices of the Royal Astronomical Society. Thanks to facilities and missions such as SuperWASP and Kepler, we have now discovered thousands of planets orbiting stars other than our Sun, worlds known as 'exoplanets.' The vast majority of these are found when the planets cross in front of their host stars in what are known as 'transits,' which allow astronomers to see light from the host star dim slightly at regular intervals every time the planet passes between us and the distant star. In the new study, the authors reverse this concept and ask, "How would an alien observer see the Solar System?" They identified parts of the distant sky from where various planets in our Solar System could be seen to pass in front of the Sun - so-called 'transit zones' -- concluding that the terrestrial planets (Mercury, Venus, Earth, and Mars) are actually much more likely to be spotted than the more distant 'Jovian' planets (Jupiter, Saturn, Uranus, and Neptune), despite their much larger size. To look for worlds where civilisations would have the best chance of spotting our Solar System, the astronomers looked for parts of the sky from which more than one planet could be seen crossing the face of the Sun. They found that three planets at most could be observed from anywhere outside of the Solar System, and that not all combinations of three planets are possible.
No... (Score:5, Insightful)
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By the time the light from the alien planet has reached our Earth to let us determine it's habitable, the light from our earth has reached them.
Re: No... (Score:5, Funny)
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...what?
GP's point is that the light reaching them now doesn't allow them to see us as we are now, but as were x years ago where x is also the distance in light-years to the planet..
Re:No... (Score:4, Informative)
TFA does not mention which exoplanets, but they will need to be relatively close to detect our transits. By "relatively close" we would be talking 10-20 light years - so us, not our ancestors (apart from the kids here).
Anyway they would not need to look for transits when we are blasting radar beams and TV broadcasts in all directions, the latter of which which might be shit but nevertheless has strong self-correlation, such as we ourselves look for in the SETI project.
Re:No... (Score:5, Informative)
Anyway they would not need to look for transits when we are blasting radar beams and TV broadcasts in all directions, the latter of which which might be shit but nevertheless has strong self-correlation, such as we ourselves look for in the SETI project.
With the distance and dispersion they'd still have to have an helluva big antenna pointing in our direction. So much so that AFAIK we're assuming they have better technology than we have, we couldn't pick up a TV broadcast from an alien world. If we point a radio telescope at them and "ping" them they'd get the message with current technology - assuming the antenna is pointing in the right direction, but that's quite different from an accidental pick-up of a signal intended for Earth.
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With the distance and dispersion they'd still have to have an helluva big antenna pointing in our direction .... we couldn't pick up a TV broadcast from an alien world. If we point a radio telescope at them and "ping" them they'd get the message with current technology - assuming the antenna is pointing in the right direction, but that's quite different from an accidental pick-up of a signal intended for Earth.
You should tell the SETI project to stop wasting their time then.
Re:No... (Score:5, Interesting)
The first thing that will make Earth interesting is our Goldilocks position around our sun.
The second thing that will make Earth interesting is our atmosphere. We have an "interesting" atmosphere.
Both of those bits of information have been out there for a long time - longer than we've existed.
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>The second thing that will make Earth interesting is our atmosphere. We have an "interesting" atmosphere.
Say the carbon-based life form that likes oxygen.
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"No, but our ancestors might be."
1. They are watching 'I love Lucy right now
2. I find 'ancestor' offensive, you young whippersnapper
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No, but our ancestors might be.
You're not wrong. Based on the paper the closest planet we know of capable of observing the earth is 470ly away.
HATS-11 b = 2954ly
1RXS 1609 b = 470ly
LKCA 15 b = 470ly
WASP-47 b,c,d,e = 652ly
WD 1145+017 b = 520ly
Completely looking in the wrong place (Score:2, Funny)
The majority of life has two suns not one.
Our solar system is the anomaly.
The fallacy is thinking that our system is the standard. It isn't -- it is the exception -- we need to stop pretending the human perspective is the only one that matters, or is even right.
--
Atheist, noun, a blind man arguing with the rest of the world that color doesn't exist.
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I'd prefer Elly May myself.
Re: Completely looking in the wrong place (Score:3)
The majority of life has two suns not one.
Probably but it's not impossible that, for whatever reason, life might have a better chance of arising in a single-star system.
Don't phrase assumptions as facts.
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Probably but it's not impossible that, for whatever reason, life might have a better chance of arising in a single-star system.
Life is highly unlikely to arise on a planet around a double star unless the two stars were very close together. The temperature variations as the planet orbited them would be tremendous, that is if the orbit were stable at all.
Re:Completely looking in the wrong place (Score:4, Insightful)
The majority of life has two suns not one.
The majority of stars are in binary systems, but this does not necessarily mean that the majority of life will be found in such systems.
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No, but that's the way you'd bet.
Contact (Score:3)
Is it because they do not support life?
That their live is not advanced enough?
That they are trying to contact us, but we cannot detect their message.
That it is a quality of advanced civilisations that they ignore each other (or defer contact until some defined "level" of civilisation has been reached).
or are they on their way, right now.
Re:Contact (Score:4, Interesting)
Re:Contact (Score:5, Funny)
How often do they try to contact you?
Every day.
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I try to contact the ants in my back yard once a month through a visit from Clark pest control services
A Klingon pest control officer is on his way here now.
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How often do you try to contact the ants that live in your neighbor's back yard?
I never even try to contact the fucking neighbour, let alone his ants.
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If there were a new species of ants in your neighbors back yard, I am sure that you and a lot more people would be contacting them. Humans would be a new species to any advanced alien race so I also sure they would want to examine us. I am also sure that if anyone could find a way to communicate with any ants, a lot of people would doing so because I am sure the ants could teach us humans a thing or two.
Re: Contact (Score:4, Funny)
So why haven't these other worlds contacted us?
Turn on your TV: Would you want to contact any of those motherfuckers?!
Re:Contact (Score:5, Insightful)
Because the computers have taken over, and they're waiting for our computers. They don't want to talk to the meat.
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So why haven't these other worlds contacted us?
Give them a chance. Maybe 40 years ago they received our first strong radio broadcasts signals from 80 years ago, and their replies should get here real soon now. Bear in mind the first thing they heard might have been one of Hitler's speeches.
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Who says they haven't? The closest of them listed was over 400 light years away, so obviously they wouldn't have responded to any signals from us yet if we'd sent any strong enough which we haven't. They might well have sent numerous signals to us for millions or even billions of years and never gotten a response, finally giving up.
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Or we may be the most advanced civilization in our galactic neighborhood, and we are closer to being able to detect them than the other way around.
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So why haven't these other worlds contacted us?
Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us.
(with apologies to Bill Watterson)
What are the chances - probability? (Score:2)
My guess 100 % by the number of suns/exoplanets.
Yet, the time factor plays a big role - billions of suns ? light years apart, mutual observations are delayed, are they still valid? Alpha Centauri for sure, any other's?
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Time is indeed an important factor. For one, the universe is only 13 billion years old; a baby by cosmological time scales. Earth could be the first, or one of the first, worlds where life has arisen. We might actually be all alone for now.
Or if the universe is a simulation, then Earth might be the only place that either exists or has life coded into the sim.
Time Frame (Score:1)
We have come from building Stonehenge to identifying exoplanets in an eye blink of time in the history of the universe. To speculate on aliens using the same techniques that we have come up with in our current lifetime is kind of silly. Either they aren't looking for exoplanets at all, or they've developed much more accurate measures to detect other worlds than solar transits. (Or perhaps "they" don't exist at all.)
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One day, in the not too distant future, physicists will wake up from their self-imposed stupor and realize that distance is an illusion of the mind. It does not exist. We will develop technologies that will allow us to travel instantly from anywhere to anywhere. Of course, the aliens, if they exist, have figured this out eons ago and regularly visit us without our knowledge. :-)
Lead the way.
Guessing at alien technology is difficult (Score:5, Informative)
They are looking for worlds that could see us using our current technology. Its an interesting study, but 100 years ago we would have tried (and failed) with a very different technique (direct telescopic examination). 100 years from now we may be using a completely different technology (solar system sized interferometers?, Some new trick to drastically reduce stray light in an image? X-ray telescopes? I have no idea) )
We know nothing about alien technology (if it even exists). It may have followed similar paths to ours, but it might be wildly different.
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They're On Their Way (Score:2)
Re:They're On Their Way (Score:4, Insightful)
John Mulaney [youtube.com] has an outstanding story about "What's New Pussycat" and the best dinner he's ever had.
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I certainly hope you wrote that tongue in cheek.
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I think his tongue has done busted through his cheek by now.
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"First of all, the latter is in a foreign language and therefore won't be immediately connected with Earth."
I certainly hope you wrote that tongue in cheek.
English was spoken by the aliens in all the sci-fi films I have ever seen.
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Sure. "Universal Translators" can change anything to English, dontchaknow. Except Klingon.
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Yah, that's a great bit. I listen to it occasionally. He's a good story-teller.
"Watch the skies everywhere. (Score:2)
How Many Planets Are There? (Score:5, Informative)
Considering that we detect planets that transit the parent star, and that we've detected thousands of them, AND that such an occultation is visible ONLY when the Earth is precisely on the plane of that system's ecliptic ... the only viable conclusion must be that planets around other star systems are LITERALLY as "common as dirt". It's likely that there are planets around MOST stars.
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Considering that we detect planets that transit the parent star
Not so. Exoplanets can also be detected by slight wobbling of the star they orbit.
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According to a quick google, the current guess is 1.6 planets per star system in the Milky Way, for a total of 160,000,000,000 planets in the galaxy. And at least 1/6th of star systems are thought to have a terrestrial planet sized similar to Earth.
Meanwhile, on Sirius VI. . . (Score:3)
. . .we're reality Three-V.
". . . as J'mm tests the native female with the Anal Probe, consider how Mutual of Andromeda protects your homeworld from pesky alien intrusions. . . "
- Mrrl'nn Prk'nz, host of "Mutual of Andromeda's 'Wild Planet'"
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There are (at least) two other conclusions from the same data:
1) Those monuments were far easier to build than you think; and
2) There have been previous civilizations on Earth that rose above sticks and stones (although the evidence is against them having made it as far as we did - so far).
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The number of ray guns and nuclear reactors found in the ruins of ancient cities is truly proof that aliens were providing the technology.
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The number of ray guns and nuclear reactors found in the ruins of ancient cities is truly proof that aliens were providing the technology.
Maybe they made compostable weapons to keep the galaxy from being cluttered up with detritus from their endless wars. They used a lot of iridium in 'em.
Next on Sick Sad World (Score:2)
Look at those crazy fucking primates (Score:2)
We had better keep an eye on them and make sure they don't know we are here until they evolve.