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Could An ExtraTerrestrial Find Earth with a Telescope?
Active Seti writes "If aliens were hunting life outside their own planet, could they peer through the vastness of space and lock onto Earth as a likely home for life? Researchers say with a roughly Hubble-sized array observers could measure Earth's 24-hour rotation period, possibly leading to observations of oceans and the chance of life. 'They would only be able to see Earth as a single pixel, rather than resolving it to take a picture,' said Astronomer Eric Ford. 'But that could be enough for them to identify our planet as one that likely contains clouds and oceans of liquid water.' The research will be useful to astronomers designing the next generation of space telescopes on our planet, because it provides an outline of the capabilities required for studying the surfaces of Earth-like worlds."
We should totally arrange some stars into a smiley face or big arrow pointing at us then (yes I know that would only look right from certain angles, it's a joke). But you've got to wonder why some other super advanced civilization didn't move some stars around to circle themselves or something and make it really obvious where they lived.
Google's Super Secret Search Algorithm: SELECT @search_results FROM internet WHERE @search_results = 'good'
The article makes a lot of assumptions such as:
(1) Life on other planets has the same requirements for existence as us (Class M
planet, water, air like ours, gravity like ours, etc)
(2) Extra-terrestrials will be using technology similar to ours (as opposed to more advanced tech)
(3) (Basing off #1 being true as they did) there are planets suitable for life such as ours that
we haven't yet discovered that are looking in our direction.
StarTrekPhase2 - The Five Year Mission Continues!
Phoo, once you've detected O2 in the atmosphere, you're done. Only life could produce that much free oxidizer in a strongly reducing universe.
........that aliens see things the same way we do. What if they "hear" on the same spectrum that we "see"? We could what-if this to death, but it's important to remember that listening might be just as important as looking, and not just for SETI.
If we really want to explore the stars, we must focus on high-risk projects that bust the fundamental notions of science. One such project is the hyperdrive. Burkhardt Heim developed a unique (almost incomprehensible) field of physics. If he is right, then we can build a space ship to visit the space alien peering at us.
Note that one deduction from Heim's work is a formula for calculating the mass of fundamental particles. The formula has been subjected to review by esteemed physicists and is 100% accurate. Could the hyperdrive be another valid consequence of Heim's work? The possibilities are quite tantalizing.
"To boldly go where no one has gone before ..."
"Yet across the gulf of space, minds that are to our minds as ours are to those of the beasts that perish, intellects vast and cool and unsympathetic, regarded this earth with envious eyes, and slowly and surely drew their plans against us."
"Ain't no right way to do a wrong thing."
That ET will find us with a microscope.
Well, if extraterrestrials were able to see earth using electromagnetic radiation (ie light, radio waves, ect) depending on their distance they would not see a modern earth. If they were over 5 billion light years away then if they looked at this solar system the Sun and the Earth would just be forming. This is because light speed is too slow. By the time the light reaches the extraterrestrials a large amount of time would have passed. They would have to use something other than a telescope to see a modern life sustaining Earth.
Rings around a gas giant means "keep the hell away from this system and don't, whatever you do, let the inhabitants get out".
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Whoa - if their smiley were pentagon-shaped I'd definitely run! Other civilizations with pentagon-shaped things aren't famous for being friendly towards people who are "different".
open (SIG, "</dev/zero"); $sig = <SIG>; close SIG;
Exactly, which is why the occasional "SEE, NO OTHER EARTH LIKE PLANETS!!!" as proof for everything from "life is rare" to "ghod created us" are all silly noise.
Any sufficiently advanced technology is indistinguishable from a rigged demo.
I see your humor, but...
A single pixel can provide a hell of a lot of information: Do spectroscopy, and you can get the typical absorption lines (O2 for example should be easy to detect, and be a sure way for _anybody_ who detects it to tell something is odd about that planet).
Track the intensity over time, and you can get the rotation period.
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
We've already been discovered, twice.
The first time: they discussed us using irrelevant analogies, took a senseless poll, said things like "imagine a Beowulf cluster of these" and "itsatrap!", and one alien remarked "I, for one, welcome our new Earthling overlords."
The second time: they just shouted "DUPE!" and moved on.
-David
When I see Earth with Google Earth (by the way, FSF, where I am a member, has called the creation of a free compatible client a high-priority project, and if you have free time please try to help, and if you need hosting for your project I can give you), I hardly can detect life, let alone humans, on Earth. Visually it's very difficult to detect it (and nothing suggests that an alien would expect a green planet to be filled up with plants, in fact a scientist would expect plant life to be red-coloured and in fact that's how it was in the past as red-colour has greater absorption efficiency... Earth plants became green only after changes in the atmosphere). I can see, of course, that the planetary atmosphere is a very dynamic system (clouds go and come every day), but all the rest is nothing but white places over the poles (ice), vast blueness (oceans), a few greenie plains (jungles, where remained by the human effects), and some light brownish-yellowish regions (deserts). That's all. I would need to analyse the Earth's spectrum or possibly other means to find out what chemistry this funnily coloured vastness has.
But wait, there's more: I can zoom in a little and see mountains etc. And if I zoom more I see that some oceans have little green islands in them, so perhaps I could start to understand that this bluish abyss could be some kind of liquid and the greenish spots could be areas of higher elevation. But still, it could very well be a dead planet with no life, let alone humans. So I have to zoom more. Oh, now I can see that there are some grayish spots near the greenery, as if someone had vomited on the Earth's plains. Yea, it certainly looks like vomit, but what is it? Zooming more... oh, it looks different from anything else, it has some kind of structure, lines etc. Still looking like vomit, though... structured vomit. Who the hell vomited on the planet we, the alien scientists, discovered? How can we write a paper on a vomited planet? Everyone will laugh, our academic reputation is at risk because of this vomit on this extra-Gliese planet.
But let's move away from this freaking vomit and look closer at the green plains and the brownish-yellow regions to see what there is there to be seen. Zoom a bit... oh what's this? Some kind of lines in the desert? Oh, it looks like other aliens visited this dead planet earlier and played some earth games on it, eh? Perhaps they were having some kind of planetary football games or something and this was their soccer field... But wait, some lines are quite intriguing. Nah... these aren't lines, these are complete drawings. Let's move away a bit and zoom closer... Hm, here these look like symbols. Ok, there may once have been some intelligence on this planet, but now it must be dead, probably, as it is too far away from its star (we the aliens like hot stuff so we live near our star, and this is what we consider the only habitable zone possible, for us if it feels hot it's good and we believe the whole universe is somehow made for us to explore and play in, so any planet outside our habitable zone must be dead because that's what the big scientists here say).
Where did this intelligence come from? Maybe it came from the vomit, so let's go back there and zoom more. Wow, what's that? It looks like the lines that divide the vomit in little rectangles have little ant-like things running over them. Oh, and by these lines there are big boxes. But what these boxes contain? Maybe there's more vomit in there! Ok, our scientists found the truth, these running things transfer the vomit from box to box! And maybe this vomit is intelligent! But not much, as it probably has not discovered telecommuting or work-from-home yet. And that's what we would expect from a planet outside the habitable zone, it must be so cold these (15-25C, which for us is too cold) that this vomit has its intelligence sabotaged by the tem