POLL: When Will Humanity Truly Find an Alien Earth?

[doublehelix]

On Thursday, Aug. 26, 2010, NASA announced the discovery of a planetary system that has been confirmed to have at least two Saturn-sized planets and – just possibly – the smallest alien planet yet seen – a candidate world that would be about 1.5 times the radius of our own Earth.

It is the second possible Earth-sized planet to be announced this week. What do you think? Cast your vote on whether true Earth-like planets the size of our world or smaller will be found around alien stars in orbits that allow them to be habitable.

More resources:

Newfound Alien Planets May Include Smallest One Yet

Alien Solar System Looks Strikingly Like Ours

Photo Gallery - Strangest Alien Planets

Top 10 Extreme Planet Facts

 

[3488]

Fantastic poll DH.

This is worth pinning IMO.

I voted for #3.

An Earth SIZED & MASSED planet could be like Venus, extremely hot, crushing atmosphere, or even 'airless' like Mercury or the Moon or nearly so like Mars if in the 'wrong' place. Or perhaps covered in frozen atmosphere like Neptune moon Triton or KBOs 134340 Pluto or 136199 Eris if too far from it's parent Sun.

Or major geological upheavals like Jupiter moon Io, if in proximity to gas giants as well as being in firing line of comets & asteroids if in a gravity well of a said gas giant, see Jupiter moon Callisto or Saturn moons Rhea, Tethys & Mimas or Uranus moon Umbriel.

Earthlike & Earth sized are two very different things.

Andrew Brown.

 

[SteveCNC]

When I look at what was discovered in the previous 10 years as compared to just the last year I can't help but think it won't be too much longer (maybe within 2-5 years) . Refinements in computer software used to scan images combined from multiple inputs from different types of sensors it can't help but happen someday . Of course our luck it will be a system over 1000 light years away but it's a start . Personally I'm hoping we find a brown dwarf within 1-3 light years , with a planetary system we can actually send a probe to , but that's my personal dream for extrasolar activities in the near future .

 

[ZenGalacticore]

I voted for #1. And I think it should go without saying that Earth-size and Earth-type are not the same thing. Although, the emphasis of the difference is probably needed.

In the next few years, if we find several different candidates, won't we be able to tell if they have atmospheres like Venus or Earth? Cannot free oxygen be remotely and spectroscopically confirmed? Water vapor? Aren't we working on these techniques as we speak?

I know I read a few years ago that planetary scientists were studying the reflection of earthshine from the Moon, and they were saying that through the absorbtion lines, that they could tell Earth had a nitrogen/oxygen atmosphere. Granted, the Moon is very close, but it holds promise for the future of remote identification of alien atmospheres.

If we are able to study hundreds of thousands stars and actually identify 1,000s or 10s of thousands of alien systems, then it's only a matter of time before we find scores of Earth-type candidates. The discovery may come sooner than we think. But, since we still can't easily detect bodies the size of Earth and Venus, I'd wager that Earth mass planets are very common, and Earth-type worlds are probably more numerous than most people suspect.

 

[doublehelix]

Fantastic poll DH.

This is worth pinning IMO.

I voted for #3.

Thank you, Andrew, but your thanks should be directed to Tariq Malik, who wrote the poll!

I'll consider the pinning, too.

-dh

 

[jerrycobbs]

I do think it's only a matter of time, and not necessarily a long time, before we find Earthlike and not just Earth-sized planets. However, I also think it may turn out that the most likely places for life may be large moons around gas giants. I would not be at all surprised to find that stand-alone life bearing planets are more the exception than the rule. In that case, I'm not sure how difficult it will be to detect those moons as opposed to finding solitary Earth-type planets.

 

[FITorion]

I think it's a cross between the bottom two. It's only a matter of a few years until they put an interferometer up there that can get spectra-graphic data on the atmospheres of Earth sized planets. It would also be able to see planets that don't cross between us and their star.

So it's a major advancement but it's not very far off. I expect we'll discover a true Earth like world in the next 10-15 years.

 

[3488]

Hi jerrycobbs,

Excellent reasoning. Something that member Silylene correctly pointed out on another thread regarding Earthlike moons in orbit around gas giants such as scifi worlds Endor as depicted in Star Wars or Pandora as in Avatar, is that whilst these worlds like these may physically exist & there is no real reason why not, is that because they are deeply imbedded within the parent gas giants planetary gravity well, impacts from passing comets & asteroids will be frequent & devastating.

Jupiter for instance has been struck twice during this Summer alone, in June & August. Look at Callisto, the outer most of the Galileans. Absolutely pockmarked. Ganymede too is not short of impact craters, though Ganymede has erased many due to tectonics & cryovolcanism, Europa too is not entirely crater free, though Europa appears to have resurfaced itself approx 30 million years ago & Io is just so volcanically active that impact craters do not last long (there are two candidates, a small ding in Heno Patera volcano & a small ding in Zal Montes, though these could be magma withdrawal sag pits).

Also Saturn, Uranus & Neptune have deep gravity wells, some of their moons are also very heavily pockmarked, largely due to the concentration of impacting bodies owing to the gas giants gravity wells.

Andrew Brown.

 

[RayW46]

Your poll results are surprisingly even. This shows a widespread difference of opinion among your subscribers. The meaning of "earth-like planet"is up to individual interpretation. In voting for #1, I take the term in a broad sense to mean any rock-like world capable of supporting life. I think, from what we have already discovered among exoplanets, there must surely be many earth-like planets and we are close to finding one or more around our neighborhood.

 

[PA_Newbie]

My vote would change depending on the intended meaning of "truly find" is in the poll. If finding an "Alien Earth" simply means finding a rocky planet in orbit in the habitable zone of a star, I have no doubt this will happen within the next year or two, and that there will be several "candidate" Alien Earths discovered.

If you are going to require proof that life actually exists on the planet as part of "truly finding" an Alien Earth, this will not happen for a long time unless an advanced Alien Civilization contacts us or we pick up signals from them. Besides these methods, there is no current technology that I'm aware of that could detect signs of non-intelligent life around another star, and I suspect this will not exist for quite some time.

Personally, I'd settle for a combination of the two - to me, if someone were able to show that a rocky planet existed in the habitable zone of a star, and also show that such a planet had a Nitrogen/CO2/Oxygen atmosphere, I would be satisfied and consider it an "Alien Earth". I can see this coming within a couple decades - while we won't be able to see or prove life actually exists, we could, in that timeframe, be able to see signs that a planet would be hospitable to life as we know it.

 

[m2horton]

I voted for #1.

I do believe that we are truly close discovering an earth like planet. Once again adding to the discussion as everyone else did were talking about an earth like planet not an earth sized planet. With the latest discoveries by Kepler there is no reason to think otherwise. We are finding hundreds and hundreds of exoplanets that are Jupiter and Saturn sized planets. Orbiting stars that we thought would never have anything orbiting them. And the more we discover the more we are learning about these alien like solar systems surrounding us. I believe a total of about 15 different solar systems have been discovered and are in stages to confirm these findings.

I think Kepler is the greatest instruments ever created. And things are only going to look up from here. Another thing we dont realize is that Kepler was launched close to if not less an 1 year ago. And look what we have found thus far. Given our technology and the rate in which is grows I believe that we will discover an earth like planet within the next 6 years. With many other discoveries along the way.

I know many will disagree with my answer and that's ok. Many others dont realize that if we do happen to find an earth like planet that we do confirm to have an abundance of rich oxygen and vast oceans of water that does harbor life, the general public will be by far the last to know about it. Confirming life on other planets will only conflict with life here on earth. Leading many to lose faith in what they believe in and questioning there exsistance in this universe. And we cant have the millions of people who "believe" lose faith right? Even though we most dont realize ... coming from a science perspective ... there is no religion. Just guidelines individuals have made up to keep peace in the world.....

 

[elroy_jetson]

I think we're close to finding Earth sized, but it will take a few years to find an Earth-like planet. Our rock is pretty special, a rare gem, if you will. The one Earth sized world we do know about, Venus, isn't all that Earth-like. Perhaps one day we'll terra-form Venus into a true Earth twin, but that time is in the distant future.

 

[ZacFarr]

I voted for number 3.

I think that an "Alien Earth" is not going to be found in the near future(10-15 years), but I do think that technology will improve to the point where the criteria for a "Habitable" planet will become less specific to what is found on our planet. More heat resistant materials and improved oxygen recycling systems are being designed constantly, so while an "Alien Earth might not be found soon, a "Habitable" one might be found very quickly.

 

[lovespace123]

Why are you asking us this questions? Scientists have already identified and of course contacted aliens

 

[MeteorWayne]

No, scientists haven't. Loony Tunes, woo-woos , and non-scientists have. :roll:

 

[MENOC]

Well,

Voted #2

I think earth-like will be difficult to find, but an approximation stands a good chance. Titan might be considered an approximation and so is Mars but a true earth-like exo-planet ( with the same type of oxygen rich atmosphere, Oceans that are stable, Plant life that use photosynthesis as well as carbon base life, and most importantly, with about the same force of gravity acting upon everything within it) will be difficult to find. As I said before, we have already found close approximations in Titan, Mars and maybe even Venus. All these systems pretty much all share the same elements so we will find one that will match earth-like conditions but we will have to do a lot of stellar digging before we find it.

 

[reinux]

What exactly do you mean by "alien earth" anyway?

Something with vegetation? Microbial life?

 

[General_Kenobi]

#3 for me. But that's just becasue I define "Earth-like" as habitable, as Earth is by humans. Really, though, "Earth-like" needs to be more clearly defined. Every astro publication I read uses the term as a broad comparison in size.

 

[Sycamorefan]

I tend to agree with with those on here that believe finding another rocky, terrestial planet in a nearly circular orbit in the " Goldilocks Zone " around another yellow star with a .65g-1.1g gravity well and a 22-24 degree tilt to its axis that it rotates on and has several gas giant planets shielding it from bombardment and has a moon (or moons) with enough mass to create gravitational tidal forces strong enough to maintain plate tectonics, but not strong enough to create a volcanic hell, oh and lets not forget about planetary core of the right composition & mass to create a strong magnetic field so that the star's solar wind doesn't strip away that nice breathable atmosphere, is not going to be a dime a dozen ( sorry Trekkie fans).
Don't get me wrong, I do believe that there IS another Earth-like planet out there somewhere. With 400 Billion chances of similiar occurance just in this galaxy alone, I'd take those odds to Vegas any day of the week!
What I am saying is this, Kepler can detect planetary bodies as small as 1/5 the size of earth, Why aren't they searching ALL the planetery systems with Gas Giants & Brown Dwarves out there ( not just ons with yellow stars ) that are within the Goldilocks zone (and maybe slightly beyond) that have other Gas giants or BD's further out, that has .25 or less eccentric variable to it's orbit and is 150 light years away or less. I have a gut feeling that they will find an Exomoon around one of these 4x or bigger than Jupiter Gas Giants or Brown dwarves that will be enough like earth to be passable habitable. I fear looking for an exact copy of earth, in an area 10,000 light years away, will not yeild the kind of results needed to fuel the Public's imagination or convince the politicians to increase NASA's budget.

 

[pgwater]

I just can't wait for the moment like in Pandorum or Battlestar Galactica when a moon comes into view and then what appears to be a second Earth. But I will settle for another "pale blue dot".

 

[adrenalynn]

Sycamore - great post!

I would add, though, that most seem to look at this three dimensionally. I think that's a pretty big mistake, statistically. We need to consider 't' here.

"That was an outstanding planet. You'd have wanted to build a summer home there. Really pretty. 1.725 billion years ago, before the [insert cataclysm here]." Or on the flip side: "It will be an outstanding planet, after [insert cataclysm here]"

Killer asteroids, solar life cycle, ginormous comets, ring-of-fire events, moon-loss, drift, pole reversal, [...]

Our own planet is just one bad card away from extinction. If you want an "Alien Earth" then you need to assume that that planet is subject to the same things. Given enough time (and enough monkeys with typewriters, I'm sure), you'll find another rock that might have been, or could some day be. But the total time we've been looking versus the life of the known universe suggests that it's not going to happen today. It's not just the physical that needs to line up, it's the time window in which we observe it. Otherwise, there's an outstanding chance that Mars already qualifies, and quite probably our twin, Venus...

 

[Yuri_Armstrong]

They've already found a pretty good candidate: http://en.wikipedia.org/wiki/Gliese_581_d

As sycamore said there's a lot of factors that go into making Earth the habitable planet it is for us today. I'm not sure if there's much point in looking for Earth-size planets, they could be just as uninhabitable as Venus. Gravity probably doesn't have much effect on potential life, so long as the planet has enough gravity to maintain a good atmosphere.

Instead of finding more candidates we need to be focusing on studying potential ones. If we can learn more about Gliese 581 d's atmosphere, enviornment, and other properties we can get a better understanding of what that planet is like. If it turns out to be somewhat like Earth, then it's quite likely it will hold life. Conditions here are perfect for an abundance of millions of species of animals. As for actually getting pictures of the planet, I'm not so sure. The light from its star would probably block out the light from the planet. I'm sure that one day though they will be able to take high resolution photos of these alien planets, we just need to keep improving the technology.

 

[StarRider1701]

I voted #1. We are nearly there as far as finding Earth sized planets around other stars. Finding Earth sized planets in the correct orbital zone around a nearby star is going to be the best we can do to satisfy "Alien Earth." Not sure why anyone considers Venus habitable unelss one likes living in Hell. The same can be said for Mars, Hellish cold. We should be able to tell given the amount of radiation from a given star whether or not an earth sized ball is in the right orbit to be a Venus or Earth or Mars. Or something in between. As another poster said, we don't really have the abiliity to be able to tell whether or not it is a life bearing world at this distance. But we are getting there, we've found a planet that is only 1.5 times the size of Earth so we're almost there. Can happen anytime.

And yes the planet does need to be Earth sized to be Earth like. Gravity plays an important role in our lives - too much or too little CAN make a difference. Especially too much. A little too little I think we can adjust to.

Not sure where anyone got the notion that planets like Earth are rare? Since we've only started being able to see planets around other stars for the last decade or so, what is that notion based upon? Especially since some of the planets we found did not conform to our ideas about planets and other solar systems. I think we will find that living planets like Earth will be as common as dirt out there.

I think the next few decades will be quite exciting with regards to what we will find out there in our immediate neighborhood. My prediction is that planets that are the approximate size of Earth and inside the real habitable zone (no I don't include Venus or Mars as being within that zone) will be quite common. I know that we can look at any given star and calculate exactly where Earth would need to orbit to receive the same amount of light that our Sun gives us now. So the arguement over "Earth like" and "Earth size" is just silly semantics to me. At this point in our technology all we can see is if a planet is Earth sized and in the correct orbit. For us, for now that will have to define "Alien Earth."

 

[adrenalynn]

Not sure why anyone considers Venus habitable unelss one likes living in Hell. The same can be said for Mars, Hellish cold.

Because, for all indication, at one time Mars wasn't tectonically dead. And Venus hadn't yet choked to death. And there are a LOT of organisms right here on earth that DO enjoy hell very much. Living under a quidzillion tons of pressure sucking down the sulfur dioxide of Smokers, or in the darkest caverns feasting on acids that'd make a car battery blush.

Again, you're looking at today, and at instant gratification. We have to look no further than our own immediate neighborhood to see that time really is the limiting factor.

 

[kk434]

After reading parts of the book "Rare Earth" and analysing the exo planet data i voted for a "slam dunk" nr 3. Our solar system is the exeption not the rule. Hot Jupiters, 5 day orbits, chaotic binary star systems is the way of the universe.