POLL: When Will Humanity Truly Find an Alien Earth?

[Sycamorefan]

Some have stated on here that I'm some sort of an optimist! Your wrong, I'm a realist! The Earth will not last forever, and it's resources are very finite, even with recycling. If you combine that with up and coming technology like Room temperature superconductive materials, Gamma Radiation blocking plastics and Fusion Reactor powerplants, the demand for Rare Earth Elements will drive us out into space. In this case "Greed is good"! Our first stop will be the Moon, then Mars and then the Solar System's biggest booty chest of all! The Asteriod Belt between Mars and Jupiter!
Wall Street types have already estimated its value at 20 Trillion dollars per person (7 billion people). Base instincts like saving our own skins and pure greed will drive us into space, not something altrustic like knowledge or discovery.
If you need any proof of this, look no further than whats happened to the wreck of the Titanic!

 

[eburacum45]

Problems with habitable moons;
1/ Most moons are smaller than habitable size. Large moons big enough to hold an Earth-like atmosphere at Earth-like temperatures are probably rare.
2/ Gas giants tend to have a strong magnetic field which traps radioactive particles, making the environment near the planet dangerous to life.
3/ The moon would probably be tidally locked, so it would rotate quite slowly with respect to the local star- making the days much longer than on Earth. This would make the environment on the planet quite unlike that on our planet.
4/ They will be difficult to see next to the gas giant they orbit.

Apart from those little problems, the idea is sound.

 

[Sycamorefan]

Problems with habitable moons;
1/ Most moons are smaller than habitable size. Large moons big enough to hold an Earth-like atmosphere at Earth-like temperatures are probably rare.
2/ Gas giants tend to have a strong magnetic field which traps radioactive particles, making the environment near the planet dangerous to life.
3/ The moon would probably be tidally locked, so it would rotate quite slowly with respect to the local star- making the days much longer than on Earth. This would make the environment on the planet quite unlike that on our planet.
4/ They will be difficult to see next to the gas giant they orbit.

Apart from those little problems, the idea is sound.
eburacum45
comet

Sorry, there are some problems the with points on this post:
1. most of the Gas Giant planets/ Brown Dwarves found so far are much larger than Jupiter or Saturn, so it follows that some of their moons should be proportionally larger as well. Also, the gas giants in our system didn't migrate from the outer solar system into the habitable zone as seen in most of the solar systems found so far. As this occured, it wouldn't be beyond the realm of possibility that the innermost gas giant picked up a terrestrial planets as new moons!
2. Yes its true, Gas Giants do have large radiation belts around them. This won't be a problem for a Terrestrial moon for 2 reasons; 1- Any moon with a gravity well of .5g or better MUST have Iron and nickle at its core. 2- Gravitational forces of the host planet will heat up and swirl that iron and nickle core of the moon as it rotates the planet. The byproduct
of this is a very strong magnetic field, much stronger than earth's and more than enough to generate a safe magnetic field for any exomoon.
3. If said exomoon is on the backside of the habitable zone or even just slightly beyond it. long day/night cycles are not a problem. The moon won't fry due to the distance from the star and heat generated by gravitational forces of the host planet will keep it warm during long nights. Also, Tidal locking means NO rotation on AXIS, the rotation of the exomoon around the host planet would not be affected. The rotation of the exomoon around a host planet is what would create the moon's day/night cycle! The rotation of the host planet in a slightly eccentric orbit (25% or less) would generate a seasonal pattern, otherwise the moon would become totally tropical or too warm for humans!
4. I agree with you 100% on this one, Exomoons will be hard to spot, but not impossible!

 

[tweldy]

The one thing about astronomy that holds to be true is that we consistently discover the unforeseen. I hope that life is found somewhere other than Earth in my lifetime and I will be greatly pleased if its somewhere no one expects it. Not premised on anything other than intuition, but I suspect geological activity to be more important for life than almost anything else. Chemistry is fundamental to life as we know it, but we've discovered extremophiles that defy the notion that life is biased such that it can only exist with a very narrow chemistry. I would be less surprised to find life on Titan than Mars.

 

[Yuri_Armstrong]

As of now I think there are only two candidates for Earth-like planets, Gliese 581 d and GJ1214 b. Hopefully we will discover more candidates and study them so we can understand their conditions better. I'm just glad we don't live in one of those rogue star systems that float between galaxies. Interstellar observations wouldn't even be possible for them! We are quite lucky to have such an abudance of stars within 40 light years, and it stands to reason that since we are in a galactic habitable zone at least one of our neighbors should posses a planet that also has life.

 

[Sycamorefan]

Hi Yuri ! Good to see back on this thred!

As of now I think there are only two candidates for Earth-like planets, Gliese 581 d and GJ1214 b

I'm not familiar with GJ1214 B, What class of star is GJ1214? No, I haven't keeped up with all the latest exoplanet finds of the last year or so... as you can tell! :?: :?:

 

[Yuri_Armstrong]

Gliese Jahreiss 1214 is an M4.5 red dwarf about 40 light years away from us. Its surface temperature is about 3,000 K.

 

[Sycamorefan]

GJ1214 is interesting! .91g surface gravity, high pressure atmosphere, 120-280 degree temps(Celsius) it reminds of a description of Venus in the distant past before it went totally wrong. Which means like Venus, it could have developed hardy lifeforms! I think this one is a VERY good candidate for low- level life forms! Thanx Yuri

 

[Yuri_Armstrong]

No problem. I'm looking forward to even better candidates than these and more research into their actual conditions.

 

[Sycamorefan]

Amen Yuri! I'm really looking forward to some form of life being discovered somewhere other than Earth! In fact, I'm almost 99% sure we will find microbial life on Mars if we check all the sites where probes from Earth have already landed. They will find native Martian Microbes or Earth Microbes that have contaminated Mars, assuming they Weren't already the same thing! If NASA isn't careful, the will seed life on Europa Too, again assuming life isn't already there!

 

[3488]

Hi Sycamorefan,

Great points.

I suspect any native microbial life on Mars is deep underground, well away from the surface, where uv radiation from the Sun is sterilizing (despite average solar incidence being only 44% as on Earth), where it is consistantly warmer with the increased likihood of liquid water & disolved minerals.

Any life on the surface will almost certainly be contamination sent by us from Earth.

Europa, I think is a dead horse. Fascinating planetary body in it's own right for sure, but Europa is so embedded within the lethal Jovian radiation belts that the icy surface is about as unfriendly as could be regarding life.

Not to mention sulphuric acid contamination on Europa's surface from neighbouring Io's volcanoes. There may be pockets of liquid water under the surface that could host microbes, but I think the notion of life there per se as well as a subsurface ocean is just flogging a dead horse.

Any current life off Earth IMO is well outside of the solar system.

Andrew Brown.

 

[Yuri_Armstrong]

I thought water and ice were two very good protections against the Jovian radiation?

 

[3488]

They are indeed, I was referring to the actual exposed surface of Europa.

Sorry for the misunderstanding.

Andrew Brown.

 

[Yuri_Armstrong]

I agree, the surface is most likely devoid of any type of life. The best hopes are in the hypothetical sub-surface ocean, especially around deep sea vents. Is there any hope for macroscopical life there? Or would it only be microbes clustered around the vents?

 

[marsbug]

I was under the impression that the Galileo magnetomometer readings had provided some evidence for the sub-surface ocean on Europa?

The European ocean floor will have been a fairly stable environment for billions of years by all accounts- not much pressure to evolve towards multicellular life. But look at under sea vents on earth: plenty of macroscopic forms there! So I'd suggest that there is hope.

 

[kk434]

Back in the year 2000 there was a lot of excitement about europa, Galileo was orbiting close to it and there was a consenssus that there is a liquid ocean under the ice, however the ice found to be very thick and practicly inpenetrabale. So a lot of the focus shifted from europa and the Europa orbiter scheduled for launch 2003 was cancelled. If a future orbiter confirms the oceans existence/age and it is found to be bilions of years old there is a very good chance for multicellar life, even a slight hope for fish like creatures.

 

[TheAnt]

I voted 3, now I did read the question as finding one duplicate of Earth = one with the right temperature range, oceans, continents. And finally, one oxygen & nitrogen atmosphere indicative of at least microbes producing the oxygen.

Now some have posted about the possibility of finding Earth-like moons around gas giants, I can say I share your enthusiasm for that possibility. But in that case one would not only have to separate the light of the star from the planet, but also the light of the moon for the gas giant it orbits around.
And that combination of problems make me think that whenever we find one truly Earth like planet, the first one found will be in a separate orbit around its star - simply because one such will be somewhat easier to detect.

As for moons that are somewhat like planets. We have Titan as the best example.
But even though this moon is in our own solar system, we are unable to tell if the chemical imbalance (the reported lack of hydrogen and ethane) might be caused my some sort of life, or is just due to a chemical process we don't understand yet.

Then we have the example of Europa, and even though we are almost certain have liquid water (in one form or other, one ocean or at least hot-spots) below the surface. It will not be possible with current technology to tell that from lightyears away.

The example of Europa is an interesting one for another reason. A planet of this type, larger than Europa and closer to its sun, but basically made up in the same manner could cause a false positive.
The ice on the surface would slowly sublimate and UV-radiation would split up the water molecules to hydrogen and oxygen. The hydrogen would be lost to space, while keeping the oxygen.
And so we would end up with a planet that seemingly looks lifebearing but it isnt.

With that situation we could very well end up announcing that 'we found a second Earth, but one that was unlucky to be in one iceage right now' - whereas it actually was just a case of chemistry at work.

Yet even if it would be ice cold and lifeless, it wouldn't be a bad place for one arctic guy like me to be on, if I only knew it was out there I be the first to fire up the engines of the FTL engine I built in my home. (Using nothing more than common household items like cardboard and superglue.)

 

[EarthlingX]

http://www.universetoday.com : Scientists Predict Earth-Like Habitable Exoplanet Will Be Found in 2011

Sep 15th 2010

by Nancy Atkinson


An artist’s impression of Gliese 581d, an exoplanet about 20.3 light-years away from Earth, in the constellation Libra.

Two astronomers have written a paper and say that the first Earth-like, habitable exoplanet will be announced in May of 2011. Do they have inside information, a crystal ball, or amazing powers of prediction? No, they base their projection on math and trends from the past 15 years of exoplanet discoveries. And if the discoveries continue at their present rate, the researchers say next year is the year of the long awaited holy grail of finding another Earth-like planet out in the cosmos.

Samuel Arbesman from Harvard Medical School in Boston and Gregory Laughlin at the University of California, Santa Cruz take a scientometric approach to their prediction. Scientometrics is the science of measuring and analyzing science, and is often done using bibliometrics which is a measurement of the impact of scientific publications. Arbesman and Laughlin said this type of work highlights the usefulness of predictive scientometric techniques to understand the pace of scientific discovery in many fields.

Read the paper: “A Scientometric Prediction of the Discovery of the First Potentially Habitable Planet with a Mass Similar to Earth.”

Additional Source: Technology Review Blog

 

[StarRider1701]

Hi Sycamorefan,
Europa, I think is a dead horse. Fascinating planetary body in it's own right for sure, but Europa is so embedded within the lethal Jovian radiation belts that the icy surface is about as unfriendly as could be regarding life. Andrew Brown.

Sure the surface of Europa will very likely be devoid of life, considering that it has no atmosphere. However, since we've noted guysers spraying out from cracks in the ice that indicates that Europa is still volcanically active and that there is water under that ice. Given these two factors, I'd be willing to bet that we not only find life, but complex life in the waters of Europa.

 

[Galacticexplorer]

Planets are commonplace in the Universe.It would be foolish to think they will not find earthlike planets to be commonplace.

 

[bdewoody]

Planets are commonplace in the Universe.It would be foolish to think they will not find earthlike planets to be commonplace.

It's one thing for them to be common place which they very well may be but whether we will ever have the capability to find any is another question. Unless such a planet is within 50-100 LY I doubt that we will ever locate one.