Earth-like planet when?

[medkhess]

Am responding to a posted question on Space.com. When are we likely to find an earth-like planet? I do believe we'll find something in next 5-10 yrs. But will we be ready?

 

[thalion]

Ready for what?

 

[mcbethcg]

Yes, we will be ready. It will be anticlimatic. <br /><br />An astronomer will first anounce that they have discovered an object that has the orbit.<br /><br />Then a few years later better techniques will indicate that it has the right size.<br /><br />Then a few years later better techniques will indicate that it has the right atmosphere.<br /><br />A century later it will be directly imaged with an even better telescope....

 

[mooware]

<font color="yellow">But will we be ready?</font><br /><br />Does it matter? If life exists elsewhere in the universe it doesn't hinge on if we are ready or not.<br /><br />What's that hide and seek thing? Ready or not, here I come.<br /><br />

 

[spayss]

Earth-like meaning what? It's all a matter of degree. Earth-size and 90 miles from a Sun-like star?<br /><br /> Is Venus Earth-like if found around another star? Mars?<br /><br /> Do you mean Earth-like in having a large Moon? <br /><br /> 99.9999999% of Earth has nothing to do with 'life' so is a planet 99.9999999 like Earth but with no life 'Earth-like'? Is a planet much less like the Earth (say Venus) but with life more 'Earth-like'?<br /><br /> Will we soon find a planet sort of like the Earth with life...NO. Certainly there's no technology capable of this type of determination available in the next few decades.

 

[gregoire]

Frankly it won't really matter much to most people IMHO, as it will probably be 100's or 1,000's of light years away. Too far away to be a threat, assuming it's even crawled out of the primordial goo.<br />

 

[robnissen]

"Will we soon find a planet sort of like the Earth with life...NO. Certainly there's no technology capable of this type of determination available in the next few decades." <br /><br />Not necessarily. In the next few decades we will have the capability to detect earth-like planets out to a few hundred light years, and we might have the capability to detect a substantial oxygen atmosphere. Any planet that had a substantial oxygen atmosphere would be an extremely good candidate for current life.

 

[najab]

><i>Any planet that had a substantial oxygen atmosphere would be an extremely good candidate for current life.</i><p>I'd go one further than that, if they were to find a planet with, let's say, a 10% oxygen atmosphere I'd say the question is how could it <b>not</b> be home to current life?</p>

 

[robotical]

And if there are traces of methane found in its atmosphere... <div class="Discussion_UserSignature"> </div>

 

[spayss]

No. We won't know if there is life or not and we won't know how Earth-like it is. We will have some educated guesses but it will be a LONG time before we will be able to say a planet in a far off solar system is Earth-like. We have no models other than the Earth. Deductive logic (nothing else could make an oxygen atmosphere) only goes so far in 'declaring' life on Earth-2.<br /><br /> It's already 2005, we've landed craft on Mars and STILL can't say absolutely that there is or isn't any life. Our remote technology to detect life on Earth-like planets hundreds of light years away is non-existent...and that assumes there are any such planets. All the more reason to put a pile of resources into such a fascinating endeavor. Looking for life elsewhere is the ultimate treasure hunt.<br /><br />

 

[silylene old]

<font color="yellow">And if there are traces of methane found in its atmosphere... </font> it would indicate that photoreductive processes might be operant.<br /><br />methane does not necessarily = life <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[najab]

I was considering a terrestrial planet only. Also, I don't think (please correct me if I'm wrong) that you'd get as much as a 10% oxygen atmosphere by a photodissociation mechanism.

 

[thnkrx]

The current best shot at locating an earth sized planet in a earth like orbit about another star would most likely be the Kepler satelite, slated for launch in 2007 (?). Supposedly, it should be able to spot planets transiting a star the size of Mars.

 

[jmilsom]

bobvanx used to have a great thread running on a NASA funded research project that was looking into putting a pinhole camera in space - theoretically capable of imaging earth-like planets around distant stars. Can't find it - can someone post again? <div class="Discussion_UserSignature"> </div>

 

[najab]

Hmm...then perhaps if there's a lot of oxygen, but not a lot of water vapor.

 

[najab]

Hmm...if our hypothetical planet had 10% oxygen and detectable amounts of methane, I'd wager that there's life. The reason being, of course, that methane wouldn't last long in an atmosphere with abundant oxygen! So something would have to be replacing it quite quickly.

 

[silylene old]

<font color="yellow">The reason being, of course, that methane wouldn't last long in an atmosphere with abundant oxygen!</font><br /><br />Photoreduction of CO2 on metal oxide dust catalysts (TiO2, for example) can replenish trace levels of methane.<br /><br />Now, if it were a water world (no metal oxides dust) and had methane in the atmosphere, this would just about eliminate the photoreduction mechanism.... <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>