Searching for Earth Like Planets

[us.2u]

In 2007 NASA will launch a spacecraft named Kepler which will search for extra- solar planets it's telescope can scan 100,000 stars every 15 minutes if a planet passes in front of the star it's brightness will dip & kepler will detect it. Scores of extra-solar planets have been found already,but are gas giants like Jupiter.Kepler will be able to detect small Earth like planets....

[ed84c]

so how do they know wheter or not its earthlike?

[5614]

if you've ever studied space photography then the planets hundreds of light years away are not that visible enough to tell if it has water or not!

 

presumably the craft would have to have some kind of other sensors, however as it is being launched in 2007 not all details may be available yet.

[us.2u]

Thank-you 5614 I've just relayed NASA'S intentions; how they can detect planetary resources I do not know but I'm sure NASA will be happy to explain...

[TimeTraveler]

My impression is that they will be able to detect terrestrial planets and Earth-sized planets. That can be considered more Earth-like than what we can currently detect, however I don't think they will be able to detect water and atmosphere's.

 

Part of the mission also involves detecting distances of these planets, if there is a Gas giant harboring a terrestrial planet in a similar fashion that takes place in our solar system that will raise cause for further observation on that particular system.

[swansont]

This is just a guess, but you could detect a water absorption feature as the planet transited the star. This was alluded to in the preparation for the transit of Venus last June.

[Ophiolite]

In another thread I notd that Using telescopes in Earth orbit planets could be searched for using direct detection methods. Stellar coronagraphs can be used to supress the light from the planet's parent star making detection easier. There is a higher probability of detecting planetary companions around nearby stars in the infrared portion of the electromagnetic spectrum. This is due to the fact that the star to planet flux ratio is less in this region of the spectrum than in the visible. To separate a planetary companion from its primary stellar halo, one must use a telescope (or array of telescopes) with an aperture (or baseline) B such that r/D is greater than or equal to the wavelength at which the observation is being carried out divided by the aperture (or baseline) of the telescope (or array of telescopes).

The link I quoted from may be found here:

http://www.scienceforums.net/forums/showpost.php?p=113408&postcount=68

 

Martin followed up with detailed information, in the following post here:

http://www.scienceforums.net/forums/showpost.php?p=113505&postcount=69

[Encrypted]

What's the problem with having jupiter sized earth like planets?

 

Even if we did find such planets, what would we do with the info, since we dont have means of space travel sufficiently fast enough to take us to those planets.

 

In my opinion: pointless waste of money. Maybe we should focus more on pluto. Or develop better propulsion systems.

 

Encrypted

[Ophiolite]

What's the problem with having jupiter sized earth like planets?

You certainly cannot have a Jupiter sized Earth like planet. [We shall ignore the obvious fact that if it is like Jupiter in size it is already very un-Earth like.]

 

The bulk of Jupiter is made up of low density gases. You want to assemble a rocky-iron planet' date=' without these gases. The reason the Earth lacks these is that it was formed close to the sun (93 million miles is next door) and they could not condense in quantity. Those that did were progressively lost because of the weak gravitational pull. There was not enough material in the inner solar system to make anything even approaching the size of Jupiter from rocky-iron material. From what we know of other systems this would also be true.

So, what if the planet formed further out and migrated inwards? Well, it would retain tthee lighter gases, so you would end up with a super-Jupiter with a really big rocky-iron core. Heh! Guess what? Lots of the planets we have found are close in super-Jupiters.

 

Even if we could overcome these problems, you now have a planet where you would weigh several times your weight on Earth. Hardly earthlike.

 

And plate tectonics - the key to the Earth geological character - simply could not function in an earthlike manner.

Even if we did find such planets, what would we do with the info, since we dont have means of space travel sufficiently fast enough to take us to those planets.

I think you are refering to truly Earth like. They would:

Improve our understanding of planetary and system formation

Give us a figure for how common they are, and therefore improve our estimates for the abundance of life.

Identify targets for SETI.

 

Not a waste of money at all.

[[Tycho?]]

What's the problem with having jupiter sized earth like planets?

 

Even if we did find such planets' date=' what would we do with the info, since we dont have means of space travel sufficiently fast enough to take us to those planets.

 

In my opinion: pointless waste of money. Maybe we should focus more on pluto. Or develop better propulsion systems.

 

Encrypted[/quote']

 

Why in the world would be focus more on pluto instead of finding earth sized planets? Pluto is a ball of ice. And better propulsion systems are being tested all the time.

[us.2u]

Outer planets were thought to be too cold & dark to host life but by finding creatures at the bottom of our own oceans here on Earth we now realise life is capable of existing in these conditions so by sending out probes we can analyze images & send back soil samples & also search for radio signals still searching for ETI also thank-you Ophiolite for explaining how space telescopes work I for one look forward to the launching of NASA's Kepler telescope to be launched in 2007....

[Encrypted]

Hmmm...ic.

 

Thankyou very much ophiolite for explaining why jupiter-sized earth like planets could not exist. But then again: mars is earth sized aproximately, and so is venus. Size means nothing....

I think by earth like.....the author of this thread means planets able to support life.....life could evolve on a planet whose gravity is stronger than earth's. Plus....we have found life forms on the bottom of our oceans that live near volcanoes...and i'm not sure about this: some of them use sulphur like how we use oxygen....i remember a friend of mine telling me that once.

 

I think lots of planets would fit in that sort of description: lots of volcanoes, sulphur etc. Or do you mean that SETI is the search for extra terrestrial intelligence that is human like? And do you also mean by earth like planet: nice small little planet with vegetation and lots of water?

 

Who said life could not exist on a ball of ice?

 

Not enought money is spent on propulsion systems.

As for SETI.......what would we do if we did find life?

Again: Even if we did find life....no propulsion systems good enough....i mean we cant even reach pluto.

 

Life could be in any form shape or size. It could exist in many places. What little we have seen in one planet out of a google number of planets does not set the rules for biology.

[us.2u]

Looking further into the future spacecraft will use new engines one of these they have already worked on ,the ion engine has already been tested on unmanned missions.The U.S.A. intend to send Astronauts back to the moon in the year 2020 & then to Mars...

[Comandante]

Thank-you 5614 I've just relayed NASA'S intentions; how they can detect planetary resources I do not know but I'm sure NASA will be happy to explain...

 

NASA will explain more deeply when Kepler mission comes to play but in the meantime they have already explained a few things; they consider earth-like planet a planet that is in size similar to our earth and that there is a jupiter sized planet which will be a shield for that earth-like planet, now i'm not sure if they will be able to detect anything else besides that (what else can they possibly detect using only transit method? I was at first thinking of temperature, but doesnt sound like a possibility...) but you can have a look at this story: http://planetquest.jpl.nasa.gov/Kepler/kepler_index.html

[Dave]

Maybe they can use some kind of spectrographic analysis? I'm only guessing here, obviously

[us.2u]

Thanks Sysco for that link that was very interesting I'm looking forward for NASA's new discoveries....have you looked at the above link Dave also I'll look around for some more info & if lucky relay back cheers...P.S. has anyone got any info on NASA's new ION engines?...us.2u

[ecoli]

You certainly cannot have a Jupiter sized Earth like planet. [We shall ignore the obvious fact that if it is like Jupiter in size it is already very un-Earth like.]

 

The bulk of Jupiter is made up of low density gases. You want to assemble a rocky-iron planet' date=' without these gases. The reason the Earth lacks these is that it was formed close to the sun (93 million miles is next door) and they could not condense in quantity. Those that did were progressively lost because of the weak gravitational pull. There was not enough material in the inner solar system to make anything even approaching the size of Jupiter from rocky-iron material. From what we know of other systems this would also be true.

So, what if the planet formed further out and migrated inwards? Well, it would retain tthee lighter gases, so you would end up with a super-Jupiter with a really big rocky-iron core. Heh! Guess what? Lots of the planets we have found are close in super-Jupiters.

 

Even if we could overcome these problems, you now have a planet where you would weigh several times your weight on Earth. Hardly earthlike.

[/quote']

 

They're looking for Earth-like planets. Not Earth clones. There looking for planets that could possibly support human life in the future. It's not a look-alike contest.

[us.2u]

Please forgive me if I have misinterpertated what Ophiolte is saying but I believe he was not stating NASA are looking for Eart like clones but planets that caqn support life as we know it like you suggested I think Ophiolite was maintaining planets like Jupiter could not possibly support life I think the size of an extremely large planet like Jupiter cannot be Earth like in it's gravity or gases but I do stand to be corrected if I am incorrect...

[Dave]

I think you're correct there, but you need to split up that gigantic sentence a bit

[Ophiolite]

us.2u is correct in his interpretation. I was responding to encrypted's query, "why can we not have Jupiter sized Earth like planets". I was trying to demomnstrate that was like saying "why can't we have a blue that is a nice red colour?"

They're looking for Earth-like planets. Not Earth clones. There looking for planets that could possibly support human life in the future. It's not a look-alike contest.

If they could support human life they will have to be, for the reasons explained in my earlier post, similar in size to the Earth, and at the right distance from their primary. In the Solar System only Earth truly fits the bill. Venus and Mars could have made it if their distances or early histories had been a little different.

The available choices to produce a viable, complex biosphere are probably quite restrictive.

[us.2u]

Well in 2007 let's all be enthralled by what the Keplar telescope relays to us in info. Sorry about the mammoth sentance earlier Dave forgot about the punctuatation,anyway never mind about that, I will be studying Nasa's & ESA'S plans up to the year 2014 this week; just a quick insight... in 2014 ESA'S Rosseta space probe is scheduled to encounter the comet 67p/churyumov-Gerasimenko & put a small lander on it's surface.

[Encrypted]

Well if that's the case, why are we looking so far, for something so close....

 

The moon, Mars, some of Jupiter and Saturn's moons.....all possibly habitable by humans.

 

Encrypted

[TimeTraveler]

Well if that's the case' date=' why are we looking so far, for something so close....

 

The moon, Mars, some of Jupiter and Saturn's moons.....all possibly habitable by humans.[/quote']

 

Reluctantly, I do agree. We seem to get ahead of ourselves sometimes when it comes to determining where the space budget money is spent. We cannot travel outside our solar system, heck we have not even traveled to the closest planet. If we find one or one-thousand earth like planets around other stars we will not be able to use anything from them, except know that they are there. I think the money could be better spent towards more important missions closer to home, such as mining asteroids, colonizing other worlds ect.

[ecoli]

ort human life they will have to be' date=' for the reasons explained in my earlier post, similar in size to the Earth, and at the right distance from their primary. In the Solar System only Earth truly fits the bill. Venus and Mars could have made it if their distances or early histories had been a little different.

The available choices to produce a viable, complex biosphere are probably quite restrictive.[/quote']

 

Oh, Gotcha

 

Could humans be able to adapt to gravity differences on different planets. Astronaughts that come back from trips have to get used to earth gravity again, so could humans do this on another planet? (provided the differeces are too great)

[RichF]

The things to check for are the are the stars spectral type, the star to planet distance, orbit and the planet size. A suitably sized planet within the "life zone" where liquid water can exist and has a "normal" orbit, I think that's what I think they're looking for.

 

JMO from what I remember.