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Author Topic: Kepler orbital telescope finds 5 new exoplanets.  (Read 1866 times)

justboatonic

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Kepler orbital telescope finds 5 new exoplanets.
« on: January 04, 2010, 09:27:25 PM »

http://www.nasa.gov/mission_pages/kepler/news/top_story_contd.html

However all these 5 worlds are 'hot jupiters' and orbit their parent star between 3 and 5 days because they are so close to them. Once again, disappointingly, these worlds add further evidence that our solar system is unique in having 4 rocky worlds near the Sun and larger gas giants orbiting a lot further out.

Not one of the exo solar systems yet discovered is ordered like ours. Not one of the exo solar systems discovered todate has a planet in the 'habitable zone.' Not one of the 400 odd exo planets so far discovered is the size of Earth.

Keppler has the ability to find these rocky Earth size planets. It will sample over 150,000 stars in its search to find Earth 2 over the next 3 years. If it doesnt start finding Earth size planets in the habitable zone of these sampled stars then, it will become increasingly difficult, almost impossible in fact, for scientists to argue anything other than our solar system is looking more and more unique.
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dodgy geezer

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Re: Kepler orbital telescope finds 5 new exoplanets.
« Reply #1 on: January 04, 2010, 09:48:01 PM »

http://www.nasa.gov/mission_pages/kepler/news/top_story_contd.html

However all these 5 worlds are 'hot jupiters' and orbit their parent star between 3 and 5 days because they are so close to them. Once again, disappointingly, these worlds add further evidence that our solar system is unique in having 4 rocky worlds near the Sun and larger gas giants orbiting a lot further out.



It's a lot easier to find a gas giant right next to a sun with an orbital period of a week or less. And since Keppler is using the transit dimming technique, to find any planets in the habitable zone for a Sol-sized star will take at least one year. Kepler has been launched less that 9 months, and cannot have been providing data for longer than 6 months.

So this provides no evidence whatsoever that Earthlike planets are rare. You will only be able to say this in Spring 2012, if no rocky planets have been found by then....
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justboatonic

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Re: Kepler orbital telescope finds 5 new exoplanets.
« Reply #2 on: January 04, 2010, 10:34:58 PM »

It's a lot easier to find a gas giant right next to a sun with an orbital period of a week or less. And since Keppler is using the transit dimming technique, to find any planets in the habitable zone for a Sol-sized star will take at least one year. Kepler has been launched less that 9 months, and cannot have been providing data for longer than 6 months.

So this provides no evidence whatsoever that Earthlike planets are rare. You will only be able to say this in Spring 2012, if no rocky planets have been found by then....

Not quite correct in your summation DG.

Kepler is specially created and setup to find Earth size planets. This is its 3 year mission objective. It is not just to search for exo planets. The CCD's on Kepler have been designed to make the telescope spot small planets the size of Earth. The fact it has detected hot jupiters, shows the telescope is working properly. Once again, hot jupiters have been found and not the smaller planets. Kepler is capable of finding Earth size planets from the start although the mission requirements are that 3 transits are required for the scientists to absolutlely confirm the transit of an Earth size planet.  Kepler can however spot such an object with 1 transit.

What is important here is not just the size of the new 5 planets but their positioning relative to their parent star. Over 400 exo planets found and virtually without exception, all mainly hot jupiters which orbit very close to their parent star. The vast majority of these exo planetary systems now found, have massive planets close to the star which means it is virtually impossible for small rocky planets the size of Earth could have formed in each of those star's habitable zone.

This in turn is adding more and more weight to the fact that the planetary order of our solar system is not the norm and tending towards uniqueness.

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dodgy geezer

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Re: Kepler orbital telescope finds 5 new exoplanets.
« Reply #3 on: January 04, 2010, 11:01:07 PM »


Not quite correct in your summation DG.....


Ah, well, it's not actually my summation.I must confess that I looked a few things up.  Kepler has been up since March, but I understand the latest announcement was about work done on the first six weeks of data - so there really is very little chance that an earth-like planet on a 50-week orbit will be found in this early data. The systems which will be found early were predicted to be the 'hot Jupiters', and there they are. The requirement to wait three years is not mine, it is noted in the official NASA press release which accompanied the launch:

"...The first planets to roll out on the Kepler "assembly line" are expected to be the portly "hot Jupiters" -- gas giants that circle close and fast around their stars. NASA's Hubble and Spitzer space telescopes will be able to follow up with these planets and learn more about their atmospheres. Neptune-size planets will most likely be found next, followed by rocky ones as small as Earth. The true Earth analogs -- Earth-sized planets orbiting stars like our sun at distances where surface water, and possibly life, could exist -- would take at least three years to discover and confirm..."

You will find that here - http://science.nasa.gov/headlines/y2009/06mar_keplerlaunch.htm?friend

Earth-like planets may be rarer than we hope, but NASA seem to have anticipated your concern by suggesting that it is premature to say so on the basis of a 6-week scan for likely candidates....
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justboatonic

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Re: Kepler orbital telescope finds 5 new exoplanets.
« Reply #4 on: January 04, 2010, 11:17:03 PM »

Ah, well, it's not actually my summation.I must confess that I looked a few things up.  Kepler has been up since March, but I understand the latest announcement was about work done on the first six weeks of data - so there really is very little chance that an earth-like planet on a 50-week orbit will be found in this early data. The systems which will be found early were predicted to be the 'hot Jupiters', and there they are. The requirement to wait three years is not mine, it is noted in the official NASA press release which accompanied the launch:

"...The first planets to roll out on the Kepler "assembly line" are expected to be the portly "hot Jupiters" -- gas giants that circle close and fast around their stars. NASA's Hubble and Spitzer space telescopes will be able to follow up with these planets and learn more about their atmospheres. Neptune-size planets will most likely be found next, followed by rocky ones as small as Earth. The true Earth analogs -- Earth-sized planets orbiting stars like our sun at distances where surface water, and possibly life, could exist -- would take at least three years to discover and confirm..."

You will find that here - http://science.nasa.gov/headlines/y2009/06mar_keplerlaunch.htm?friend

Earth-like planets may be rarer than we hope, but NASA seem to have anticipated your concern by suggesting that it is premature to say so on the basis of a 6-week scan for likely candidates....


NASA will like the scientific community always err on the side of caution. Kepler could already have detected an Earth size planet. However NASA would not confirm this until another 2 transits had been seen.

But, my point about Earth size planets being rare is due to the number of hot jupiters that have been found. The majority of exoplanets are such. There is a paper by Fogg and Nelso which suggests, in simulations, Earth size planets could form after a gas giant had passed from the far reaches of a solar system to its position of a hot jupiter. However, this would leave any such Earth size planet that formed in the habitable zone, unprotected from meteors or asteroid impact as Jupiter kind of protects our Earth.

Other papers also suggest where an Earth size planet forms beyond the orbit of a hot jupiter after the hot jupiter has migrated to its position, resonances nearly alway end with the ejection of the Earth sized planet from that solar system.

http://www.universetoday.com/2009/11/23/hot-jupiters-bully-super-earths/

The conclusion being that Earth size planets may form in the habitable zone after a hot jupiter migration but that the Earth size  planet always ends up being ejected from the solar system.
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dodgy geezer

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Re: Kepler orbital telescope finds 5 new exoplanets.
« Reply #5 on: January 05, 2010, 12:20:46 AM »


NASA will like the scientific community always err on the side of caution. Kepler could already have detected an Earth size planet. However NASA would not confirm this until another 2 transits had been seen.

But, my point about Earth size planets being rare is due to the number of hot jupiters that have been found. The majority of exoplanets are such. ...

The paper you cite indicates that close orbit 'hot jupiters' cannot exist with a stable rocky planet at about 1 Au orbit. I haven't looked at it, but it seems a reasonable hypothesis.

However, what that means is that earth-like planets probably don't exist on most the stars we have been able to identify as planetary so far. That is not necessarily most of the planetary systems. My point is that the techniques we use for planet detection at the moment only work well with big planets close to their suns - these produce the largest wobble or dimming signal. So of course we find these hot jupiters first. Kepler is the first experiment which is theoretically capable of detecting earth-type planets, and even this is going to find a lot of hot jupiters before it finds an earth.

No one knows how common earths might be. There still might be lots of them - finding the hot jupiters first is only to be expected. And note that we believe there is a habitable zone for satellites of gas giants as well - Europa is a nearby example. Even working to its limits Kepler will not detect these. So I think there are still grounds for considerable optimism. After all, we have had several environments in our system capable of supporting protoplasmic life, and our orbits are also unstable - Mercury is likely to go before the Sun expands, and it may take the Earth with it...         
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warspite

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Re: Kepler orbital telescope finds 5 new exoplanets.
« Reply #6 on: January 05, 2010, 11:00:08 AM »

do I have time to post some more?  :D
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dodgy geezer

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Re: Kepler orbital telescope finds 5 new exoplanets.
« Reply #7 on: January 05, 2010, 11:49:01 AM »

do I have time to post some more?  :D

You have some more planets? If so, please send them to:

The British Astronomical Association,
Burlington House
London

..making sure they are wrapped carefully, and enclosing a stamped, addressed envelope if you would like them returned. We recommend using Registered Mail should your planets contain anything valuable, such as Helium-3. If there are any life-forms on the planet, your attention is drawn to the Royal Mail regulations for sending live animals through the post...
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polaris

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Re: Kepler orbital telescope finds 5 new exoplanets.
« Reply #8 on: January 05, 2010, 12:24:17 PM »


Dear All,

What mustn't be forgotten, and as the mere human brain has great difficulty with, is that space and 'everything' is infinite... it is timeless, it is absolutely incalculably infinite, it does not stop, and it has an infinite number of galaxies and star systems etc., etc., etc.. There is no limit, indeed, it doesn't matter how far one goes, it is absolutely impossible to get to the end of it........!!! - the end of it will never ever ever be reached. Whatever 'we' see from Earth, and whatever we might shoot into space to look further, is so microscopically small that it is irrelevant in the grand scheme of things (though obviously useful for 'generalising', and just experimenting with 'our' use getting out into our tiny bit of local space and getting to know it a bit. Ok, we have all heard of wormholes and other similar 'possibilities' that 'might' transport over huge distances, but, even if found and determined, these will still never ever get to the end of 'the void'... we then move onto/into 'dimension parallels' obviously, but we won't go down that route for now!

Regards, Bernard
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dodgy geezer

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Re: Kepler orbital telescope finds 5 new exoplanets.
« Reply #9 on: January 05, 2010, 02:01:43 PM »

What mustn't be forgotten, and as the mere human brain has great difficulty with, is that space and 'everything' is infinite... it is timeless, it is absolutely incalculably infinite, it does not stop, and it has an infinite number of galaxies and star systems etc., etc., etc.. There is no limit...

"..Current estimates place the size of the Universe at 93 billion light years across, but Dr Alan Penny, a researcher at the University of St Andrews, believes Kepler observations of a small selection of Cepheids may change this value by a few percent. When making precision observations of a very precise stellar period-brightness relationship, it's nice to be able to use the most precise instrument you can lay your hands on..."

http://www.universetoday.com/2009/04/14/kepler-will-be-used-to-measure-the-size-of-the-universe/
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polaris

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Re: Kepler orbital telescope finds 5 new exoplanets.
« Reply #10 on: January 05, 2010, 03:46:23 PM »


Dear Dodgygeezer,

Quite right. The development of programmes, instruments, and theory to determine space distances is indeed important, but, to use the keyword, "estimates", that is all they will be for quite some time to come. I know I generalise, and I know figures for near distance objects/planets are pretty accurate, but those far beyond are based on light, and who know's what might interupt/disrupt such figures - granted though, the figures are as accurate as they are going to be for many years to come, and it is no small achievement just to have reached the present highly complex theories that are used... another 100 years, well, who knows what will develop... unfortunately (or fortunately!?), we won't be around to know/hear the answers! >>:-( :}

Regards, Bernard
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justboatonic

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Re: Kepler orbital telescope finds 5 new exoplanets.
« Reply #11 on: January 06, 2010, 04:23:43 PM »

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