Exactly what makes these guys so sure that this system doesnt have a massive gas giant to take the majority of Hydrogen left from the star formation 11 bil years ago and they cant see that gas giant because its in an orbit plane that doesnt cross the star to be noticed in our line of sight that their method depends to detect the 2 planets they did in that system. Would they be able to see Jupiter for example if they were looking at our system from a particular angle that still allowed earth passing to be noticed?

Jupiter has an orbital period of ~12 years. Kepler hasn't been running long enough to detect it.

Exactly my point, if their method would depend on noticing a crossing (even if it was possible to cross that line of sight cone), but also perturbations in orbit, ie frequency games that would take some time to be studied.


Plus exactly why something with 3g gravity at its surface, given the parameters used, would collect all hydrogen? It could still lose a lot of it after 11 bil years if it hadnt taken an enormous pressure liquid metallic form etc. It might even have had enormous internal heat released for a great period making it even more likely for the hydrogen to escape to space plus all kinds of unknowns really for that system.

Hey Masque,

Doesn't the kepler design require this hypothetical gas giant to be within a few degrees of the orbital plane of the rocky planet they just discovered? Kepler needs to be viewing the system edge-on so if they detect the rocky planet then the only limiting factor to detecting the gas-giant would be it's orbital period as kepler protocol requires 3 "hits" and it's been active for only a few years so objects with orbital periods > 5/3 years would slip through kepler's net.

Yes this is what i have been talking about. But the fact a period can also be longer than the operation of the system is an issue. However i need to study a bit more if they have other ways to estimate such case by looking at how the star spectrum changes with time (if under the influence of another much smaller but still massive enough to matter object, like our sun does with Jupiter). By that i mean you could be observing the star come and go (on top of whatever relative velocity we have with our system- take all this out). Such observation may not require the full period to be established if their accuracy is significant. You do not see the giant but you guess its existence from that trajectory of the star.

As for the Jupiter plane i was talking about falling outside the line of sight that Kepler is observing the star, in general an object that is say 5 au away from a star and only 1 deg different than say some plane of observation, is by the 5 au distance already away by some 13 mil km away from where it should have been to be observed passing in front of the star surface (at eg 0 deg plane ) and many stars have much smaller radius than that anyway so we get no transit. So in general we wont be that lucky to catch the giant crossing the star surface (transit) and establishing a very predictable optical influence pattern.

Also imagine if you view a solar system from a direction that is almost vertical to its plane. In that case you will never get to see any planets although they are there. You may be able to see the star though move periodically around the barycenter and guess that way the other gas giants' existence. So the Kepler method is catching planets in a way that is not complete (ie cant see everything in the system, only a few of its planets initially) but may over time improve as more data is collected for each system and things are combined to form more complex "pictures" of what is going on (reverse engineer the motions), especially if some of these measurements can be very accurate due to smart optics.


We could read their paper and understand better their approach of course.
eg
http://arxiv.org/pdf/1105.4647v1.pdf

Don't they also wait for at least 2 planet orbits before being confident enough to say there is a planet. So effectively if a planet had a 5 earth year orbit, the earliest we would ever confirm it would be 10 years. And that is if we got lucky and the planet passed right after we started experimenting.

well it would be just over 5 years as it could be sighted the first time, and then seen again 5 years later.

Maybe I didn't write it clearly in my post.

I believe that Kepler waits for 3 transits of the planet between us and their sun (i.e. two orbits of the planet). This is in order so that there are no anomalies in the data collected. i.e. if waits until it has observed the same dimming of the star 3 times and checks that the time elapsed between dimming 1 and 2 = time elapsed between dimming 2 and 3 to confirm there is a planet.

This helps to throw out any dodgy data caused by 'other' things, which is a fair few results due to the dimming being of such a small magnitude.

Though I haven't read a lot about it recently, so they may have fine tuned it that they only need 2 transits (i.e. one orbit).

Announcement from JPL:

NASA Telescopes Find Clear Skies and Water Vapor on Exoplanet

http://www.jpl.nasa.gov/news/news.php?release=2014-322

Portion of above linked article given below:

Astronomers using data from three of NASA's space telescopes -- Hubble, Spitzer and Kepler -- have discovered clear skies and steamy water vapor on a gaseous planet outside our solar system. The planet is about the size of Neptune, making it the smallest planet from which molecules of any kind have been detected.

"This discovery is a significant milepost on the road to eventually analyzing the atmospheric composition of smaller, rocky planets more like Earth," said John Grunsfeld, assistant administrator of NASA's Science Mission Directorate. "Such achievements are only possible today with the combined capabilities of these unique and powerful observatories."

Clouds in a planet's atmosphere can block the view to underlying molecules that reveal information about the planet's composition and history. Finding clear skies on a Neptune-size planet is a good sign that smaller planets might have similarly good visibility.

"When astronomers go observing at night with telescopes, they say 'clear skies' to mean good luck," said Jonathan Fraine of the University of Maryland, College Park, lead author of a new study appearing in Nature. "In this case, we found clear skies on a distant planet. That's lucky for us because it means clouds didn't block our view of water molecules."



The planet, HAT-P-11b, is categorized as an exo-Neptune -- a Neptune-sized planet that orbits the star HAT-P-11. It is located 120 light-years away in the constellation Cygnus (emphasis added). This planet orbits closer to its star than does our Neptune to our sun, making one lap roughly every five days. It is a warm world thought to have a rocky core and gaseous atmosphere. Not much else was known about the composition of the planet, or other exo-Neptunes like it, until now.

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The simple fact that the exo-Neptune is 120 light-years distance and we can get this type of information is significant.

One lap every 5 days? I would hope it is closer to its parent star than Neptune is to our star......

Some details about the above system;

http://media4.obspm.fr/exoplanets/ba...p?nom=HAT-P-11

en.wikipedia.org/wiki/HAT-P-11


The planet orbits a 0.8Ms star that is about 6.5 bil years old at only 0.05 Au distance in 4.89 days or 117 km/sec speed. It has 25 times the mass of earth and 4.6 times the radius. 1.2g surface gravity close to earth but its not a rocky surface and the rotation is so fast around the star that its centripetal acceleration is already over 10% of its surface gravity. But its a hell world in terms of receiving 90x times more radiation per unit area and time than earth from sun. So forget any chance for satellites that could look friendly at that distance.

I dont know if all this means now is that we can detect at least an earth size planet with water if it is properly placed to be spotted by this method within a distance of less than 26 light years ie 120/4.6. One must expect 300-3000 earth size rocky planets in such range but how many of them can be seen with this method is a good question (probably not even 5% of them).


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Non free will signature. 2+2 community, BruceZ, 2+2 leaders etc, all with your choices give back BruceZ and others you "chase" away to this discussion and the ones that will follow. We are all in this interactions learning game together.

http://news.yahoo.com/nasas-kepler-s...165844564.html

http://www.science20.com/news_articl...planets-151557

http://www.nasa.gov/press/2014/decem...on/#.VJN8jdFAA

"The newly confirmed planet, HIP 116454b, is 2.5 times the diameter of Earth and follows a close, nine-day orbit around a star that is smaller and cooler than our sun, making the planet too hot for life as we know it. HIP 116454b and its star are 180 light-years from Earth, toward the constellation Pisces."



"Despite a malfunction that ended its primary mission in May 2013, the Kepler spacecraft is still alive and working and its data has found a new "super-Earth".

NASA's Kepler spacecraft detected planets by looking for transits, when a star dims slightly as a planet crosses in front of it. The smaller the planet, the weaker the dimming, so brightness measurements must be precise and that requires maintaining a steady pointing. Kepler can't really do that any more, its primary functionality came to an end when the second of four reaction wheels used to stabilize the spacecraft failed. Without at least three functioning reaction wheels, Kepler couldn't be pointed accurately.

To compensate, engineers developed a strategy to use pressure from sunlight as a virtual reaction wheel to help control the spacecraft and achieve about half the photometric precision of Kepler when it was still fully functional. They believe they can not only continue Kepler's search for other worlds, but also introduce new opportunities to observe star clusters, active galaxies, and supernovae."

Another Earth-like planet found/detected from the Kepler Mission Data:

Earth like planet found

From above link:

Inching ahead on their quest for what they call Earth 2.0, astronomers from NASA’s Kepler planet-hunting spacecraft announced on Thursday that they had found what might be one of the closest analogues to our own world yet.

It is a planet a little more than one and a half times as big in radius as Earth. Known as Kepler 452b, it circles a sunlike star in an orbit that takes 385 days, just slightly longer than our own year, putting it firmly in the “Goldilocks” habitable zone where the temperatures are lukewarm and suitable for liquid water on the surface — if it has a surface.


The new planet’s size puts it right on the edge between being rocky like Earth and being a fluffy gas ball like Neptune, according to studies of other such exoplanets. In an email, Jon Jenkins of NASA’s Ames Research Center, home of the Kepler project, and lead author of a paper being published in The Astronomical Journal, said the likelihood of the planet’s being rocky was 50 percent to 62 percent, depending on uncertainties in the size of its home star. That would mean its mass is about five times that of Earth.


[NASA’s Kepler mission has discovered more than 1,000 confirmed planets orbiting distant stars.]


Such a planet would probably have a thick, cloudy atmosphere and active volcanoes, Dr. Jenkins said, and twice the gravity of Earth. Describing the planet during a news conference, Dr. Jenkins lapsed into lines from John Keats’s poem “On First Looking Into Chapman’s Homer”: “Then felt I like some watcher of the skies / When a new planet swims into his ken.”

The star that lights this planet’s sky is about 1.5 billion years older than our sun and 20 percent more luminous, which has implications for the prospects of life, Dr. Jenkins said.

“We can think of Kepler-452b as an older, bigger cousin to Earth, providing an opportunity to understand and reflect upon Earth’s evolving environment,” he said. “It’s awe-inspiring to consider that this planet has spent six billion years in the habitable zone of its star, longer than Earth. That’s substantial opportunity for life to arise, should all the necessary ingredients and conditions for life exist on this planet.”

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Could they identify something resembling Murica?

Rumor has it that an unconfirmed sighting of a duplicate Trump Tower was made. But this could well turn out to be the same type of mistake as the face on Mars. Time will tell.

https://www.nasa.gov/press-release/n...planets-around

There was a different story that had better details, but I couldn't find it again. It said "at least" 500 million years old, which sort of implies less than a billion. That means if there's any life at all, it's bacteria, at best. It also said only the inner 3 were tidally locked, which would make the others more habitable.

I changed the title of this long running thread to the more general theme of searching for habitable planets by any technological means. It was specific to the Kepler mission only, but an update was needed.

Howard now will have all information in one thread/place for his choice on establishing his exoplanet empire.