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e·h·w·Stock post message.svg To-do:
  • Maybe another reference about history of gravitational microlensing method
  • Might like to modify the gravitational-lensing diagram slightly
  • Add something on HD 209458 b#Atmospheric water vapor
  • Add links perhaps with some discussion to similar articles The Fermi Paradox, The Rare Earth Hypothesis and The Many-body problem
  • A list of instruments/telescopes used to find exoplanets and an indication of how useful they have been and how many exoplanets they have found perhaps also their operational ranges
  • Think the article could have a better link to the planetary habitability article. Perhaps a synopsis of that article plus a see main article link.
  • Discussion of static magnetic fields e.g. Mercury in properties section
  • Atmospheric expansion of hot jupiters
  • neat real picture at [1] !
  • List of REAL exoplanet images.
  • A little more about polarimetry--which planet(s) have been studied that way?

How can an exoplanet be able to contain water[edit]

 For finding any theoretical explanation of mechanism which results production of water in planetary system see my works.

I give new approach for this case ,as you will see the chemical kinetic which produces generally water and ammonia and methane in outer part of solar system that contains three planets body together with some planet’s atmosphere and comets body are made now not remaining from first solar system nebula .--Akbarmohammadzade (talk) 06:50, 13 September 2013 (UTC) we were show that the solar CNO cycle produced particles with protons and electrons carried by solar wind are fouling on the outer part of system and make three famous molecules :methane and water and ammonia .--Akbarmohammadzade (talk) 06:50, 13 September 2013 (UTC)

Life on Exoplanets[edit]

In the paragraph dealing with life on exoplanets, someone educated in the field of biology and development of life on earth should say something about the fact that for earth, complex lifeforms emerged only after 4 billion years and chances are that conditions on any planet just take so much time too be just right for complex life to develop.

It certainly should be mentioned with this new hype regarding the new KOI superearth analog in the habitable zone. No life will be there, not even detectable oxygen in the atmosphere. That took primitive life on earth something like years. — Preceding unsigned comment added by (talk) 22:56, 19 February 2013 (UTC)

Well, while that sounds sensible, it is pure speculation. So, unless an RS made those speculations, it definitely does not belong in the article. Geo Swan (talk) 22:53, 24 July 2013 (UTC)
Also, with Creation Theory, who is to say it took billions of years to get where we are on Earth? Agreed that the 'unknown' does not need to be expanded in the article here. What would be a 'reliable source' on this anyway? — Just asking, Charles Edwin Shipp (talk) 12:32, 9 March 2014 (UTC)
On the other hand, a point could be made (in the article here) of the amazing creation of Earth (and plant, animal, Earthlings) and the delicate nature of our existence, supported by the Creator. As everyone may know, National Geographic Channel this evening features the new Fox science series “Cosmos: A Spacetime Odyssey”. President Obama will deliver the introduction. "Be there, or be square!" [2] FYI, Charles Edwin Shipp (talk) 12:41, 9 March 2014 (UTC)
Creationism is just pure religious bullshit that is not supported by any shred of evidence and falsified by tons of evidence. --JorisvS (talk) 12:48, 9 March 2014 (UTC)
While I tend to agree with regard to so-called "creation science", one need not be a dick about it (unless, of course, you're just a dick). Besides, I can't help but think that much of the information in this article will likewise seem like bullshit to future generations.-- (talk) 05:33, 18 April 2014 (UTC)
Can we please keep this discussion civil? David J Johnson (talk) 11:57, 18 April 2014 (UTC)

Alpha Centauri Bb[edit]

The existence of Alpha Centauri Bb has not been confirmed. I don't think it should be reported on this page until the evidence is more solid. Praemonitus (talk) 22:34, 7 September 2013 (UTC)

I've rephrased things to emphasize that there is doubt about its existence. There is also now a new section on Candidate discoveries which links to the article List of unconfirmed extrasolar planets. Astredita (talk) 12:30, 29 September 2013 (UTC)

KOI-172.02 paragraph in the introduction[edit]

Should this be removed and replaced with Kepler-62 paragraph as Kepler-62 planets turned out to be in the habitable zone? --Artman40 (talk) 11:54, 1 October 2013 (UTC)

Yes. The Kepler-62 planets are currently the best examples of almost earth-size planets in the habitable zone. Astredita (talk) 17:26, 9 October 2013 (UTC)

Number of Kepler candidates[edit]

According to NASA's [3], the number of Kepler candidates has increased to more than 3400 (if you discount the confirmed planets). In addition, exoplanet archive now lists a few detection methods which the planet discovery graphs have not taken account for. --Artman40 (talk) 22:00, 27 October 2013 (UTC)

Requested move[edit]

The following discussion is an archived discussion of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the proposal was moved. --BDD (talk) 22:35, 14 November 2013 (UTC)

Extrasolar planetExoplanet – Per Wikipedia:COMMONNAME. The term "Exoplanet" is used far more than "Extrasolar planet". See, for example, this google ngram graph. Q6637p (talk) 15:22, 7 November 2013 (UTC) Support move, more common and more concise. - WPGA2345 - 04:57, 8 November 2013 (UTC)

The above discussion is preserved as an archive of the proposal. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Word confusion[edit]

OK I fixed the wrong problem before, but now I see the real problem. "It is expected that there are many billions of planets in the Milky Way (at least one planet, on average, orbiting around each star, resulting in 100–400 billion exoplanets)." OK I looked up that there are about 400 billion stars in the Milky Way. Base on the information in the (), if it's true that each star has about 1 orbiting planet then it would be true to have 100-400 billion exoplanets. It is totally contradicted by the precedent statement. I know planets in Milky Way and 100-400 billion exoplanets are referring to exoplanets. I don't know about you guys, but many billions are not the same as 100-400 billion. To me, many billions mean 2-99 billions. "Many billions" should be change into "hundreds billion."Pendragon5 (talk) 04:43, 17 December 2013 (UTC)

It does not say "about 1 planet". It says "at least 1 planet". There could well be much more than 1 per star but we just don't know at this point in time. There could be 10 on average for all we know, and that seems quite likely to me. "Many" is an unspecific term and therefore suitable since we don't know exactly how many there are. "hundreds" is too specific because it suggests that the number is known to the accuracy that it is possible to say hundreds but it isn't known that accurately. There could very well be trillions of planets in the milky way. i.e. thousands of billions, not hundreds. But we don't know. Maybe there are less than a trillion. Maybe more. All we really know is that there are billions, lots of billions, many billions. Astredita (talk) 05:42, 17 December 2013 (UTC)
FWIW, I personally don't find "many billions" to be limited to "2-99". Usually "many" is pretty open ended. Rwessel (talk) 05:48, 17 December 2013 (UTC)
I've deleted the 100-400b bit because: "at least 1 planet on average per star with an estimated 100-400b stars" does NOT mean 100-400b planets. It means "at least 100-400b planets". However that isn't a useful sentence. Combining a lowest estimate for planets per star with a range of estimates for the number of stars does not produce a simple estimate of the total number of planets. Astredita (talk) 06:00, 17 December 2013 (UTC)
Use the refs "There are at least 100 billion planets in the galaxy, just our galaxy," says John Johnson 1 and Jonathan Swift 2. Jim1138 (talk) 06:03, 17 December 2013 (UTC)
Ok, I've rephrased it in that way. Astredita (talk) 06:24, 17 December 2013 (UTC)


"In many cases the semi-major axis is approximately the same as the distance between the planet and the star."


"In many cases the semi-major axis is approximately the same as the distance between the planet and the center of the star and to its surface."

I found the second version difficult to read. I'm not sure it is necessary for this sentence to specify the point on the star that the distance is measured from because the sentence is talking about approximateness. On the other hand the section as a whole is distinguishing between different points so perhaps the sentence should be reworded. Astredita (talk) 13:13, 19 February 2014 (UTC)

Maybe it should be reworded somehow. As you say, we're distinguishing between different points. Then we should try to be crystal clear to which point we're referring at any time. --JorisvS (talk) 13:41, 19 February 2014 (UTC)

New version: "If the sizes of the star and planet are relatively small compared to the size of the orbit and the orbit is nearly circular and the center of mass is not too far from the star's center, such as in the Earth-Sun system, then the distance from any point on the star to any point on the planet is approximately the same as the semi-major axis. However, when a star's radius expands when it turns into a red giant, then the distance between the planet and the star's surface can become close to zero, or even less than zero if the planet has been engulfed by the expanding red giant, whereas the center of mass from which the semi-major axis is measured will still be near the center of the red giant." Astredita (talk) 14:48, 19 February 2014 (UTC)

NASA Kepler telescope helps identify 750 new planets outside our solar system[edit]

Headline-1: Planet bonanza: NASA announces discovery of 715 new worlds

"NASA says its Kepler telescope has discovered a bonanza of 715 planets outside our solar system, pushing the number of planets discovered in the galaxy to about 1,700."

Headline-2: ‘We Almost Doubled Just Today the Number of Planets Known to Humanity’

" "Our galaxy is looking far more crowded and hospitable. NASA on Wednesday confirmed a bonanza of 715 newly discovered planets outside our solar system." "Scientists using the planet-hunting Kepler telescope pushed the number of planets discovered in the galaxy to about 1,700. Twenty years ago, astronomers had not found any planets circling stars other than the ones revolving around our sun."

Headline-3: NASA Scientists Discover 715 New Planets — Data From Kepler Space Telescope Suggests 4 Alien Worlds Have Potential for Life

NOTE: This is a subscription article: "NASA scientists announced Wednesday the discovery of 715 . . ." — Charles Edwin Shipp (talk) 14:30, 27 February 2014 (UTC)

Beta Pictoris[edit]

I see a picture/photograph of Beta Pictoris at the top of the article here.

Headine-1: Did two planets around nearby star collide? Toxic gas holds hints.

QUOTE: “This artist's impression of the Beta Pictoris system shows carbon monoxide gas permeating the star's dusty debris disc. Astronomers say this gas could be the signs of a massive collision of two icy, Mars-sized planets or constant collisions among a population of comets. (F. Reddy / NASA's Goddard Space Flight Center)” [Fascinating Los Angeles Times article.] — Charles Edwin Shipp (talk) 16:12, 9 March 2014 (UTC)

FWIW - *May* also be relevant as a way a planet can receive complex organic chemicals (starting materials for life - or even primitive life-forms themselves?) (per Panspermia, Abiogenesis and related) - ref details => < ref name="LAT_20140308">Khan, Amina (March 7, 2014). "Did two planets around nearby star collide? Toxic gas holds hints". LA Times. Retrieved March 9, 2014. </ref> AND < ref name="SCI-20140306">Dent, W.R.F.; Wyatt, M.C.;Roberge, A.; Augereau,J.-C.; Casassus, S.;Corder, S.; Greaves, J.S.; de Gregorio-Monsalvo, I; Hales, A.; Jackson, A.P.; Hughes, A. Meredith; Lagrange, A.-M; Matthews, B.; Wilner, D. (March 6, 2014). "Molecular Gas Clumps from the Destruction of Icy Bodies in the β Pictoris Debris Disk". Science (journal). doi:10.1126/science.1248726. Retrieved March 9, 2014. </ref> - in any case - Enjoy! :) Drbogdan (talk) 16:43, 9 March 2014 (UTC)

Breakup article[edit]

The article is intimidating in its current length. I think it would be much better as shorter articles. I noticed that the 'further reading' section is very long; could that be a separate article? Sanpitch (talk) 04:59, 14 April 2014 (UTC)

I don't think it is long enough. Many of the sections hardly say anything. I think it would be even worse as short articles - there are already dozens of very short Wikipedia articles on exoplanets which could be merged into this one. I've moved the further reading items into the sections of the article where they can be expanded upon. The study of exoplanets has hardly begun. I think the article will end up being very much longer than it is today. Astredita (talk) 12:30, 14 April 2014 (UTC)

For a shorter introduction to exoplanets there is the exoplanet section of the planet article. I've added a hat note to this effect. Astredita (talk) 15:26, 14 April 2014 (UTC)

I am happy that you're so passionate about Exoplanets that want to make a very detailed and extensive article. I also like Exoplanets. FYI, Wikipedia:Article Size says that for articles above 50kB of readable prose, one should consider moving parts of the article to other articles and replacing them with summaries. The Exoplanets page has about 63kB of readable prose, while Life has about 40kB and Astronomy has 36kB. From Wikipedia:What Wikipedia is Not we see that Wikipedia is not an collection of links, or scientific journal, or a means of promotion; the article is moving in that direction. I suggest that if you want it to be useful to other people (besides yourself and a few other enthusiasts) that you consider making it "as simple as possible, but not simpler." Sanpitch (talk) 03:15, 15 April 2014 (UTC)
The further reading items can be converted into prose over time so the article doesn't become just a collection of links. A few of the items were incorporated into the article prose today. Some of the sections probably will grow to the point that they will be split into separate articles. Astredita (talk) 20:12, 15 April 2014 (UTC)
It sounds like you agree that the article is too long and parts need to be split off. I'm glad to hear this. The article as it stands today is not that useful for the general audience. I do not think that your change of moving the further reading sections into the article helped, but exacerbated the "link list" nature of the article. Also, adding a link to the exoplanet section of planet sounds to me like an acknowledgement of the convoluted and messy nature of the article. I wish you the best as you work to clean it up.Sanpitch (talk) 20:54, 15 April 2014 (UTC)
That is not even remotely close to what I said. Astredita (talk) 21:47, 15 April 2014 (UTC)

You have pointed out that Wikipedia:Article Size says above 50kB of readable prose, one should consider moving parts of the article to other articles and replacing them with summaries. You also suggested the 'Further reading' section could be another article. However the 'Further reading' section was no prose just titles, i.e. the ultimate summarization of the content in those articles. So moving 'Further reading' elsewhere and replacing it with summaries is therefore nonsensical. Astredita (talk) 22:01, 15 April 2014 (UTC)

All I'm saying is that the article seems too long. I do not plan to contribute to this article other than via these comments; if you don't value my feedback, I will not hinder you further from growing the article size.Sanpitch (talk)

Sub-brown dwarf with planet or Rogue planet with moon[edit]

Even if MOA-2011-BLG-262 is a planetary-mass object that doesn't necessarily mean its companion should be called a moon. Free floating planetary-mass objects can form from interstellar clouds just like stars and brown-dwarfs do. In which case they are sub-brown dwarfs. The satellites of sub-brown dwarfs could be considered planets just as the satellites of stars and brown dwarfs are planets. That MOA-2011-BLG-262 has a companion makes it unlikely to be a rogue planet that has been ejected from orbit around a star. Although The Survival Rate of Ejected Terrestrial Planets with Moons by J. H. Debes, S. Sigurdsson suggests it's not impossible for ejected planets to hold on to their moons, so the presence of a moon doesn't necessarily mean the main object is a sub-brown dwarf. Astredita (talk) 14:21, 14 April 2014 (UTC)

NASA-TV (07/14/2014@2pm/et/usa) - Search for Life Beyond Earth.[edit]

NASA-TV (0714/2014@2:00-3:30pm/et/usa) - Panel of leading experts to discuss plans leading to the "discovery of potentially habitable worlds among the stars" => < ref name="NASA-20140710">Brown, Dwayne (July 10, 2014). "MEDIA ADVISORY M14-117 - Leading Space Experts to Discuss the Search for Life Beyond Earth". NASA. Retrieved July 10, 2014. </ref> - Enjoy! :) Drbogdan (talk) 13:40, 11 July 2014 (UTC)

FOLLOWUP - NASA VIDEO REPLAY - Space Experts Discuss the "Search for Life in the Universe" (86:49) at => - Enjoy! :) Drbogdan (talk) 12:50, 15 July 2014 (UTC)

Definition of exoplanet correct?[edit]

"An exoplanet or extrasolar planet is a planet that does not orbit Earth's Sun and instead orbits a different star, stellar remnant, or brown dwarf."

So what is a "free-floating" planetary body? An "interplanet"?

Samuel Webster (talk) 20:47, 24 July 2014 (UTC)

A "sub-brown dwarf", as mentioned in the article. Tbayboy (talk) 23:00, 24 July 2014 (UTC)

Ah, thanks, I see, it's lower down under "IAU". I still think it would be better to open with:

"An exoplanet or extrasolar planet is a planet that does not orbit Earth's Sun. Normally, exoplanets orbit ... but there are apparently rare cases of free-floating planets that do not orbit ..."

Something like that. But not a big deal.

Samuel Webster (talk) 11:49, 26 July 2014 (UTC)

NASA-TV (08/20/2014@5:30-6:30pm/et/usa) - Habitable Exoplanets.[edit]

FWIW - NASA-TV (08/20/2014@5:30-6:30pm/et/usa) - panel of experts discuss ancient Earth and Habitable Exoplanets< ref name="NASA-20140819">Brown, Dwayne (August 19, 2014). "MEDIA ADVISORY M14-137 - NASA to Air Panel Discussion about Ancient Earth and Habitable Planets". NASA. Retrieved August 20, 2014. </ref> - Enjoy! :) Drbogdan (talk) 13:52, 20 August 2014 (UTC)

FOLLOWUP - NASA VIDEO REPLAY - Excellent imo - Space Experts Discuss "Ancient Earth, Alien Earth" (59:38) at => - Enjoy! :) Drbogdan (talk) 23:51, 20 August 2014 (UTC)

Radio detection of exo moons[edit]

I believe that radio detection of exo-moons has been described as-in theory-possible(moons like Io). Should we add this to the article? --MyMoloboaccount (talk) 18:52, 20 August 2014 (UTC)