Talk:Earth/Archive 12

Archive 5

←

Archive 10

Archive 11

Archive 12

Archive 13

Archive 14

Archive 15

Water from comets

Currently, the article carries the following statement:

Condensing water vapor, augmented by ice and liquid water delivered by asteroids and the larger proto-planets, comets, and trans-Neptunian objects produced the oceans.

However, based on HDO isotope abundance measurements of Hale-Bopp, it looks like the idea that water was delivered to the Earth by comets is starting to come under question. See this news story.—RJH (talk) 22:41, 28 April 2010 (UTC)

I think the issue is that long-period comets probably didn't supply Earth's water. Main belt comets are now being considered as a possible source. Serendi^podous 07:06, 29 April 2010 (UTC)

Could be, but that is unclear from the news story. I couldn't find the Nature article mentioned.—RJH (talk) 18:02, 29 April 2010 (UTC)

Citations needed

I took the liberty of replicating this from a wikiproject discussion:

There are currently five figures in the "Orbital characteristics" part of Earth's infobox that are uncited. This shouldn't be the case on a Featured Article. If anyone could provide citations, that would very helpful. --Cybercobra (talk) 23:36, 24 April 2010 (UTC)

I agree with Cybercobra; we need cites for those values. The listed value for the semi-major axis is 1.0000001124; the PDF document on JPL's Keplerian elements page uses a value of 1.00000261 for the Earth-Moon barycenter. The eccentricity is also slightly different. If the aphelion/perihelion are computed from those, they may be slightly off.—RJH (talk) 15:55, 2 May 2010 (UTC)

Updated values of a and e based on cite. Anybody object to using computed values for aphelion and perihelion?—RJH (talk) 23:27, 3 May 2010 (UTC)

Edit request from 142.104.139.242, 20 May 2010

{{editsemiprotected}} Turn the word "world" in the first paragraph into an internal link.

142.104.139.242 (talk) 20:43, 20 May 2010 (UTC)

I'm not convinced that will help, Earth is known as "the world" not just world. Mikenorton (talk) 21:04, 20 May 2010 (UTC)

Not done: per Mikenorton. If you feel the link is really necessary, you are welcome to create an account. Regards, {{Sonia|talk|simple}} 22:57, 20 May 2010 (UTC)

I think that a lot of people will be coming here looking for the kind of content in the world article. 142.104.139.242 (talk) 23:30, 20 May 2010 (UTC)

I linked it again, see my edit summary. It had been linked for as long as I can remember and then less than a day after it is delinked we get this request. The definition of "world" can be ambiguous, I'm sure a lot of users will wonder what the Wikipedia article about "world" is actually about. LonelyMarble (talk) 02:52, 21 May 2010 (UTC)

Sorry for going against consensus on some words

Thanks to those of you who have patiently reverted my edit that went against prior consensus. I do intend to keep un-linking ordinary English words, but I'm glad to see you guys are willing to fix my inevitable mistakes. --Doradus (talk) 16:19, 21 May 2010 (UTC)

Thanks Doradus. I've done some cleanup of overlinking in the past, but there is undoubtedly more to be done.—RJH (talk) 19:05, 21 May 2010 (UTC)

The Origin of Earth (the article, not the planet)

First, someone mentioned above that the Earth article was "created." I think that it would be more accurate to say that the article evolved. Second, I think that the word "life" in the beginning of the article should be linked to the article on Life. —Preceding unsigned comment added by 138.9.57.31 (talk) 04:55, 22 April 2010 (UTC)

Natural selection doesn't really apply to data, unless Wikipedia has DNA and I just didn't know it. --Evice (talk) 22:25, 25 May 2010 (UTC)

Holistic views

A good article, but IMO misses to present a holistic view: just consider that there is no mention of ecology at all. There seems to be also a human-centric bias towards the end of the article: compare the lenght of the biosphere section vs. human geography + natural resources and land use + Cultural viewpoint --Elekhh (talk) 05:33, 22 April 2010 (UTC)

See WP:PSCI. --Evice (talk) 22:28, 25 May 2010 (UTC)

Sorry, misunderstood the term due to my tendency to associate the word with the pseudoscientific holistic medicine (science isn't my specialty except for technology). But anyway, this is an article written for humans by humans, so yeah, it's going to be human-centric, even if we aren't the only life forms on the planet. --Evice (talk) 22:34, 25 May 2010 (UTC)

SIZZE!

heard is the bigerst planet in the world, is true?

Well, it's the densest planet in the Solar System, and the largest terrestrial planet (which could make it the largest planet in the unlikely event that Jupiter, Saturn, Uranus and Neptune turn out to be sub-brown dwarfs), though not the largest that we know of. Serendi^podous 13:05, 24 April 2010 (UTC)

I'd be worried if it wasn't the biggest planet in the world, considering it is the world. Zazaban (talk) 23:09, 24 May 2010 (UTC)

You should mean biggest planet in the Universe or maybe in smaller poportions the Solar System, but not the World. Jhenderson777 (talk) 23:28, 24 May 2010 (UTC)

The Planet

This article should include that material from other planets could be broken up and added to ours instead of attempting to colonize other planets. Living further from the core of the planet would combat its higher gravity. EugeneKantarovich (talk) 01:36, 27 May 2010 (UTC)

Thanks for the suggestion, but I have a couple of concerns. Firstly, this really belongs in an article such as Geoengineering. Secondly, adding mass to the Earth would increase the gravity, which would be more than enough to compensate for the increase in radius. Mass increases as the cube of the radius (for the same density); gravity decreases as the square of the radius. A better application might be to boost the mass of Mars.—RJH (talk) 15:47, 27 May 2010 (UTC)

File:MODIS Map.jpg

Hi guys, I've just bringing your attention to this wonderful cloud cover map of Earth, in case you'd like to use it in the article, particularly in the Earth#Weather_and_climate section. NauticaShades 10:42, 4 June 2010 (UTC)

Circumference

The article has some very precise numbers for circumference: 40,075.02 km (equatorial), 40,007.86 km (meridional), 40,041.47 km (mean). I have not seen these elsewhere -- anyone know where the numbers are from? -- Radagast3 (talk) 23:54, 20 April 2010 (UTC)

Why are these measurements not given in miles? —Preceding unsigned comment added by 24.92.14.172 (talk) 04:54, 18 May 2010 (UTC)

Why would anyone use miles? Wikipedia is a global resource, not an American one. Metric measurements are the units of science, even in the USA. —Preceding unsigned comment added by 98.176.188.102 (talk) 16:48, 14 June 2010 (UTC)

The manual of style policy on units in scientific articles is described at Wikipedia:MoS#Which units to use and how to present them.—RJH (talk) 22:08, 14 June 2010 (UTC)

The "Life Cycle Of The Sun" image

Wouldn't a more appropriate title text for this image be "Life Cycle Of A Star", or maybe "Life Cycle Of A Sun"? The current title seems awfully geocentric. Sithman VIII !! 21:32, 26 June 2010 (UTC)

Unfortunately I have to disagree. That image is the life cycle of a Sun-like star; not a star in general. It only applies to a small set of all stars, and I don't see a need to confuse the issue for the reader. This article is about the Earth, so geocentricity is seems logical.—RJH (talk) 21:41, 26 June 2010 (UTC)

Automatically accepted

I am unclear how the new article "protection" scheme helps in the slightest when repeated edits by vandals like User:Dran0n get automatically accepted.—RJH (talk) 21:50, 26 June 2010 (UTC)

Dran0n is what we call a "sleeper account", created at 03:28, 4 August 2007 for precisely this reason. It became obvious it was a vandalism only account in November 2009, and the account should have been blocked at that time. Unfortunately, that wasn't done. The account recently returned again to vandalize, and by 21:35, 26 June 2010 it had reached the 10 edit, autoconfirmed threshold. Subsequent edits resulted in visible vandalism to this page. Viriditas (talk) 22:07, 26 June 2010 (UTC)

Thanks for the clarification.—RJH (talk) 22:08, 26 June 2010 (UTC)

Was this odd edit acceptance trial ever even mentioned on the watchlist or other place before it started? Maybe it's just me but Wikipedia regulars seem to be growing thinner and this isn't helping. LonelyMarble (talk) 02:53, 27 June 2010 (UTC)

Yes, it was, and it's been actively discussed for a long time. This is not something that just started out of the blue. You can visit WP:PENDING for more info. Viriditas (talk) 08:26, 27 June 2010 (UTC)

I know something like this has been discussed for awhile, I must have missed the message about the trial starting. Oh well, thanks. LonelyMarble (talk) 12:12, 27 June 2010 (UTC)

So... I am curious now as to why the history is becoming replete with reverts of anonymous edits. The reverts are being "automatically accepted", but the anonymous edits are just posted without comment. Is this tool even working? Thanks.—RJH (talk) 16:50, 30 June 2010 (UTC)

It just means that all the not accepted versions were never seen by the general public. −Woodstone (talk) 17:48, 30 June 2010 (UTC)

Sorry but it is still unclear. Does this mean that what is stated as a "revert" is actually a not-accepted edit?—RJH (talk) 18:54, 30 June 2010 (UTC)

No, a revert is still a revert, but the edit that was reverted was only ever seen by "reviewers" - casual readers (not logged in, or registered editors who aren't yet autoconfirmed) will not see the edit. They'll see the previous edit instead. TFOWR 20:01, 30 June 2010 (UTC)

Okay, thanks. I guess that means we'll see a lot more clutter in the article history then, which is a bit of a nuisance. Oh well.—RJH (talk) 21:18, 30 June 2010 (UTC)

adjectives

Seriously, the unmarked adjective for "pertaining to Earth" is terrestrial.

The other adjectives given -- earthly, tellurian, telluric, terran -- cannot be used in normal contexts. Since we must assume the adjectives are listed for people who are not aware of how to use them in the first place, you are doing them a disservice by listing the normal adjective last, after a bunch of eccentric vocabulary. "earthly" is for either ironic or for religious contexts; tellurian and telluric is for alchemy or similar baroque contexts; terran is for science fiction; chthonic is for mythology.

It's nice to have these adjectives in a thesaurus, say at wikt:terrestrial, but they do not belong in the infobox here. --dab (𒁳) 08:08, 28 June 2010 (UTC)

Agreed. Viriditas (talk) 09:50, 28 June 2010 (UTC)

Age of the Earth

The following story is regarding a revision to the estimated age of the Earth:

University of Cambridge. "Core values set new date for birth of the Earth". physorg.org. Omicron Technology Limited. Retrieved 2010-07-12.

They estimate it as 4.467 Gy.—RJH (talk) 17:05, 12 July 2010 (UTC)

Perhaps the lead should say "The planet began forming 4.54 billion years ago..."?—RJH (talk) 20:49, 12 July 2010 (UTC)

Fahrenheit

For the surface temperature in the table, maybe we should also add it in fahrenheit? It uses celsius and kelvin, which I know are used for scientific measurements, but I think that adding the values also in fahrenheit would make it more understandable for Americans. I have already converted them into fahrenheit:

Min: -128.9˚F Mean: 57.2˚F Max: 136.4˚F

If someone could please add these it would be great. —Preceding unsigned comment added by 69.245.201.211 (talk) 02:13, 15 July 2010 (UTC)

Template:Infobox Earth?

Has there been any thought about splitting the infobox into a separate template ({{Infobox Earth}}) as is done on the chemical element articles? It currently dominates the lede of the article when editing it. --Cybercobra (talk) 04:36, 25 July 2010 (UTC)

I brought this proposal up for discussion here: Wikipedia talk:WikiProject Astronomical objects#Infobox Planet sub-templates. Thanks.—RJH (talk) 18:38, 26 July 2010 (UTC)

Thanks. I don't think this is a good idea. It would fork the edit history and not improve the rendering speed of the article. It would reduce the size of the edit box, but the better idea (in my opinion) would be to figure out how to reduce the amount of material in the article by creating more targeted sub-articles. However, that's just my opinion. Single use infoboxes are routinely deleted at WP:TFD. Plastikspork _―Œ^(talk) 19:11, 28 July 2010 (UTC)

I think the infobox template could be shortened significantly just by deploying the notes and references to the reflists, per WP:LDR.—RJH (talk) 20:46, 29 July 2010 (UTC)

Good idea. We should try that first. Plastikspork _―Œ^(talk) 04:16, 30 July 2010 (UTC)

Earth mass

Earth mass updated data:

• Particle Data Group Review 2008 http://pdg.lbl.gov/2009/reviews/rpp2009-rev-astrophysical-constants.pdf

5.9722(6)× 10^24 kg

• The Astronomical Almanac for the year 2010 http://asa.usno.navy.mil/SecK/2010/Astronomical_Constants_2010.pdf

5·9721986 × 10^24 kg

Nasa factsheet seems to be outdated

Shcha (talk) 20:35, 1 August 2010 (UTC)

The original sources for the 5.9736 × 10²⁴ kg mass value date to 1995. Normally I'd be tempted to defer to the people who actually send satellites into Earth orbit, but it looks like the USNO almanac is referencing the JPL ephemeris. The odd thing is though, when I go to generate an ephemeris for the Earth on the JPL HORIZONS site, they show the 5.9736 value for the mass. So something doesn't seem quite right.—RJH (talk) 19:31, 2 August 2010 (UTC)

Surface temp in info box

Currently the minimum surface temperature is given as -89.4. I assume this is meant to be the minimum measured air temperature, recorded at Vostok Station, Antarctica, in which case I am fairly sure it should be -89.2. The -89.4 value comes from US sources that have converted -89.2 to °F, and rounded it off to -129°F, which, converted back to °C is -89.4. My primary source for this is a photo I've seen of the Vostok weather log book from July 1983, but to give some better refs, I found a WMO site, a site from the Arctic and Antarctic Research Institute in St. Petersburg (Google translated), and the Russian WP page about Vostok (Goggle translated). Therefore, I propose changing the minimum temperature to -89.2.

Another, possibly more reasonable option, would be to give less precise values. It could be simply rounding and giving -89 and +58 (the WMO site above gives +57.8), or dropping even another significant digit and giving -90 and +60, using the argument that we most likely haven't observed the real max and min, and our measurements have some uncertainty anyway. The parts of Antarctica that are higher than Vostok are colder, but there have not been any long-term stations there to observe a record minimum; presumably a similar argument could be made for the max.

A final issue is that these are actually air temperatures, measured 2 m above the surface, but the label is surface temperature. In Death Valley they claim to have measured surface temps near +93, and in Antarctica the surface can be several degrees colder than the 2-m air temperature, especially on the coldest days.

Given the multiple issues, I wanted to try to get some discussion before making any changes. I hope to hear others' thoughts. StephenHudson (talk) 22:51, 6 August 2010 (UTC)

78.09% nitrogen?

., the atmosphere is almost 80% nitrogen? it is a stat that i am suspicious of. is there somewhere or somehow we can confirm or deny the accuracy of this? or can point to specifics of nitrogen in atmosphere/terrestrial bio-cycles? 'nitrogen accumulates in the atmosphere, fills the following roles in Earth's water and ecosystems' ... otherwise this probably needs to be changed... —Preceding unsigned comment added by 131.230.224.28 (talk) 23:15, 6 August 2010 (UTC)

It's quite clearly stated in the referenced NASA document. So unless you think you know better than freaking NASA... (yes, CO2 and Oxygen being minority components is counterintuitive; but nonetheless correct). --Cybercobra (talk) 01:12, 7 August 2010 (UTC)

Absolutely agree with the number stated in the article. I have read the same numbers in a myriad of different sources. The Earth's atmosphere is about 78% Nitrogen, 21% Oxygen, and 1% other (and most of that other is Argon). Spinach Dip 09:52, 22 August 2010 (UTC)

In the Carboniferous, when atmospheric oxygen concentration was higher, insect respiration was effective enough to allow larger body sizes, such as Meganeura, the dragonfly with a wingspan as long as some human arms. __ Just plain Bill (talk) 16:31, 31 August 2010 (UTC)

Change image

Would be more appropriate if change image for the next animation: From Venezuela of Ronho Así y Asao (talk) 22:22, 24 August 2010 (UTC).

• Oppose—Sorry but it's not a natural image of the Earth and the animation is uneven. I prefer the current image. See also the FAQ at the top of this page.—RJH (talk) 19:19, 25 August 2010 (UTC)
  • Comment On this screen I see it at a low frame rate of about 10/s, but evenly so. Worth including, IMO, if not in the lead section. __ Just plain Bill (talk) 16:20, 31 August 2010 (UTC)
    • It's a 1.3 Mb file, which would slow down the download somewhat. I think there's a way to download it as a smaller, playable image, which would require a user click to trigger.—RJH (talk) 18:18, 31 August 2010 (UTC)

Life, again

Earth is the only place in the universe where life is known to exist.

I realize this gets brought up at least once a month, but this statement is so incredibly narrow and ignorant based on what we know today and what we can extrapolate in the future, I really can't see any good reason to continue to keep it in the lead section at this time. Across the board, astronomers are fairly certain that Earth-like planets are only 3-8 years, perhaps 10 at the most, away from being detected in extrasolar systems. The difficulty lies in detecting objects as small as the Earth, not in the assumption that they exist. Once they are detected, it will be another small step to detect signs of life in the atmosphere of these planets. I realize this is difficult for some people to understand or wrap their mind around but it is happening. Now, given what we know about the present and foreseeable future, if we are going to keep this statement in the lead section, there needs to be a hedge of some kind, indicating what we know now, in other words, that although Earth is the only place in the universe where life is known to exist at this time due to the limits of our current technology, scientists believe it is extremely likely that in the future, we will detect life in other places, either in our own solar system or on extrasolar planets. The statement as it currently reads, sounds like a reiteration of the archaic Ptolemaic view of the universe, an expression of a biased, anthropocentric perspective. We still like to think of ourselves as the center of the universe. Viriditas (talk) 11:36, 28 June 2010 (UTC)

I just put an {{as of}} in that sentence, hoping that will keep it clear without bulking up the lead with a lot of disclaimer-type circumlocution. __ Just plain Bill (talk) 11:45, 28 June 2010 (UTC)

That's a ridiculous objection. the statement is factually accurate. Regardless of the discovery of other planets, the fact is that Earth is indeed the only place in the universe where life is known to exist. --Dekker451 (talk) 05:27, 11 September 2010 (UTC)

Actually, we have already detected organic compounds on exoplanets, and detecting plant life is only around the corner. We would have already been able to do this with proposed projects like Terrestrial Planet Finder and New Worlds Mission, but as a species, we value war more than life, and we spend our collective money killing and destroying, rather than investigating and creating. I think it is very clear what is "ridiculous" here, and the statement is not factually accurate based on our best estimates of the future.[1] Viriditas (talk) 02:51, 17 September 2010 (UTC)

I completely understand your passion about this topic. However, "might detect" or "could detect" or "should detect" is still not the same thing as "have detected". You can speculate from here until eternity, but the statement "known to exist" is still true. There is already an article about extraterrestrial life. Please let's use that for the extended speculation. Thank you.—RJH (talk) 17:28, 17 September 2010 (UTC)

Regardless of whatever opinion of humanity you might have that doesn't change the fact that the statement is correct. Organic compounds are one thing but actual life is quite another. And anyway, as far as estimating the future is concerned, it's not the job of an encyclopedia to make predictions of the future. --Dekker451 (talk) 17:26, 19 September 2010 (UTC)

Whatever works. Viriditas (talk) 11:46, 28 June 2010 (UTC)

It's silly, but I guess that works for me; as long as we keep the speculation elsewhere.—RJH (talk) 16:51, 28 June 2010 (UTC)

Why do people never have a problem with this sentence in the lead: "Liquid water, necessary for all known life, is not known to exist on any other planet's surface." Shouldn't we add an {{as of}} tag or the word currently in that sentence as well? LonelyMarble (talk) 20:42, 28 June 2010 (UTC)

Yes, and to be consistent we should add an {{as of}} template to "It also is the only terrestrial planet with active plate tectonics" as well. :-) —RJH (talk) 23:25, 28 June 2010 (UTC)

Ha-ha-ha, I suppose to be consistent, you should add {{as of}} to almost every statement in any article... )

I'm sorry but I hope you realize that it says 'known' meaning, known to humans. Its not saying "The only place in the universe with life." but, "In the KNOWN universe." the unknown is still widely open to have life of course. Dobat 01:09, 28 July 2010 (UTC) —Preceding unsigned comment added by Dobat (talk • contribs)

No problem. This is covered by the FAQ at the top of the page.—RJH (talk) 14:49, 28 July 2010 (UTC)

Radius and circumference

I'm a bit surprised that this is an accepted source for the circumference (with an accuracy of 0.005km no less!) while there are other sources given for the radii and they do not seem to be in agreement with each other. Kalsermar (talk) 16:06, 21 September 2010 (UTC)

Well it would be great if a more definitive source for the circumference could be located. Thanks.—RJH (talk) 18:40, 22 September 2010 (UTC)

Text/link missing in mobile version

In Wikipedia mobile on my BlackBerry, the last sentence of the first paragraph ("It is sometimes referred to as the World, the Blue Planet, or by its Latin name, Terra.") is missing the word/link "Terra". I use Wikipedia mobile quite a bit and this is the first time I've seen this type of discrepancy. Since I'm unfamiliar with the conversion between standard WP content and the mobile interface, I'm unable to fix it myself. Any suggestions?

Thanks --GDW13 (talk) 20:58, 22 September 2010 (UTC)

Perhaps it's a layout or rendering problem with your device?—RJH (talk) 21:20, 23 September 2010 (UTC)

Factual Error

The article starts out stating that Earth is the fifth largest planet out of eight. It's actually the fourth largest out of eight. If you count Pluto it's the fifth largest out of nine. —Preceding unsigned comment added by 76.166.187.143 (talk) 17:47, 26 September 2010 (UTC)

Jupiter, Saturn, Uranus and Neptune are all bigger, by a considerable margin. This image shows sizes to scale (distances aren't to scale). TFOWR 17:56, 26 September 2010 (UTC)

Earth's magnetic field

Pardon me for saying so, but the line drawing in the Magnetic field section seems a little, well, vapid. It shows little more than a simplistic dipole magnetic field with none of the details of the Earth's magnetosphere. I'd like to suggest that we can find something a little more engaging. There are some okay images in the commons, but I see even better illustrations out on the web. Thoughts?—RJH (talk) 23:30, 30 July 2010 (UTC)

By way of comparison, here's an Encyclopedia Britannica illustration.—RJH (talk) 22:20, 30 August 2010 (UTC)

Here are some that might work:

• 
  Could use more labeling
• 
  Suggestions for improvement?
• 
  More interesting than the current one

I am willing to do some image massaging and conversion to SVG. Kindly point out the more inspiring ones you have seen on the web... __ Just plain Bill (talk) 01:37, 31 August 2010 (UTC)

Thanks. This ESA image looks pretty good, except for the oval and the words "trapping ssphere".—RJH (talk) 20:43, 27 September 2010 (UTC)

OK, work in progress. I just uploaded File:Magnetosphere blank base.jpg to use as a pattern for the SVG. This may take some time... __ Just plain Bill (talk) 01:38, 28 September 2010 (UTC)

Great. Thank you!—RJH (talk) 19:16, 28 September 2010 (UTC)

Life, regurgitated

Recently an editor added an entry to the first paragraph that I deemed off topic because it focused on extra-terrestrial planets and the possibility of extra-terrestrial life. I removed this as it appeared off topic for an article about the Earth and wasn't covered in the body. The author made claims about violation of WP:OWN, while I thought it a violation of WP:LEAD. Thus I'm bringing the discussion here in an attempt to reach consensus, and I'll present my views as an opinion below.

Regarding adding this type of information to the lead, or any mention of extraterrestrial life, we need to follow WP:LEAD. In particular, "The emphasis given to material in the lead should roughly reflect its importance to the topic". The closest we have to that is Habitability section. Somebody would need to expand on the information related to what makes an Earth-like planet habitable before that can be summarized in the lead. Presumably all such additions should be specifically relevant to the Earth in order to remain on topic.

Personally my preference would be just to include a link to extraterrestrial life somewhere in the lead, and keep the focus on the Earth. My opinion is that it should definitely not be the primary focus of the lead, most certainly not in the first paragraph, and should be a very minor aspect since the article is about the Earth. But that's just my position. To me, wandering away from a focus on the subject of the article starts to look like agenda pushing, which would be PoV-ish. Thanks. :-) —RJH (talk) 15:45, 1 October 2010 (UTC)

The article is currently pushing the rare Earth hypothesis in at least two different sections, yet makes no mention of the other POV in this regard. Why? Viriditas (talk) 20:38, 1 October 2010 (UTC)

Excellent point. They should be removed since they are more or less off topic, per WP:TOPIC.—RJH (talk) 20:41, 1 October 2010 (UTC)

Removed one. Viriditas (talk) 20:43, 1 October 2010 (UTC)

Article still says, "Liquid water, necessary for all known life, is not known to exist on any other planet's surface", yet is clarified by two footnotes, indicating that this needs to be brought in line with current findings. Viriditas (talk) 20:52, 1 October 2010 (UTC)

The sentence is in the present tense ("to exist" rather than "to have existed"); the comment about liquid being present on modern-day Mars needs confirmation before the sentence can be updated. The statement probably also needs some sort of proviso about being in a (somewhat) stable form, rather than the result of an impact melt. How about, "Liquid water, necessary for all known life, is not known to exist in equilibrium on any other planet's surface"?—RJH (talk) 21:18, 1 October 2010 (UTC)

I think the notes on Mars may need to be removed, per WP:TOPIC. It is possible that in the past there were a number of bodies in the Solar System that had liquid water, including Venus and possibly Ceres and elsewhere. But the sentence it is referencing is in the present tense. The other note is about a computer simulation only, and has little to do with Earth.—RJH (talk) 17:54, 3 October 2010 (UTC)

Good. I always felt a little dubious about that entry myself.—RJH (talk) 21:26, 1 October 2010 (UTC)

Mention of surface water in the lead

The lead contains the following sentence:

Liquid water, necessary for all known life, is not known to exist in equilibrium on any other planet's surface.

It has the following note attached:

Other planets in the Solar System are either too hot or too cold to support liquid water. However, it is confirmed to have existed on the surface of Mars in the past, and may still appear today. See:

• Malik, Tariq (2007-03-02). "Rover reveals Mars was once wet enough for life". Space.com (via MSNBC). Retrieved 2007-08-28.
• Staff (2005-11-07). "Simulations Show Liquid Water Could Exist on Mars". Daily Headlines. University of Arkansas. Retrieved 2007-08-08.

It is my belief that the two sources listed here do not satisfy WP:TOPIC and so should be removed. The first talks about Mars in the past, whereas the original sentence is about Earth in the present. The second is about a simulation, rather than an actual discovery of water on the surface of Mars. Neither contradicts the original sentence.

Does anybody have an issue with me removing the note? I'll wait a little while to see if there is a concern before proceeding. Thank you.—RJH (talk) 20:27, 10 October 2010 (UTC)

Doesn't bother me if you remove it. Serendi^podous 15:50, 22 October 2010 (UTC)

Note 6

I'd like to point out that Note 6:

"# ^ Blue Planet is used as the title of several films Blue Planet and The Blue Planet, in the Life issue The Incredible Year '68 featuring the Earthrise photo with lines from poet James Dickey Behold/The blue planet steeped in its dream/Of reality, and in the title of the European Space Agency bulletin report Exploring the water cycle of the 'Blue Planet'"

is grammatically incorrect, and as such reads quite badly.

I think it would read much better if it was changed to:

"# ^ Blue Planet is used as the title of at least two films (Blue Planet and The Blue Planet), in the Life issue The Incredible Year '68 which features the Earthrise photo and lines from Behold/The blue planet steeped in its dream/Of reality by poet James Dickey, and in the title of the European Space Agency bulletin report Exploring the water cycle of the 'Blue Planet'"

201.222.238.168 (talk) 03:40, 17 October 2010 (UTC)

 Fixed --Cybercobra (talk) 04:50, 17 October 2010 (UTC)

Works for me, thanks. I still think "The Blue Planet" is not a common name, so it's inclusion is dubious.—RJH (talk) 18:26, 18 October 2010 (UTC)

I'd say the same about Terra, but then this discussion has been had many times, and consensus seems to be to keep them. Serendi^podous 15:49, 22 October 2010 (UTC)

Mmm, Terra has a bit more of a legacy going for it. But no matter.—RJH (talk) 17:03, 22 October 2010 (UTC)