Talk:Mercury (planet)

Mercury's magnetic field

Hello, this is SpaceChimp1992. I'm one of the new users here at Wikipedia, and I created an article that I invested a lot of time into: Terraforming of Europa (moon). I am asking for your consent if it is O.K. if I create an article about Mercury's magnetic field. I'm also sure that it will be different than just re-stating what's already on Mercury (planet)#Magnetic field and magnetosphere, I will inform the reader about Mercury's magnetic field strength, magnetic field detection and magnetic poles, the discovery of this magnetic field, etc. Would that be okay? Cheers! --SpaceChimp1992 1:13, 15 July 2011 (UTC)

Possible Math Mistake in "Advance of Perihelion"

Quote from article:

"The perihelion precession of Mercury is 5600 arcseconds (1.5556°) per century relative to Earth, or 574.10±0.65 arcseconds per century[96] relative to the inertial ICFR. Newtonian mechanics, taking into account all the effects from the other planets, predicts a precession of 5557 arcseconds (1.5436°) per century.[96] In the early 20th century, Albert Einstein's general theory of relativity provided the explanation for the observed precession. The effect is small: just 42.98 arcseconds per century for Mercury"

Is there a mistake here, or has there been a new discovery in the past few years?

I remember hearing on a television special (History or Science or some such,) that the precession of Mercury is in fact not entirely explained by Relativity, and that there is still an unknown influence on Mercury causing it to precess. This detail is not mentioned in this section of this article, though it definitely should be.

Also suggest mention and references of how alternate calculations were done before relativity. It helps to know what "wrong" or "insufficient" calculation have been tried in the past.

In other words, why isn't the best previous Newtonian calculation actually shown, and then actually show the best Relativity calculation.

This is relevant, because I have discovered...an anomaly...and want to mention it in a paper.

WadeDanielSmith (talk) 00:11, 2 November 2015 (UTC)

Information this detailed is probably better suited for Tests_of_general_relativity#Perihelion_precession_of_Mercury. A2soup (talk) 02:13, 25 December 2015 (UTC)

File:Mercury in color - Prockter07-edit1.jpg to appear as POTD

Hello! This is a note to let the editors of this article know that File:Mercury in color - Prockter07-edit1.jpg will be appearing as picture of the day on January 13, 2016. You can view and edit the POTD blurb at Template:POTD/2016-01-13. If this article needs any attention or maintenance, it would be preferable if that could be done before its appearance on the Main Page. Thanks! — Chris Woodrich (talk) 01:09, 25 December 2015 (UTC)

Picture of the day

Mercury is the smallest and closest to the Sun of the eight planets in the Solar System. It has no known natural satellites. The planet is named after the Roman deity Mercury, the messenger to the gods.Photograph: NASA/APL/CIS; edit: Jjron

Mercury's atmosphere

http://nssdc.gsfc.nasa.gov/planetary/factsheet/mercuryfact.html <~5 x 10-15 bar

I've added the info to the article where appropriate. Thanks for the suggestion! A2soup (talk) 16:12, 27 January 2016 (UTC)

Tidally locked or not

I'm new to this whole "edit" process, but I noticed a problem. It says Mercury is gravitationally locked. It should say that it is NOT gravitationally locked. Or better yet, tidally locked. Thanks. TDFmachine (talk) 14:45, 7 February 2016 (UTC)

Indeed, it's only 3:2 locked. See

References

I made the change ([1]) in the article, and added the source. I also made a wp:wikilink to article Tidal locking. Good find. - DVdm (talk) 15:07, 7 February 2016 (UTC)

OK, So, I understand the cited book says [3:2] "resonance", but I can't figure out why this should be a Resonance; what seems to actually happen, if you watch Mercury from the Sun, is that Mercury's rotation follows the Sun **near perihelion** (very near Perihelion rotation actually lags behind orbit); far from perihelion, the tidal stress tends to slow Mercury's rotation, but near perihelion the tidal stress is about three times greater. The apparent ratio [3:2] isn't necessarily an integer ratio at all, but something that should be calculated from Mercury's eccentricity. NOW, whether one can **put that in the article**... one would have to hunt up an actual source. In any case, the cited work doesn't actually establish the claim. Jcmckeown (talk) 05:59, 9 March 2016 (UTC)

Near perihelion, when the tides are largest, they are almost stationary on Mercury, so they don't significantly slow down or speed up its rotation. As you say, this would be only an approximate situation, which would not lead to a precise 3:2 ratio. However, here is another factor. Even without tides, Mercury is not exactly spherical. It has a permanent bulge on one side. The rotation is such that at perihelion this bulge faces toward or away from the Sun. This couples to the tidal component of the Sun's gravity, which keeps this situation permanent. This locks the rotation of the planet to an exact 3:2 ratio with its orbital motion. DOwenWilliams (talk) 15:04, 9 March 2016 (UTC)

Requested move 7 April 2016

Mercury (planet) → Mercury – This is a level-3 vital article, while the element is a level-4 vital article. Thus, this should take precedence. Sir Cumference π 19:01, 7 April 2016 (UTC)

• Oppose. That's not how determining primary topics works. I could elaborate, but as I don't expect this will get much traction, I'll just leave it at this for now. Egsan Bacon (talk) 19:30, 7 April 2016 (UTC)
• Support. The levels have nothing to do with it. But the planet is currently 50.3 percent of pageviews (499,133/991,696). See here. Brother Twisted (talk) 03:39, 8 April 2016 (UTC)