Talk:Venus

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Featured article Venus is a featured article; it (or a previous version of it) has been identified as one of the best articles produced by the Wikipedia community. Even so, if you can update or improve it, please do so.
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Hellish Atmosphere and Electric Winds[edit]

Recent Discoveries regarding Venus Atmosphere indicate that a powerful electric wind stripped all water from the planet by breaking down water molecules into hydrogen and oxygen atoms.

"Add this to the list of reasons Venus is a blistering hellscape: not only is the surface hot enough to melt lead, not only will the sulfuric acid rainstorms burn gaping holes in your partially-melted spaceship, it’s got a monstrous electric wind that appears to have helped strip all the water out of the atmosphere. Good luck gardening in your cloud city. Scientists have long suspected that all planets with an atmosphere also have an electric field, generated by a layer of charged particles in the upper atmosphere called the ionosphere. But so far, on every planet where we’ve looked, including our own, we’ve been unable to detect it. The working theory is that these electric fields are very, very weak—Earth’s is thought to be in the range of one to two volts. Venus is different. “Venus’ electric field is enormous—it’s a monster lurking in the sky,” said Glyn Collinson, lead author on a study published today in Geophysical Research Letters which used data collected by the ESA’s Venus Express mission to measure that electric field for the very first time.[1]

I suspect this articles Bond albedo to be wrong[edit]

The paper source for Bond Albedo does calculate the Albedo only for a specific visual wavelength band to be 0.9. However, the General Bond Albedo should be given for the full solar spectrum. The wrong Bond albedo in this article leads to consistently wrong calculations of Venus' radiation equilibrium temperature elsewhere in wikipedia and the web, because Albedo in such calculations is very crucial. This NASA fact sheet http://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html states 0.77 for Venus' Bond Albedo. I agree that there could be better citable sources, however just check the source given at the moment and you will find that only a relatively narrow-band Bond albedo is described in the source. --129.13.156.135 (talk) 13:09, 10 January 2017 (UTC)

I have found this source: "Spectroscopy of planetary atmospheres in our Galaxy", authors: Giovanna Tinetti, Thérèse Encrenaz & Athena Coustenis, stating 0.8 for Venus' albedo (NASA: 0.77). --129.13.156.135 (talk) 15:39, 24 January 2017 (UTC)
I have changed the value as noted in the edit request section below. Thanks so much for spotting this! You have probably noticed that the infobox also cites a "geometric albedo" from the same paper that game the narrow-band Bond albedo. I don't know how geometric albedo differs from Bond albedo, but is that value accurate or also only for a specific wavelength? A2soup (talk) 20:57, 24 January 2017 (UTC)
Actually, never mind. The NASA fact sheet also gives a geometric albedo - I will just change it to that value. A2soup (talk) 21:01, 24 January 2017 (UTC)
Regarding Venus Bond, spherical and geometric albedo there seem to be differing values for identical albedo types (e.g. "geometric") in the literature, so that I am really confused now. And NASA has been definitely changing its fact sheet over time. I hope - as best available experts - they are correct now. --129.13.156.135 (talk) 10:49, 25 January 2017 (UTC)
I hope so too. As they are a reliable secondary source, they are preferred over any specific albedo reports in the primary literature. A2soup (talk) 17:48, 25 January 2017 (UTC)
Thank you very much for editing and co-deciding A2soup! Best regards --129.13.156.135 (talk) 11:18, 26 January 2017 (UTC)

Semi-protected edit request on 24 January 2017[edit]

Venus' Bond albedo value should be changed to either 0.77 or 0.8, compare discussion section. 129.13.156.135 (talk) 15:42, 24 January 2017 (UTC)

 Done I have changed it to the NASA fact sheet value, as secondary sources are preferred and the value is more precise. Great job spotting the error!! A2soup (talk) 20:54, 24 January 2017 (UTC)

Rotation phrasing[edit]

Venus's rotation has slowed down by 6.5 min per Venusian sidereal day in the 16 years between the Magellan spacecraft and Venus Express visits.[98]

Venus's rotation has slowed down in the 16 years between the Magellan spacecraft and Venus Express visits, making the Venusian sidereal day 6.5 minutes longer.[98]

Original sentence is poorly written, is Venus's sidereal day 6.5 minutes or 2.6 hours slower today? Reference states 6.5 minutes but some napkin math based on that 'per' clause could lead someone to believe otherwise. — Preceding unsigned comment added by 192.109.145.48 (talk) 07:05, 30 March 2017 (UTC)

I've change the wording in the article per this request, though slightly modified. I wasn't quite satisfied with using the word "making" in the article. Let me know if there's any further changes needed. Huntster (t @ c) 21:52, 18 April 2017 (UTC)

Earth Venus Pentagram is Heliocentric[edit]

In the image on the right side it says:

The pentagram of Venus. Earth is positioned at the centre of the diagram, and the curve represents the direction and distance of Venus as a function of time.

This is incorrect. The Sun is positioned at the centre of the diagram. To understand why, see this animation. — Preceding unsigned comment added by Metasintactic (talkcontribs) 05:45, 18 April 2017 (UTC)

Metasintactic, here's the thing: the image can represent *both* a Geocentric and Heliocentric view (and, I believe, it works in a Cytherocentric model as well). It's kind of nifty like that. Your video shows the Heliocentric view, but the citation at https://johncarlosbaez.wordpress.com/2014/01/04/the-pentagram-of-venus/ shows the Geocentric view. The question is which description better serves our readers so they understand what's going on. So, here's the two captions together:
  • Original, Geocentric: The pentagram of Venus. Earth is positioned at the centre of the diagram, and the curve represents the direction and distance of Venus as a function of time.
  • Proposed, Heliocentric: The pentagram of Venus. This diagram represents the direction and distance between Venus and Earth as they orbit the Sun. Each point shows the center of motion between the two planets.
So, which provides the better educational and comprehensive value? Huntster (t @ c) 22:42, 18 April 2017 (UTC)
Huntster, my feeling is that the heliocentric model is more clear because using a geocentric model implies that venus is orbiting the earth, which clearly it does not. The video animation I provided clearly illustrates the motion that's depicted in this image. I have seen various written claims that it works geocentrically, but I've not seen any illustration or animation which explains how this geometry is arrived at from that perspective. I wouldn't have brought it up were it otherwise. Metasintactic (t @ c) 10:47, 6 May 2017 (UTC)
Metasintactic, I have no problem using a Heliocentric model, but we have to find an image or animation that is freely licensed. But as to the different models, it doesn't matter which you choose, they'll all show the same orbital paths. Huntster (t @ c) 17:26, 6 May 2017 (UTC)
Huntster, I don't see there's any problem sticking with the existing image. All that needs to change is the text underneath. Also, though I realise wikipedia tends to frown on using external links, this is one case where I feel the link to the youtube video above would provide an invaluable context to help people understand precisely what's depicted. I'd appreciate your thoughts on that also. Metasintactic (t @ c) 07:03, 8 May 2017 (UTC)

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