Talk:Phase angle (astronomy)

0 and 180 degrees
The value of 180 is the position when the object is between the illuminator and the observer, known as the astronomical opposition

That sounds wrong. Astronomical opposition is one case where the phase angle is 0. I think this should say The value of 180 is the position when the object is between the illuminator and the observer, known as the astronomical inferior conjunction --Albert White 14:22, 27 April 2006 (UTC)

I agree with Albert White. This is an egregious error and very misleading. The article also states "For some objects, such as Moon (see lunar phases), Venus and Mercury the phase angle (as seen from the Earth) covers the full 0–180° range." which is misleading. The constrained phases of Venus were first observed by Galileo, and he argued this supported the heliocentric solar system model of Copernicus. I recommend this article be deleted from Wikipedia. William.Forrest (talk) 16:27, 24 January 2015 (UTC)
 * 0° is theoretically possible in superior conjunction, although planets cannot be observed in such position. Incnis Mrsi (talk) 19:07, 3 April 2017 (UTC)


 * I've added 'inferior conjunction' to the article as suggested. Another point: What is said about backscattering and forward scattering may be technically correct, but I think it is unusual in an astronomical context and suggest it be removed from the article. I'm not sure the article itself should be removed as it at least gives the definition (which is why I found myself on the article page). --Brian Josephson (talk) 18:38, 11 February 2020 (UTC)
 * Actually the statement that 0 deg. corresponds to opposition is wrong as it could also be superior conjunction, so I've removed that part of the sentence from the article, which I'm beginning to think is pretty dubious (hope I've got that right as my head is beginning to spin). --Brian Josephson (talk) 18:51, 11 February 2020 (UTC)

Stub article
This article has a lack of formulae and diagrams to explain the derivation of the phase angle and its associated properties. So I would like to nominate it as a stub article in order to attract the attention of wikipedians who would be willing to improve it. — Preceding unsigned comment added by 146.90.21.236 (talk) 14:25, 27 April 2014 (UTC)