Talk:Opposition surge

Merger

The two terms are quite clearly describing the same thing. Although this is the newer article, I'd suggest moving to this title for three reasons: 1) this is the larger article; 2) Google gives twice as many hits for "opposition surge" than it gives for "opposition effect" - take out those pages which mention both terms and the count is 41k to 17k in favour of "opposition surge", a ratio of 2.5:1; 3) it seems to be the term used by the likes of NASA, Encyclopedia Britannica, and ESA. Furthermore, if this article is anything to go by, the "surge" is composed of two separate "effects", and as such, for the sake of clarity this may be the more appropriate title. Grutness...wha? 10:51, 19 May 2009 (UTC)[reply]

I agree with the above poster and support merging into this article. All of the literature I've seen recently on the subject refers to the effect as the opposition surge.Sailsbystars (talk) 01:14, 26 July 2010 (UTC)[reply]

The article "Opposition surge" is definitely better, because the "Opposition effect" article does not mention the coherent backscattering phenomena as the (other) cause of the effect. However, the coherent backscattering is widely accepted theory among people studying light scattering and new publications on the subject appear regularly on scientific journals. 128.214.14.85 (talk) 13:13, 13 December 2010 (UTC)[reply]

A year and a half and the few comments here have been supportive - I'll see what I can do about a merger. Grutness...wha? 23:25, 13 December 2010 (UTC)[reply]

Yeah, it's not a terrible well-trafficked article, since its not particularly well known even in the planetary science community, so I would count the three votes here as overwhelming consensues :). Looks like a decent merge to me. Some day in my <sarcasm> copious free time </sarcasm>, I'll try to expand on the coherent backscatter bit that I added. Sailsbystars (talk) 23:55, 13 December 2010 (UTC)[reply]

Thanks - though I'm a fairly keen amateur astronomer most of my knowledge of opposition surge is through my MSc work in visual perception (contrast effects were a major part of my study), so hopefully I haven't made any inadvertent mistakes in the transfer. Grutness...wha? 00:31, 14 December 2010 (UTC)[reply]

Improvement

Diagrammes

Both physical mechanisms could do with a diagramme to help with the explanation. —DIV (138.194.11.244 (talk) 06:51, 27 July 2011 (UTC))[reply]

yeah that occured to me as well. I'm planning on updating the article over the next momth or so, as I'm currently reading through Hake's book on emittance and reflectance spectroscopy for work...... Sailsbystars (talk) 11:32, 27 July 2011 (UTC)[reply]

Article seems to contradict itself

The "Physical mechanisms: shadow hiding" section talks about the opposition surge of the rings of Saturn, and says that the shadow hiding mechanism "was first proposed by Hugo von Seeliger in 1887."

The "Opposition surge throughout the Solar System" section says that "The existence of the opposition surge was first recorded in 1956 by Tom Gehrels during his study of the reflected light from an asteroid."

These two statements conflict as written; if someone proposed an explanation for an opposition surge in 1887, it was clearly observed at that time, before 1956. Possibly the scope of the second statement can and should be narrowed in such a way that it doesn't conflict with the first statement, but I don't have the background to disentangle it. Steorra (talk) 14:11, 15 June 2013 (UTC)[reply]

Indeed, that is contradictory and I don't have a good resolution. Perhaps first detection on an asteroid? Further, knowledge of the opposition surge actually predates both of those. My google fu is failing me, but in a recent talk on coherent backscatter someone referenced a renaissance monk who documented the existence of the effect(although not the explanation) by noting that he had the halo and no one else did. Sailsbystars (talk) 15:50, 15 June 2013 (UTC)[reply]

No such surge has been reported for gas giant

Clearly there is a surge for Saturn and the last reference in the article as of the date of this post documents it. Jplvnv (talk) 19:42, 5 December 2013 (UTC)[reply]

Not from the planet Saturn, but rather from its rings. Rings!=gas!=a gas giant planet. Sailsbystars (talk)

Should it be merged with Heiligenschein?

It seems this and Heiligenschein are talking about the same phenomenon; perhaps the two should be merged? --TiagoTiago (talk) 21:26, 21 May 2015 (UTC)[reply]

I was wondering the same thing. Both articles use the same exact photograph of the lunar landing, and each explains a different cause of the lightened area. Either one of them is wrong, or BOTH are true. If both are true, however, then why doesn't it mention Heiligenschein or link to the article anywhere on this page? Either "Heiligenschein" is caused by "opposition surge", and the pages should be modified and/or merged together, or one of the two article captions is wrong, and should be changed..45Colt 16:49, 17 October 2015 (UTC)[reply]

It seemed to be the case that Heiligenschein is about the dewdrop mechanism and Opposition surge is about the astronomically-relevant mechanisms. That seems pretty reasonable to me, and I edited both articles to make that clearer. --Steve (talk) 17:21, 2 April 2019 (UTC)[reply]

Influence on discoveries

Some of the bias in the location of discovered objects is likely because many observations are done from the ground, and it's hard to see asteroids during the day. Not changing the article because "original research" and I don't have a source for this reasoning. 23.121.191.18 (talk) 12:45, 27 April 2019 (UTC)[reply]

Terrestrial equivalents

Is this at all related to seeing a "halo" around ones shadow, when looking down into (low clarity) ocean water with direct sunlight behind? Neftaly (talk) 05:58, 12 June 2019 (UTC)[reply]

The opposition surge is due to single event scattering

The opposition effect is due to single event scattering, where the scattered radiation is coherent because all the scattering dipoles are directly stimulated by the illuminating radiation.
The Scattered light is considered in the literature as a diffusive light, light that passed a number of scattering events before it left the scattering material. Diffusely scattered light must obey Lambert's Cosine scattering law. In the case of unidirectional light scattered backward from a surface of a sphere, the meaning is maximum scattering intensity in the middle of the sphere surface, and a decline to zero toward the periphery by the cosine law.
The full moon looks uniform and people continue to assume that the light is diffusely scattered from it.
More than that. The nearly uniform sphere image is common to all the planets and their moons, including the earth as observed from the moon. Out of thousands upon thousands of true photos, there is no single true photo that obeys Lambert's Cosine law. The only photos that do obey the law are rendered photos, photos that are at least partly simulated.
Contrary to all that, if the scattering is assumed to be mainly a single event, then all the scattering dipoles are directly stimulated by the light radiation on the illuminated scattering material. Then scattering by them must be coherent, and then the full moon and all the other illuminated bodies, with similar illumination geometry, must be uniform, at least approximately. The full moon tells us that single event scattering is dominant. Maybe with small corrections of multiple scattering.
Why is the single event dominant? It seems that the effect is geometrical and statistical. If we consider one event scattering, two event scattering, multiple event scattering, then the event probability will decline with an increasing number of scatterings. The single event has a probability of at least 50% and it is the strongest event.
Nearly all the background landscape that surrounds us is a singly scattered light. A true diffusely scattered light is rather rare.

Urila (talk) 08:57, 14 May 2020 (UTC)[reply]

Original Research

The image at the bottom contains original research. — Preceding unsigned comment added by 2600:8806:A100:73:B56A:3B49:B826:67D6 (talk) 05:32, 17 March 2021 (UTC)[reply]

Main reason: Scattering from particles around 10 um

In this article, the main reason for the effect is omitted. Particles larger thane the wavelength of the light lead to scattering which depends strong form the angle of view. The reason is, taht all molecules in the particles are dipol senders, and their radiation interferes. The book Bohren/Huffmann Absorption and scattering of light by small particles gives a good explanation for this. And it contains a program for calculating the effect. I have this program running. I chnged the German version of the artice. But I am not a natural English speaker, so I don't change this version. But I give support, if somebody starts editing. Beside this, here is a mistake: Coherent scattering is the one of illumination with coherent light (LASER). See n Lenke/Marek (2000): Multiple Scattering of light: Coherent backscattering and transmission. I recommend deleting this section. — Preceding unsigned comment added by Uwe Pilz, Leipzig (talk • contribs) 06:00, 12 January 2023 (UTC)[reply]