Talk:73P/Schwassmann–Wachmann

Pictures
I just wanted to let contributors know in advance that we should not go overboard with pictures. A nice one in the info box, and another one if someone catches a break-up in progress, that should suffice. Awolf002 21:19, 27 April 2006 (UTC)

Awolf, for comets and other transitory celestial phenomena, several pictures may be desired. This comet is of particular interest because it is in many pieces, and because of two extremely unusual conjunctions with showpiece objects M13 and M57. Robogun 17:05, 12 May 2006 (UTC)

Bright?
Okay, if this thing is so close, why the heck is it so dim, especially after breakin' into so many pieces? Other comets are bright! Jdos2 18:43, 4 May 2006 (UTC)
 * Schwassmann-Wachmann 3 was much brighter than usual when it started breaking up. Current pieces are small and that's why they're relatively dim even close to Earth.--Jyril 20:26, 4 May 2006 (UTC)

Impact nonsense
I'm not convinced we need that on the article albeit it has gained some publicity. Not without a mention how crazy theory it actually is (I've read Eric Julien based his predictions on crop circles).--Jyril 17:33, 5 May 2006 (UTC)


 * I think it should be mentioned, but make it clear how the theory is regarded by scientists. Yesterday I added an external link, and I think it is labeled as "crank" or "crackpot".  Bubba73 (talk), 18:39, 5 May 2006 (UTC)


 * Well, first of all, "crank" and "crackpot" are not suitable words for an encyclopedia. I'm not sure if this kind of ideas should be mentioned at all: True, there is a need to explain why such ideas are considered rubbish, but at the same time there's a danger that those ideas get too much publicity. And of course, there is a need for neutrality; I don't think that viewpoint is valid here. Wikipedia's main reason for existence is to spread free information, not misinformation.--Jyril 18:57, 5 May 2006 (UTC)


 * OK, no Crackpot or Crank (person). But I see your point, I'll change it.  Bubba73 (talk), 19:15, 5 May 2006 (UTC)


 * PS, it has been in the news lately, so I think it should be mentioned. Bubba73 (talk), 19:17, 5 May 2006 (UTC)
 * Please, give reference to reliable sources that this is notable enough to be included. Right now, we just have the self-published papers of the person and that is not enough. Awolf002 01:35, 6 May 2006 (UTC)


 * If you consider Yahoo News to be reliable:

Here. Bubba73 (talk), 01:46, 6 May 2006 (UTC)


 * Well, maybe Yahoo News isn't so reliable. ;-( Bubba73 (talk), 03:17, 6 May 2006 (UTC)


 * The Yahoo article is through the Newswire service, which isn't like the AP or Reuters written articles. If you pay for it, Newswire will stick your press release out there.  They don't care how reliable the content is or if it has any bias/agenda, just that you paid the fee.  If you look at the Newswire release page, you'll see what I meant.  Going back to the original comment, I think the whole section should be removed. Gogo Dodo 09:02, 6 May 2006 (UTC)


 * I think I must agree with Gogo Dodo. Both references hardly qualify for this section to be included. I will remove it, if there is nothing else that would make it a notable "factoid" about this comet. Awolf002 12:59, 6 May 2006 (UTC)


 * Yes, I later found out about the news feed and the sponsors, which is why I later commented that it may not be reliable. I only put in the external link (not the paragraph about it).  Nevertheless, I'm in favor of keeping it, but I won't object to its removal.  Bubba73 (talk), 14:34, 6 May 2006 (UTC)

Newly added text after passage of comet
I think the newly added section is way too much coverage for this hoax. I believe it was concluded above, that this speculation is hardly reaching notability enough to be included in this article. I would like to remove the whole section. Any problems with that? Awolf002 16:01, 29 May 2006 (UTC)


 * Support removal. If we mentioned everyone who had a doomsday theory about this comet (to say nothing of every other object that's made a close pass to Earth over the centuries), we'd never get around to the verifiable information. WP:NOT an indiscriminate collection of information. -- Filliam H Muffman 00:14, 30 May 2006 (UTC)


 * Not supporting removal: The hoax did result in a news event (Moroccan panic). If this page is meant to be strictly the scientific aspect of the comet, the information could be transferred to a new Comet Hoax page. Note the Comet Hale-Bopp article has a well-written subsection on comet related paranoia and superstition. Robogun 05:30, 31 May 2006 (UTC)


 * Your edit is a good compromise, Robogun. -- Filliam H Muffman 01:46, 2 June 2006 (UTC)

Orbital elements in flux
The orbital elements of 73P are changing slightly with the comet's proximity to the Sun and resultant loss of material due to its heating. The Horizons ephemeris at JPL gives a close approach on Sep 21, 2022 of 0.952749 AU with an uncertainty in position of of 564 and 394 arcsecs for RA and DEC respectively. The important factor is the 3D error ellipse which specifies the uncertainty in the position of the comet at that time. As the comet makes successive passes near the Sun the orbit is altered making predictions of the comet's "perigee" impossible to calculate over long periods of time.

73P's aphelion of 5.187 AU and perihelion of 0.9391 AU indicate that Jupiter and the Earth are perturbing bodies and close approaches to them can also alter the comet's orbit. 73P is one of the Jupiter family of comets. --Jbergquist 07:28, 15 May 2006 (UTC)
 * That is quite reasonable to comment on. However, note that the orbital elements are given at a certain epoch. At that time, those were the "official" values given by the Minor Planet Center. I would suggest, once the comet is further away from perturbation sources (read Earth and Sun) an update should be made with new values from the same source. Awolf002 23:42, 26 May 2006 (UTC)
 * That said, the main page gives two different values: 5.36 years and "slightly less than 5+1/3 years". Could somebody choose a good value and use it in both places? MathPerson (talk) 23:05, 5 September 2020 (UTC)
 * Done. Now using epoch 2017-Feb-16 -- Kheider (talk) 01:15, 6 September 2020 (UTC)

Not a hoax?
According to, this isn't a hoax. --Zeno McDohl 19:34, 27 May 2006 (UTC)

"Reality Check" Section
I have removed this section, since it was POV-pushing original research without citations. More importantly, a simple order-of-magnitude calculation shows that there is no significant probability of impact:

SW-3's orbit is ~10 AU long. Spreading the 2006 count of 66 large fragments along that orbit in a surface 0.08 AU wide (the width of dispersion needed to make an impact possible at all) gives a surface density of ~100 objects/AU^2. The Earth has a cross-sectional area of ~10^-8 AU^2. Therefore, on each orbit, there is roughly a 10^-6 chance of impact if the objects had dispersed that far. Since they have not, this is a massive overestimate and the probability of impact from the current fragments over the next century is order one in a ten million - much less than the impact probabilities of a few hundred other objects.

The true impact probability will be higher, because the fragments are continuing to break up. However, having more smaller objects is preferable to having a few large ones: they will evaporate faster and eventually be too small to make it through the atmosphere. As of 2006, the largest fragments were ~300 m across. After another few orbits, everything should have dissipated down to objects so small that they will only make meteors.

This estimate is very rough, but illustrates the point. For citation, I will quote the JPL Solar System Dynamics Group (ssd.jpl.nasa.gov). They have run the numbers as well as can be done, and quote a similarly low risk. Michaelbusch (talk) 14:23, 14 May 2010 (UTC)

CONTOUR spacecraft
I changed the section mentioning the planned visit by the CONTOUR probe, because it claimed the spacecraft was lost during launch. This is not true. Contact with the spacecraft was lost over a month after its successful launch into Earth orbit, during the firing of its integrated solid rocket motor. Jparenti (talk) 22:07, 18 June 2012 (UTC)