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This is an old revision of this page, as edited by 24.235.198.91 (talk) at 23:25, 2 January 2010 (→Some minor details in the naming section). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Russian plans

This article just popped up this morning. Anyone interested in editing this article may find it interesting and may be able to incorporate the information. http://news.yahoo.com/s/ap/eu_russia_asteroid_encounter 98.215.128.112 (talk) 17:55, 30 December 2009 (UTC)[reply]


My apologies. Apparently someone has already found and posted the article below. 98.215.128.112 (talk) 17:57, 30 December 2009 (UTC)[reply]

Somebody should add this to the article. http://news.yahoo.com/s/ap/20091230/ap_on_re_eu/eu_russia_asteroid_encounter I don't know how and don't want to mess it up. —Preceding unsigned comment added by 67.175.127.171 (talk) 15:35, 30 December 2009 (UTC)[reply]

Perminov's statements (in the linked interview) indicate that he was not aware of the low probability of impact, and do not reflect any official decisions by Roscomos - so there aren't really any 'Russian plans' yet. I recommend that we leave this out of the article for the moment. Also please remember that this is the talk page for editing the article about Apophis, not a forum for personal opinions (I removed those posts). Michaelbusch (talk) 19:20, 30 December 2009 (UTC)[reply]

I agree and have added it. The news story does not talk about Russian Plans, it merely talks about a statement to look into a possible mission, i.e. it may make plans and is considering that now. This is very relevant and worth reporting, as it comes from the official Russian Space Agency. Its not up to us to interpret that they "are not aware of the low probability." That is not relevant.76.14.42.191 (talk) 20:31, 30 December 2009 (UTC)[reply]

Since you insist, 76.14.42.191, I'll let it stay. But I have rephrased the text to be more accurate. Note: I do have a personal bias with this article. I am a member of the team that has been refining the impact probability estimates for the past several years. It is very relevant to me that Perminov has apparently been mis-informed about our work. Michaelbusch (talk) 20:39, 30 December 2009 (UTC)[reply]

My 2 cents. -- Kheider (talk) 20:54, 30 December 2009 (UTC)[reply]


Thanks for letting it stay and I have no problem with your re-wording of my addition. I can see you are close to the subject, and you are probably right that Perminov has been mis-informed about your work. However, we as editors here need to be careful to merely report and not interject our bias, even if that bias is well informed on the subject. Perhaps Perminov is aware of the probabilities but doesnt want to take any chances, or perhaps its PR reasons that they are talking about this. Lets wait to see if other respected and notable people speak about this latest development, but lets not fail to report on it.76.14.42.191 (talk) 20:56, 30 December 2009 (UTC)[reply]
Even if the impact is not very likely, this mission could make a lot of sense. This asteroid would offer a perfect opportunity to practice deflecting a body headed for Earth, so if in a few decades or centuries another body appears that will actually hit Earth, invaluable experience gained during the practice mission will make deflecting it that much easier and cheaper. In other words, since we practice responding to disasters all the time, we could do so here as well. Sourcelat0r (talk) 23:04, 30 December 2009 (UTC)[reply]

2013 Pass of Apophis

Novosti 2009-02-25 (http://en.rian.ru/analysis/20090225/120298367.html) says "In 2012, Apophis will pass close enough to Earth, enabling scientists to more accurately calculate its 2029 orbit." If so, ISTM worth giving date and distance of that pass, and of any other comparatively near passes before the important ones. 82.163.24.100 (talk) 18:59, 25 February 2009 (UTC)[reply]

See Talk:99942_Apophis/Archive_2#2016_Venus_encounter for more details.. -- Kheider (talk) 19:24, 25 February 2009 (UTC)[reply]

Some minor details in the naming section

The statement of Apophis being the most persistent Stargate villain, although in the article Goa'uld characters in Stargate is stated that Ba'al is the longest-running villain in Stargate show. 195.39.74.163 (talk) 17:21, 13 July 2009 (UTC)[reply]

The article cites a supporting source. Because of this, the article should be read as asserting that

Although the Greek name for the Egyptian god may be appropriate, Tholen and Tucker — two of the co-discovers of the asteroid — are reportedly fans of the TV series Stargate SG-1. The show's most persistent villain is an alien also named for the Egyptian god." (Supporting source: Bill Cooke (August 18, 2005). "Asteroid Apophis set for a makeover". Astronomy Magazine. {{cite journal}}: Unknown parameter |urldate= ignored (help).)

As that cited supporting source does indeed support the assertion, the article should not be changed to make a contrary assertion; though information about contrary assertions made by other sources (with those sources being cited, of course) might be added to the article. Or, alternatively, perhaps this bit of trivia might be left out of the article. See WP:V, WP:CITE. Wtmitchell (talk) (earlier Boracay Bill) 23:38, 14 July 2009 (UTC)[reply]
Could be that at the time of the discovery, The show was still in production. Stargate SG1 ran 10 seasons, and Apophis was a major antagonist for at least the first 4 (possibly 5 or more), while Baal (spelling?) was introduced later on (5th season perhaps?) 24.235.198.91 (talk) 23:25, 2 January 2010 (UTC)[reply]

Aldrin Manned Mission Plan

During the lecture for the 40th Apollo 11 Anniversary, Buzz Aldrin proposed a manned mission, here's a powerpoint slide of his which shows it, if someone wants to add something to the missions section: http://www.nasawatch.com/archives/2009/07/buzz_aldrins_on.html —Preceding unsigned comment added by Jafafa Hots (talk • contribs) 10:43, 20 July 2009 (UTC)[reply]

Which is it?

"Apophis’s brightness will peak at magnitude 3.3, with a maximum angular speed of 42° per hour. The maximum apparent angular diameter will be ~2 arcseconds, so that it will be barely resolved by telescopes not equipped with adaptive optics."

"On that date, it will become as bright as magnitude 3.3 (visible to the naked eye from rural and some darker suburban areas, visible with binoculars from most locations"

According to the Apparent_magnitude page, the second quote would appear to be the correct one. Does someone want to take a shot at fixing this? —Preceding unsigned comment added by 76.21.3.245 (talk) 12:53, 14 August 2009 (UTC)[reply]

The resolving power of a telescope has nothing to do with the limiting apparent magnitude. These are separate characteristics. It is the difference between seeing an object (magnitude) and resolving it as a disc. -- Kheider (talk) 15:08, 14 August 2009 (UTC)[reply]

1 in 233,000 chance

I rv'ed an edit showing a 1 in 250,000 chance of a collision. The auto generated link at NEO does show the odds as only 1 in 233,000 (2036-04-13.37; 4.3e-06), but since it is an auto generated page I think it is better if we stay with a human created reference. Besides there have been no new observations of the asteroid since 2008-01-09. -- Kheider (talk) 18:31, 7 October 2009 (UTC)[reply]

As per an October 7, 2009 NASA Release, chances of impact in 2036 have been recalculated to be 1 in 250,000. So, I undid your edit and added the reference. Darry2385 (talk) 19:04, 7 October 2009 (UTC)[reply]
Ah good. Nice to know the automated program is accurate. :) -- Kheider (talk) 19:28, 7 October 2009 (UTC)[reply]

Easter Sunday

The event of 2036 will occur on Gregorian Easter Sunday (Orthodox Easter Sunday will be a week later) - that seems worth mentioning.

Could there be a table of all nearest approaches this century, with brief details including miss distance, visible magnitude, GMT of pass, terrestrial nadir of pass, with uncertainties?

82.163.24.100 (talk) 09:57, 8 October 2009 (UTC)[reply]

NEODyS Close Approaches (ref #13) has the info you are looking for. -- Kheider (talk) 10:11, 8 October 2009 (UTC)[reply]

Impact risk path

Path of risk where 99942 Apophis may impact Earth in 2036.

I have a question. According to the impact risk there is a path that covers a 20 hour earth turn rate. (I would think the curved path indicates this is a time lag due to how the earth is turned).

At the speed the earth is revolving around the sun how can predictions of the accuracy they are claiming be made? Just wondering. —Preceding unsigned comment added by 207.160.238.250 (talk) 16:08, 21 December 2009 (UTC)[reply]

Using Newtonian mechanics, the errors in the known trajectory of Apophis result in slightly different arrival times and impact points. If we knew the exact orbit of Apophis we would know when and where it would hit. When Apophis gets very close to the Earth there will be significant perturbations to the asteroid. -- Kheider (talk) 21:45, 21 December 2009 (UTC)[reply]
This seems to be based on this,particularly this and this cited there. Wtmitchell (talk) (earlier Boracay Bill) 01:18, 1 January 2010 (UTC)[reply]
It should be noted that this path prediction for a 2036 impact is based upon calculations with an estimated mass from a theoretical model which cannot be accurate without a much better understanding of the exact metalurlgical and geological make-up of Apophis. Further, the 2029 path may well lead to a gravitational deflection, and/or an increase or decrease in velocity, which cannot be accurately calculated without knowing the specific mass of Apophis, and which may completely alter the illustrated path and/or time of the 2036 encounter. I fail to see how this illustration holds any relevence whatsoever. There cannot be any significant degree of certainty until after 2029. The distance Apophis travels means that even slightest error in estimation could convert to a huge change in predicted orbital path.
There are predictions for both 2036 amd 2037 (for an estimated 7 year orbit?). The 2029 orbit is theorized to pass close to a "keyhole" with a 2000ft diameter, Apophis is estimated at 1300ft in diameter, the 2006 prediction has a 2000 mile margin of error...and has anyone considered loss of mass due to outgassing and such? More estimates equal greater margins of error, regardless of scientific method or the theories applied. There is any given number of stellar bodies along the Apophis orbit which could introduce variables that could never be predicted without actually trailing Apophis through it's entire orbit.
There is no need to label this illustration as the prediction for a "Path of Risk" for a period of 20 hours on October 13, 2036, alarming people who may be near to this path for nothing... The illustration does however reflect the possible path of a non-geostationary sattelite traveling counter to the earth's rotation, and is an excellent example of exactly that. Wikipedia is not a soapbox for those looking to justify or finance a trip to space. 24.235.198.91 (talk) 22:10, 2 January 2010 (UTC)[reply]

Risk path, 2036 or 2037?

This image is used on both elsewhere on this talk page and on the main article, as well as on a few other articles. The filename File:2037 Apophis Path of Risk.jpg indicates that it charts the path of risk in 2037, but the descripion always cites 2036. As 2036 is the greater risk, it seems likely that the file was misnamed. Can anyone confirm the correct year for this image and correct its name or usage? —Preceding unsigned comment added by Sparr (talk • contribs) 05:00, 31 December 2009 (UTC)[reply]

It is certainly meant to represent the 2036 keyhole risk (NEO at JPL). -- Kheider (talk) 05:41, 31 December 2009 (UTC)[reply]

Impact calculations: solid rock vs. rubble pile

I was wondering how the impact calculations would differ if the asteroid Apophis turns out to be a big rubble pile, its center of mass would change during close approach and rotation rate? Also if Apophis turns out to be a rubble pile that breaks apart on close aproach to Earth,How much more of a threat would it be to multible geostationary satellites? Jalanp2 (talk) 18:26, 8 November 2009 (UTC)[reply]

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