Talk:4179 Toutatis

This asteroid is listed on Apollo asteroid, but the article itself says it's an Alinda asteroid. Is there crossover between these groups, or is this an indication of a contradiction? Bryan 09:55, 15 Jun 2004 (UTC)

I think it qualifies under both categories, but I'm not an expert. Perhaps you could try asking User:Desertsky (talk), he's a retired professional astronomer who discovered some asteroids. -- Curps 17:39, 15 Jun 2004 (UTC)

Contents

1 .006 AU? 2 Near pass, September 29, 2004 3 Asterix 4 1934 CT 5 Image positioning 6 Comments moved from article 7 More accurate race track sizes

.006 AU?

Article: Toutatis makes close approaches to Earth every four years, with a minimum distance at present of just 0.006 AU. The approach on September 29, 2004 will be particularly close, at 0.0104 AU (within 4 lunar distances) from Earth, presenting a good opportunity for observation.

What does 'minimum distance at present of 0.006 AU' mean? That's just above two lunar distances; does that mean that's the closest it's ever gotten? --Golbez 21:36, Sep 28, 2004 (UTC)

I am glad that 3.99 is clarified as almost an integer.

That "minimum distance" thingy presumably means that if you consider the two orbital ellipses, they are 0.006 AU apart at their closest point. The reason it will be 0.0104 AU away on this pass is that Earth is arriving at the closest point ahead of the asteroid (or vice versa). --P3d0 02:08, Sep 30, 2004 (UTC)

Near pass, September 29, 2004

The asteroid passes within four lunar distances of the Earth on September 29, 2004. The asteroid is the largest known that has ever passed this close to Earth. Are we getting more out of synch every four years (I hope). Or is this the "doomsday asteroid"? Wetman 08:02, 29 Sep 2004 (UTC)

I think the distance of closest approach varies, but in the current orbit, it never gets closer than two moon distances. However, orbits can be perturbed. --P3d0 02:10, Sep 30, 2004 (UTC)

Two moon distances is okay. Any closer is too interesting. Thanks for enriching the entry for folks like me. Wetman

Asterix

I find it very amusing that this asteroid would be named Toutatis... the one thing the strip character Asterix and peers fear is that "the sky would fall on their heads" — and Toutatis is a Gallic sky god! {Ανάριον} 15:46, 29 Sep 2004 (UTC)

1934 CT

Doesn't the designation 1934 CT mean that it was first discovered in 1934? {Ανάριον} 16:45, 29 Sep 2004 (UTC)

Nope, it means it was first spotted in 1934 and promptly lost.

Urhixidur 20:12, 2004 Sep 30 (UTC)

Image positioning

Golbez's positioning of the image (upper left) was pretty good, but I have changed it again. I have put the image at the upper right, and moved the Minor Planet box down. If anyone has a better idea, go for it. --P3d0 12:58, Sep 30, 2004 (UTC)

Much improved format. Those boxes are useful but ugly. Wetman 22:58, 30 Sep 2004 (UTC)

Comments moved from article

Note: I didn't make these myself, but they sound valid and they shouldn't have been on the article page itself. Mackensen

Please clarify how the laws of gravity, the ones that let us put spaceships into orbit around planets, are chaotic and unpredictable. The equation is something simple, like Δx/r².

Sorry, that would be something like GmM/r² where m and M are the respective masses of the interacting gravitational objects and G is another famous constant. Where is the chaos?

(P3d0 13:48, Oct 1, 2004 (UTC)) Chaos can arise from extremely simple formulae, as it does in this case. The classic example is the logistic equation, which exhibits chaotic behaviour despite its simplicity: the formula is just <math>x_{n+1} = rx_n(1 - x_n)<math>. Another classic example is the double pendulum, which has some things in common with three-body gravitational motion. Here are some external links if you are interested to learn more:

• http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=60054
• http://www-chaos.umd.edu/misc/poincare.html

Thanks, Mack. I was just browsing and noticed a scientific article that began to sound "new age" and wondered how chaos theory intersected with Newtonian physics. -Dave

I was about to remove that odd comment myself and place it here, but it seems someone did it between my reading it and the person posting this. I also removed the, "but this analogy breaks down due to the somewhat unpredicable laws of gravity" comment too. Gravity isn't unpredictable. Orbits can be perturbed (and I left that in the article) but they're otherwise very predictable.--Mylon 06:43, 1 Oct 2004 (UTC)--24.92.199.18 06:43, 1 Oct 2004 (UTC)

Ok, fair enough, I don't mind being overruled. But you guys are all thinking of the near-circular planetary orbits whose properties are dominated by the Sun's gravity, and are only slightly perturbed by other bodies; or of moon orbits that are dominated by their planets' gravity. But smaller bodies that wend their way among the planets are much less predictable over the long term.

Please don't take the term "chaotic" to be an indictment of the laws of nature. It simply refers to the fact that any error or uncertainty in a model grows exponentially with time until the model loses all predictive ability. My remarks in this vane were motivated by the fact that this asteroid's orbit is categorized as Chaotic. However, if you guys find that to be misleading, then I'm glad they were removed. --P3d0 11:24, Oct 1, 2004 (UTC)

More accurate race track sizes

If we're going to be more accurate about the racetrack sizes, they would be more like this:

To be the same length as the Indy track, Toutatis' orbit would be 1518 x 1173 m, and earth's would be 602 m. The miss distance this time would be 3.13 m, and minimum miss distance would be 1.80 m. --P3d0 12:50, Oct 2, 2004 (UTC)