4179 Toutatis
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Discovery
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| Discovered by | Christian Pollas |
| Discovery date | January 4, 1989 |
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Designations
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| Alternative names | 1934 CT; 1989 AC |
| Minor planet category |
Apollo, Alinda, Mars-crosser |
| Epoch October 22, 2004 (JD 2453300.5) | |
| Aphelion | 616.914 Gm (4.128 AU) |
| Perihelion | 137.739 Gm (0.934 AU) |
| Semi-major axis | 377.326 Gm (2.531 AU) |
| Eccentricity | 0.630 |
| Orbital period | 1471.15 d (4.03 a) |
| Average orbital speed | 16.69 km/s |
| Mean anomaly | 219.29° |
| Inclination | 0.445° |
| Longitude of ascending node | 124.45° |
| Argument of perihelion | 279.65° |
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Physical characteristics
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| Dimensions | 4.5×2.4×1.9 km |
| Mass | 5.0×1013 kg |
| Mean density | 2.1 g/cm³ |
| Equatorial surface gravity | 0.0010 m/s² |
| Escape velocity | 0.0019 km/s |
| Rotation period | 5.41 to 7.33 d[1] |
| Albedo | 0.13[1] |
| Temperature | ~174 K |
| Spectral type | S |
| Absolute magnitude | 15.30[1] |
4179 Toutatis/1989 AC (pronounced /tuːˈtɑːtɨs/ too-taa'-tis) is an Apollo, Alinda, and Mars-crosser asteroid with a chaotic orbit produced by a 3:1 resonance with the planet Jupiter. Due to its very low orbital inclination (0.47°) and its orbital period of very nearly 4 years, Toutatis makes frequent close approaches to Earth, with a currently minimum possible distance (Earth MOID) of just 0.006 AU (2.3 times as far as the Moon).[1] The approach on September 29, 2004 was particularly close, at 0.0104 AU (within 4 lunar distances) from Earth, presenting a good opportunity for observation. The next close approach will be 0.0502 AU on November 9, 2008 at 12:23 UTC.[2]
Its rotation combines two separate periodic motions into a non-periodic result; to someone on the surface of Toutatis the Sun would seem to rise and set in apparently random locations and at random times at the asteroid's horizon.
It was first sighted on February 10, 1934 as object 1934 CT and then promptly lost. It was recovered on January 4, 1989 by Christian Pollas and was named after the Celtic god Toutatis/Teutates, known to popular culture as Astérix's village-god.
Radar imagery has shown that Toutatis is a highly irregular body consisting of two distinct "lobes", with maximum widths of about 4.6 km and 2.4 km respectively. It is hypothesized that Toutatis formed from two originally separate bodies which coalesced at some point, with the resultant asteroid being compared to a "rubble pile".
[edit] See also
[edit] References
[edit] External links
- Toutatis radar information
- Toutatis Home Page - by one of the asteroid's discoverers
- Space.com: Video of Toutatis's close approach to Earth, 29 Sept, 2004
- Interesting views of asteroid
- Astrobiology Magazine article
- Simulating the orbit of Toutatis exposes its resonance with Jupiter
- Orbital simulation from JPL (Java) / Ephemeris
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