Thule, minor planet designation: 279 Thule, is a large asteroid from the outer asteroid belt. It is classified as a D-type asteroid and is probably composed of organic-rich silicates, carbon and anhydrous silicates. Thule was the first asteroid discovered with a semi-major axis greater than 4 AU. It was discovered by Johann Palisa on 25 October 1888 in Vienna and was named aptly after the ultimate northern land of Thule.
|Discovered by||Johann Palisa|
|Discovery date||25 October 1888|
|MPC designation||(279) Thule|
|1927 EC, 1954 FF, A920 GA, A923 RA|
|Asteroid belt (Thule)|
|Epoch 31 July 2016 (JD 2457600.5)|
|Uncertainty parameter 0|
|Observation arc||125.34 yr (45780 d)|
|Aphelion||4.4617880 AU (667.47398 Gm)|
|Perihelion||4.2367660 AU (633.81117 Gm)|
|4.3492770 AU (650.64258 Gm)|
|9.07 yr (3313.0 d)|
|0° 6m 31.184s / day|
|Dimensions||126.59±3.7 km (IRAS)|
|23.896 h (0.9957 d)|
Thule was the first discovered member of the Thule dynamical group, which as of 2008 is known to consist of three objects: 279 Thule, (186024) 2001 QG207, and (185290) 2006 UB219. The orbits of these bodies are unusual. They orbit in the outermost edge of the asteroid belt in a 4:3 orbital resonance with Jupiter, the result of the periodic force Jupiter exerts on a body with Thule's orbital period, in the same way (though with the reverse effect) as the Kirkwood gaps in the more inner parts of the asteroid belt.
- "279 Thule". JPL Small-Body Database. NASA/Jet Propulsion Laboratory. Retrieved 11 May 2016.
- "Thule". Oxford English Dictionary second edition. Oxford University Press. 1989. Retrieved 7 December 2018.
- Brož, M.; Vokrouhlický, D. (2008). "Asteroid families in the first-order resonances with Jupiter". Monthly Notices of the Royal Astronomical Society. 390 (2): 715–732. arXiv:1104.4004. Bibcode:2008MNRAS.390..715B. doi:10.1111/j.1365-2966.2008.13764.x.