1866 Sisyphus

1866 Sisyphus
Discovery
Discovered by Paul Wild
Discovery date December 5, 1972
Designations
Named after
 Sisyphus
1972 XA
Apollo, Mars crosser
Orbital characteristics
Epoch December 1, 2005 (JD 2453705.5)
Aphelion 435.936 Gm
(2.914 AU)
Perihelion 130.751 Gm
(0.874 AU)
283.343 Gm
(1.894 AU)
Eccentricity 0.539
952.094 d(2.607 a)
19.977 km/s
261.365°
Inclination 41.181°
63.600°
293.033°
Physical characteristics
Dimensions 8.48 ± 1.27 km
Mean density
 1.6 g/cm3 (estimate)
2.7 h
2.4 h (JPL)
Albedo 0.15 ± 0.045
Spectral type
 S
12.237
12.4 (JPL)

    1866 Sisyphus (/ˈsɪsɨfəs/ SIS-i-fəs) is a binary[1] Apollo asteroid which, at approximately 9 km in diameter, is the largest of the Earth-crossing asteroids.[2] It is comparable in size to the Chicxulub object whose impact may have killed off the dinosaurs.

    Sisyphus was discovered in 1972 by Paul Wild, and named after the Sisyphus of Greek mythology.

    It will pass 0.11581 AU (17,325,000 km; 10,765,000 mi) from Earth on November 24, 2071,[3] and will peak at roughly apparent magnitude 9.3 on November 26, 2071.[4] When it was discovered it peaked at magnitude 9.0 on November 25, 1972. It is one of the brightest near-Earth asteroids.

    In 1985, this object was detected with radar from the Arecibo Observatory at a distance of 0.25 AU. The measured radar cross-section was 8 km2.[5] During the radar observations, a small satellite was detected, although its existence was not reported until December 2007. As a result, little is known about the moon.

    Larger near-Earth asteroids include: 1036 Ganymed (32 km), 3552 Don Quixote (19 km), 433 Eros (17 km), and 4954 Eric (10.8 km).

    See also

    References

    1. ↑ http://echo.jpl.nasa.gov/~lance/binary.neas.html
    2. ↑ "JPL Small-Body Database Search Engine: asteroids and NEOs and H < 13 (mag)". JPL Solar System Dynamics. Retrieved 2013-10-31.
    3. ↑ "JPL Close-Approach Data: 1866 Sisyphus (1972 XA)" (last observation: 2013-07-26). Retrieved 2013-10-30.
    4. ↑ "(1866) Sisyphus Ephemerides for November 2071". NEODyS (Near Earth Objects – Dynamic Site). Retrieved 2013-10-30.
    5. ↑ Ostro, S. J. et al. (October 1991), "Asteroid radar astrometry", Astronomical Journal 102: 1490–1502, Bibcode:1991AJ....102.1490O, doi:10.1086/115975.

    External links