19521 Chaos

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19521 Chaos
The orbit of 19521 Chaos (white) compared Pluto and the four giant planets: Jupiter, Saturn, Uranus and Neptune with positions for 2019.
Discovered byDeep Ecliptic Srvy.
Discovery date19 November 1998
MPC designation(19521) Chaos
Named after
1998 WH24
TNO (cubewano)[1][2]
Orbital characteristics[4]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 3
Observation arc5902 days (16.16 yr)
Earliest precovery date17 October 1991
Aphelion50.636 AU (7.5750 Tm)
Perihelion40.957 AU (6.1271 Tm)
45.796 AU (6.8510 Tm)
309.92 yr (113199 d)
4.3931 km/s
0° 0m 11.449s / day
Jupiter MOID35.8 AU (5.36 Tm)
Neptune MOID12.5 AU (1.87 Tm)[3]
Physical characteristics
3.985 d
5.0 [5]

19521 Chaos /ˈk.ɒs/ is a cubewano, a Kuiper-belt object not in resonance with any planet. It is a likely dwarf planet. Chaos was discovered in 1998 by the Deep Ecliptic Survey with Kitt Peak's 4 m telescope. Its albedo is 0.050+0.030
,[6] making it, with its absolute magnitude (H) of 4.8,[4] 600+140
in diameter.[6] It is named after the primeval state of existence in Greek mythology, from which the first gods appeared.


19521 Chaos has an orbital period of approximately 309 years. Its orbit is longer, but less eccentric than the orbit of Pluto. 19521 Chaos's orbit is inclined approximately 12° to the ecliptic. Its orbit never crosses the orbit of Neptune. Currently, the closest approach possible to Neptune (MOID) is 12.5 AU (1.87 billion km).[3]

Chaos moves west to east (right to left) across the sky, discovered in Taurus in 1998, and precovered back to 1991.
Chaos-qe chart.png
Chaos is a classical nonresonant Kuiper belt object
Chaos-distance from earth.png
Distance from earth (AU)
Apparent magnitude from earth
Chaos is at perihelion around 2035, coming as close as 40 AUs from the earth. It's brightest magnitude will be 20.8.

Physical characteristics[edit]

Chaos is a dark object, with an albedo estimated at 5%, implying a diameter of 600 km. Its rotation rate is slow at 3.985 days. According to Brown, it is a likely dwarf planet.[5]

Size comparison between Pluto and Chaos


  1. ^ "MPEC 2008-O05 : Distant Minor Planets (2008 AUG. 2.0 TT)". Minor Planet Center. 17 July 2008. Retrieved 2011-01-08.
  2. ^ Marc W. Buie (2004-11-09). "Orbit Fit and Astrometric record for 19521". SwRI (Space Science Department). Retrieved 2008-09-28.
  3. ^ a b "(19521) Chaos = 1998 WH24 Orbit". IAU Minor Planet Center. Retrieved 2018-02-10.
  4. ^ a b c "JPL Small-Body Database Browser: 19521 Chaos (1998 WH24)" (2007-12-14 last obs). Retrieved 11 April 2016.
  5. ^ a b c Michael E. Brown. "How many dwarf planets are there in the outer solar system? (updates daily)". California Institute of Technology. Retrieved 25 Dec 2018.
  6. ^ a b c d “TNOs are Cool”: A survey of the trans-Neptunian region VI. Herschel/PACS observations and thermal modeling of 19 classical Kuiper belt objects E. Vilenius, C. Kiss, M. Mommert, T. Müller, P. Santos-Sanz, A. Pal, J. Stansberry, M. Mueller, N. Peixinho, S. Fornasier, E. Lellouch, A. Delsanti, A. Thirouin, J. L. Ortiz, R. Duffard, D. Perna, N. Szalai, S. Protopapa, F. Henry, D. Hestroffer, M. Rengel, E. Dotto, & P. Hartogh

External links[edit]