10P/Tempel

10P/Tempel
Comet Tempel 2 in 1946 from Lick Observatory
Discovery
Discovered byErnst Wilhelm Leberecht Tempel[1]
Discovery dateJuly 4, 1873
Designations
1873 II; 1878 III; 1894 III;
1899 IV; 1904 III; 1915 I;
1920 II; 1925 IV; 1930 VII;
1946 III; 1951 VIII; 1957 II;
1962 VI; 1967 X; 1972 X;
1978 V; 1983 X; 1988 XIV;
1994 VII;
Orbital characteristics
Epoch2026-07-19
(JD 2461240.5)[2]
Aphelion4.71 AU
Perihelion1.418 AU
Semi-major axis3.065 AU
Eccentricity0.5374
Orbital period5.37 yr
Inclination12.03°
117.8°
Argument of
periapsis		195.5°
Last perihelion24 March 2021[2]
14 November 2015[2][3]
4 July 2010[4][5]
Next perihelion2026-Aug-02[2][6]
Earth MOID0.41 AU (61 million km)
Physical characteristics
Dimensions10.6 km[1]

10P/Tempel, also known as Tempel 2, is a periodic Jupiter-family comet with a 5-year orbital period. It was discovered on July 4, 1873 by Wilhelm Tempel.[7] At the perihelion passage on 2 August 2026 the solar elongation is calculated at 164 degrees, with apparent magnitude approximately 8,[4] with closest approach to Earth on 3 August 2026 at a distance of 0.414 AU (61.9 million km).[1]

10P/Tempel closest Earth approach on 2026-Aug-03[1]
Date & time of
closest approach 		Earth distance
(AU) 		Sun distance
(AU) 		Velocity
wrt Earth
(km/s) 		Velocity
wrt Sun
(km/s) 		Uncertainty
region
(3-sigma) 		Reference
2026-Aug-03 20:59 ± 1 min 0.414 AU (61.9 million km; 38.5 million mi; 161 LD) 1.42 AU (212 million km; 132 million mi) 6.5 31.0 ± 204 km Horizons

The comet nucleus is estimated to be roughly the size of Halley's Comet at 10.6 kilometers in diameter with a low albedo of 0.022.[1] The nucleus is dark because hydrocarbons on the surface have been converted to a dark, tar like substance by solar ultraviolet radiation. The nucleus is large enough that even near aphelion (furthest distance from the Sun which is near the orbit of Jupiter) the comet remains brighter than about magnitude 21.

Comet Tempel II during the 1925 apparition.

During the 2010 apparition the comet brightened to about apparent magnitude 8.[4] The most favorable apparition of 10P/Tempel 2 was in 1925 when it came within 0.35 AU (52 million km; 33 million mi) of Earth with an apparent magnitude of 6.5.[7]

  1. ^ a b c d e Cite error: The named reference jpldata was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference MPC was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference kinoshita was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Yoshida-10p was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference NK1460 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Horizons2026 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference kronk-10p was invoked but never defined (see the help page).