10P/Tempel

10P/Tempel
	Comet Tempel 2 photographed by H. M. Jeffers from the Lick Observatory in 1946
Discovery
Discovered by	Wilhelm Tempel
Discovery date	4 July 1873
Designations
MPC designation	P/1873 N1, P/1878 O1
Alternative designations	Tempel 2; 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
Epoch	5 May 2025 (JD 2460800.5)
Observation arc	130.78 years
Number of; observations	5,700
Aphelion	4.710 AU
Perihelion	1.417 AU
Semi-major axis	3.064 AU
Eccentricity	0.53738
Orbital period	5.362 years
Inclination	12.027°
Longitude of; ascending node	117.80°
Argument of; periapsis	195.50°
Mean anomaly	276.53°
Last perihelion	24 March 2021
Next perihelion	2 August 2026
TJupiter	2.965
Earth MOID	0.410 AU
Jupiter MOID	0.622 AU
Physical characteristics
Mean diameter	10.6 km (6.6 mi)
Synodic rotation period	8.948±0.001 hours
Geometric albedo	0.022
Spectral type	(V–R) = 0.561±0.04; (B–V) = 0.80±0.02; (R–I) = 0.52±0.03;
Comet total; magnitude (M1)	14.3

10P/Tempel, also known as Tempel 2, is a Jupiter-family comet with a 5.36-year orbit around the Sun. It was discovered on 4 July 1873 by Wilhelm Tempel. At the perihelion passage on 2 August 2026 the solar elongation is calculated at 164 degrees, with apparent magnitude approximately 8, with closest approach to Earth on 3 August 2026 at a distance of 0.414 AU (61.9 million km).

10P/Tempel closest Earth approach on 2026-Aug-03
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 20:56	0.414 AU (61.9 million km; 38.5 million mi)	1.42 AU (212 million km; 132 million mi)	6.5	31.0	± 200 km	Horizons