Tempel 1

9P/Tempel

Composite of images of nucleus obtained by the Deep Impact impactor
Discovery
Discovered byWilhelm Tempel
Discovery dateApril 3, 1867
Designations
  • 9P/1867 G1
  • 1867 II
  • 9P/1873 G1
  • 1873 I
  • 1873a
  • 1879 III
  • 1879b
  • 9P/1967 L1
  • 1966 VII
  • 9P/1972 A1
  • 1972 V
  • 1972a
  • 1978 II
  • 1977i
  • 1983 XI
  • 1982j
  • 1989 I
  • 1987e1
  • 1994 XIX
  • 1993c
Orbital characteristics
Epoch2023-02-25[1]
Aphelion4.757 AU
Perihelion1.545 AU[1]
(1.77 AU after 2024 Jupiter approach)[2][3]
Semi-major axis3.151 AU
Eccentricity0.5097
Orbital period5.59 years (2,040 days)
Inclination10.474°
68.64°
Argument of
periapsis		179.54°
Last perihelionMarch 4, 2022[1]
August 2, 2016[1]
Next perihelion2028-Feb-12[3]
Earth MOID0.52 AU (78 million km)
Physical characteristics
Dimensions7.6 km × 4.9 km (4.7 mi × 3.0 mi)[4][5]
Mass7.2×1013 to 7.9×1013 kg[5][6]
Mean density
0.62 g/cm3[7]
40.7 hours[4]

Tempel 1 (official designation: 9P/Tempel) is a periodic Jupiter-family comet discovered by Wilhelm Tempel in 1867. It completes an orbit of the Sun every 5.6 years. Tempel 1 was the target of the Deep Impact space mission, which photographed a deliberate high-speed impact upon the comet in 2005. It was re-visited by the Stardust spacecraft on February 14, 2011, and came back to perihelion in August 2016. On 26 May 2024, it will make a modest approach of 0.55 AU to Jupiter[4][2] which will lift the perihelion distance and 9P will next come to perihelion on 12 February 2028 when it will be 1.77 AU from the Sun.[3]

  1. ^ a b c d MPC
  2. ^ a b Cite error: The named reference cometography was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Horizons2028 was invoked but never defined (see the help page).
  4. ^ a b c "JPL Small-Body Database Browser: 9P/Tempel 1" (2023-01-03 last obs). Retrieved 2008-12-16.
  5. ^ a b "Comet 9P/Tempel 1". The Planetary Society. Archived from the original on 2006-02-09. Retrieved 2008-12-16.
  6. ^ Using a spherical diameter of 6.25 km; volume of a sphere * a rubble pile density of 0.62 g/cm3 yields a mass (m=d*v) of 7.9E+13 kg
  7. ^ D. T. Britt; G. J. Consol-magno SJ; W. J. Merline (2006). "Small Body Density and Porosity: New Data, New Insights" (PDF). Lunar and Planetary Science XXXVII. Retrieved 2008-12-16.