8P/Tuttle

8P/Tuttle (also known as Tuttle's Comet or Comet Tuttle) is a periodic comet with a 13.6-year orbit. It fits the classical definition of a Jupiter-family comet with an orbital period of less than 20 years, but does not fit the modern definition of (2 < T_Jupiter< 3).^[2] Its last perihelion passage was 27 August 2021 when it had a solar elongation of 26 degrees at approximately apparent magnitude 9.^[5] Two weeks later, on September 12, 2021, it was about 1.8 AU (270 million km) from Earth which is about as far from Earth as the comet can get when the comet is near perihelion.

8P/Tuttle

Tuttle's Comet and the Triangulum Galaxy photographed from Mount Laguna, California on December 30, 2007
Discovery
Discovered by	Horace Parnell Tuttle
Discovery date	January 5, 1858
Designations
MPC designation	P/1790 A2; P/1858 A1 P/1871 T1
Alternative designations	1790 II; 1858 I; 1871 III; 1885 IV; 1899 III; 1912 IV; 1926 IV; 1939 X; 1967 V; 1980 XIII; 1994 XV
Orbital characteristics[1][2]
Epoch	January 21, 2022 (JD 2459600.5)
Observation arc	14.09 years (5,150 days)
Number of observations	316
Aphelion	10.39 AU
Perihelion	1.026 AU
Semi-major axis	5.707 AU
Eccentricity	0.82023
Orbital period	13.6 years
Inclination	54.911°
Longitude of ascending node	270.20°
Argument of periapsis	207.49°
Mean anomaly	10.573°
Last perihelion	August 27, 2021[1][3]
Next perihelion	April 18, 2035[4]
TJupiter	1.601
Earth MOID	0.095 AU
Jupiter MOID	0.738 AU
Physical characteristics[2]
Dimensions	4.5 km (2.8 mi)
Comet total magnitude (M1)	14.6

Comet 8P/Tuttle is responsible for the Ursid meteor shower in late December.^[6]

2008 perihelion

Under dark skies, the comet was a naked-eye object. On December 30, 2007, it was in close conjunction with the Triangulum Galaxy. On January 1, 2008, it passed Earth at a distance of 0.25282 AU (37.821 million km).^[2] It was visible telescopically to Southern Hemisphere observers in the constellation Eridanus throughout February 2008.

Predictions that the 2007 Ursid meteor shower could have possibly been stronger than usual due to the return of the comet,^[7] did not appear to materialize, as counts were in the range of normal distribution.

Contact binary

Radar observations of Comet Tuttle in January 2008 by the Arecibo Observatory show it to be a contact binary.^[8][9] The comet nucleus is estimated at 4.5 km (2.8 mi) in diameter, using the equivalent diameter of a sphere having a volume equal to the sum of a 3 km × 4 km (1.9 mi × 2.5 mi) sphere.^[2]

Additional images

Animation of 8P/Tuttle from 2005 to 2025
  Sun ·   Venus ·   Earth ·   Mars ·   Jupiter ·   Saturn ·   8P/Tuttle

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  8P/Tuttle on December 3, 2007 from Mount Laguna, California
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  8P/Tuttle about 1.2 degrees from M33 on December 30, 2007.
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  8P/Tuttle on Feb 2, 2008 from the Red Sea coast of Egypt.