103P/Hartley

103P/Hartley
	Photograph from close approach by EPOXI mission
Discovery
Discovered by	Malcolm Hartley
Discovery date	15 March 1986
Designations
Alternative designations	103P/1986 E2
Orbital characteristics
Epoch	2023-10-23
Aphelion	5.89 AU (Q)
Perihelion	1.06 AU (q)
Semi-major axis	3.48 AU (a)
Eccentricity	0.694
Orbital period	6.48 years
Inclination	13.61°
Last perihelion	20 April 2017; 28 October 2010
Next perihelion	2023-Oct-12; 2030-Apr-05
Earth MOID	0.072 AU (10,800,000 km)

Comet Hartley 2, designated as 103P/Hartley by the Minor Planet Center,^[6] is a small periodic comet with an orbital period of 6.48 years.^[1] It was discovered by Malcolm Hartley in 1986 at the Schmidt Telescope Unit, Siding Spring Observatory, Australia.^[5] Its diameter is estimated to be 1.2 to 1.6 kilometres (0.75 to 0.99 mi).^[5]^[7]

Hartley 2 was the target of a flyby of the Deep Impact spacecraft, as part of the EPOXI mission, on 4 November 2010,^[8] which was able to approach within 700 kilometers (430 mi) of Hartley 2 as part of its extended mission.^[9] As of November 2010^[update] Hartley 2 is the smallest comet which has been visited.^[10] It is the fifth comet visited by spacecraft, and the second comet visited by the Deep Impact spacecraft, which first visited comet Tempel 1 on 4 July 2005.^[11]

^ ^a ^b ^c MPC
^ ^a ^b Cite error: The named reference Yoshida-103p was invoked but never defined (see the help page).
^ Syuichi Nakano (13 October 2010). "103P/Hartley 2 (NK 2000)". OAA Computing and Minor Planet Sections. Retrieved 20 February 2012.
^ Cite error: The named reference Horizons2030 was invoked but never defined (see the help page).
^ ^a ^b ^c Cite error: The named reference jpldata was invoked but never defined (see the help page).
^ Cite error: The named reference PeriodicCodes was invoked but never defined (see the help page).
^ Cite error: The named reference epoxi_status was invoked but never defined (see the help page).
^ Tune, Lee; Steigerwald, Bill; Hautaluoma, Grey; Agle, D.C. (13 December 2007). "Deep Impact Extended Mission Heads for Comet Hartley 2". University of Maryland, College Park. Archived from the original on 20 June 2009. Retrieved 7 August 2009.
^ Cite error: The named reference Lisse2009 was invoked but never defined (see the help page).
^ Cite error: The named reference S&T20101104 was invoked but never defined (see the help page).
^ "UMD Leads Deep Impact Spacecraft on Successful Flyby of Comet Hartley 2" (Press release). NASA. 4 November 2010. Archived from the original on 12 December 2012. Retrieved 7 November 2010.

[MPC-1] MPC

[Yoshida-103p-2] Cite error: The named reference Yoshida-103p was invoked but never defined (see the help page).

[NK2000-3] Syuichi Nakano (13 October 2010). "103P/Hartley 2 (NK 2000)". OAA Computing and Minor Planet Sections. Retrieved 20 February 2012.

[Horizons2030-4] Cite error: The named reference Horizons2030 was invoked but never defined (see the help page).

[jpldata-5] Cite error: The named reference jpldata was invoked but never defined (see the help page).

[PeriodicCodes-6] Cite error: The named reference PeriodicCodes was invoked but never defined (see the help page).

[epoxi_status-7] Cite error: The named reference epoxi_status was invoked but never defined (see the help page).

[NASASSE-8] Tune, Lee; Steigerwald, Bill; Hautaluoma, Grey; Agle, D.C. (13 December 2007). "Deep Impact Extended Mission Heads for Comet Hartley 2". University of Maryland, College Park. Archived from the original on 20 June 2009. Retrieved 7 August 2009.

[Lisse2009-9] Cite error: The named reference Lisse2009 was invoked but never defined (see the help page).

[S&T20101104-10] Cite error: The named reference S&T20101104 was invoked but never defined (see the help page).

[epoxi_1-11] "UMD Leads Deep Impact Spacecraft on Successful Flyby of Comet Hartley 2" (Press release). NASA. 4 November 2010. Archived from the original on 12 December 2012. Retrieved 7 November 2010.

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