71P/Clark

{{Short description|Periodic comet with 5 year orbit}}

{{Infobox comet

| name=71P/Clark

| image= 71P 2017-09-09 NEOWISE image 3-color.png

| discoverer=Michael Clark

| discovery_date=June 9, 1973

| designations=1973 V; 1978 XXIII; 1984 VIII;
1989 XX; 1994t

| epoch=March 6, 2006

| semimajor=3.124 AU

| perihelion=1.562 AU

| aphelion=4.685 AU

| eccentricity=0.4999

| period=5.521 a

| inclination= 9.4883°

| last_p=2023-Jan-21{{mpc|71p}}
June 30, 2017{{cite web

|date=2011-02-06

|title=71P/Clark (NK 2030)

|publisher=OAA Computing and Minor Planet Sections

|author=Syuichi Nakano

|author-link=Syuichi Nakano

|url=http://www.oaa.gr.jp/~oaacs/nk/nk2030.htm

|access-date=2012-02-18}}
December 15, 2011

| next_p=2028-Sep-28{{cite web

|title=Horizons Batch for 71P/Clark (90000724) on 2028-Sep-28

|publisher=JPL Horizons

|type=Perihelion occurs when rdot flips from negative to positive

|url=https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27DES%3D71P%3BCAP%27&START_TIME=%272028-Sep-28%27&STOP_TIME=%272028-Sep-30%27&STEP_SIZE=%273%20hours%27&QUANTITIES=%2719%27

|accessdate=2023-07-06}} (Soln.date: 2023-Jul-05)

}}

71P/Clark is a periodic comet in the Solar System with an orbital period of 5.5 years.

It was discovered by Michael Clark at Mount John University Observatory, New Zealand on 9 June 1973 with a brightness of apparent magnitude 13. Subsequently it has been observed in 1978, 1984, 1989, 1995, 2000, 2006, 2011{{cite web| url = http://cometography.com/pcomets/071P.html| title= 71P/Clark|publisher= Cometography|access-date = 25 February 2015}} and 2017.{{cite web| url = https://apod.nasa.gov/apod/ap170527.html| title= APOD 2017, May 27 - Comet Clark is near the Edge|access-date = 27 May 2017}}

The nucleus of the comet has a radius of 0.68 ± 0.04 kilometers, assuming a geometric albedo of 0.04, based on observations by Hubble Space Telescope,{{cite journal |last1=Lamy |first1=P. L. |last2=Toth |first2=I. |last3=Weaver |first3=H. A. |last4=A'Hearn |first4=M. F. |last5=Jorda |first5=L. |title=Properties of the nuclei and comae of 13 ecliptic comets from Hubble Space Telescope snapshot observations |journal=Astronomy & Astrophysics |date=December 2009 |volume=508 |issue=2 |pages=1045–1056 |doi=10.1051/0004-6361/200811462|bibcode=2009A&A...508.1045L |s2cid=125249770 |doi-access=free }} while observations by Keck indicate a radius of 1.305 km.{{cite journal |last1=Meech |first1=K.J. |last2=Hainaut |first2=O.R. |last3=Marsden |first3=B.G. |title=Comet nucleus size distributions from HST and Keck telescopes |journal=Icarus |date=August 2004 |volume=170 |issue=2 |pages=463–491 |doi=10.1016/j.icarus.2004.03.014|bibcode=2004Icar..170..463M }}