Skip to content
Public Universe
Comet

Clark

Add to an observing list or journal →

71P/Clark

Where is it now

Distance from Sun
4.295 AU
True anomaly
205.08°
Distance from Earth
4.488 AU
As of
11 October 2026

Two-body Kepler propagation — accurate to ~0.1% for major planets over decades, less so for highly-perturbed bodies. Use JPL Horizons for high precision.

Orbit of Mercury Orbit of Venus Orbit of Mars Sun Earth — 0.998 AU from the Sun Earth Clark — 4.295 AU from the Sun Clark
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Clark is 4.488 AU from Earth today (37.3 light-minutes).

In the sky

Right ascension
08h 42m 03s
Declination
+25° 49′ 33″
Constellation
Cancer
Distance from Earth
4.48 AU
Elongation from the Sun
73.06° — well clear of the Sun

Favours the northern hemisphere; low or below the horizon from far south.

From your location

See how high it is right now, whether it is up after civil twilight, and when it rises and sets where you are.

How do I find my coordinates?

Google Maps on a computer

  1. Right-click the spot where you'll be observing.
  2. The first line of the menu is the coordinates, e.g. 51.50722, -0.12758 — click it and they're copied.
  3. Paste them above.

Google Maps on a phone

  1. Press and hold the spot to drop a pin.
  2. The coordinates appear in the search bar (or on the pin's card) — tap to copy, then paste above.

A full Google Maps link works too, but the short maps.app.goo.gl share links don't carry coordinates — copy the numbers instead. We round to about a kilometre; that's all the sky calculation needs.

Know your what3words address? Paste it, e.g. ///filled.count.soap. This is optional — the three words are sent to what3words to convert them, and we don't store the address or the result.

Your location stays in your browser and is sent only for this calculation. Using a what3words address is optional; if you do, the three words go to what3words to be converted and we don't record them. Set a location first, then you can save an email alert for this object. See our privacy policy.

Two-body approximation, good to about a degree for the planets — enough to find the constellation and know whether it is up.

Orbital elements

Semi-major axis
3.139 AU
Eccentricity
0.4945
Inclination
9.44°
Orbital period
5.56 years
Perihelion
1.587 AU
Aphelion
4.691 AU
Longitude of ascending node
59.44°
Argument of periapsis
208.97°
Epoch · J2000
2458635.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 225.2 LD
0.5787 AU
Tisserand (Jupiter)
2.99

Orbit quality

Orbit very well determined (uncertainty code 1).

Observations used
1,360
Data arc
7.78 years
First observed
4 March 2016
Last observed
15 December 2023
Residual RMS
0.67 ″
Solution · Shantanu Naidu
7 March 2026

Physical properties

Mean radius
0.68 km

Visual & observation

Absolute magnitude (H)
11.1
Total magnitude M₁ · K₁ 14.3
11.1

Discovery & classification

Discovered by
Clark, Michael
Discovery date
9 June 1973
Discovery site
Mount John University Obs., New Zealand

Also known as 71P · 1973 V · 1973i · 1978 XXIII · 1978g · 1983w · 1984 VIII · 1989 XX

Named

Close approaches 10 on record

When (UTC) Body Distance Lunar distances Relative speed
2036-11-30 06:04:00 Juptr 0.5088 AU 198.0 LD 4 km/s
2048-10-28 23:24:00 Juptr 0.5479 AU 213.2 LD 4 km/s
2120-09-14 06:56:00 Juptr 1.2698 AU 494.2 LD 6.5 km/s
2132-05-07 03:43:00 Jupiter 0.4639 AU 180.5 LD 3.5 km/s
2132-05-07 03:43:00 Juptr 0.4639 AU 180.5 LD 3.5 km/s
2143-12-31 02:55:00 Juptr 1.4192 AU 552.3 LD 6.3 km/s

Next ten from today. 1 lunar distance = 384,400 km. Source: JPL close-approach data.

Sources