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Comet

Harrington

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51P/Harrington-D

Where is it now

Distance from Sun
5.646 AU
True anomaly
188.63°
Distance from Earth
6.539 AU
As of
22 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 — 0.995 AU from the Sun Earth Harrington — 5.646 AU from the Sun Harrington
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Harrington is 6.539 AU from Earth today (54.4 light-minutes).

In the sky

Right ascension
12h 28m 23s
Declination
+01° 59′ 05″
Constellation
Virgo
Distance from Earth
6.54 AU
Elongation from the Sun
24.44° — near the Sun — look low at dusk or dawn

Visible from both hemispheres.

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
3.709 AU
Eccentricity
0.5424
Inclination
5.43°
Orbital period
7.14 years
Perihelion
1.697 AU
Aphelion
5.722 AU
Longitude of ascending node
83.68°
Argument of periapsis
269.23°
Epoch · J2000
2458624.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 273.7 LD
0.7034 AU
Tisserand (Jupiter)
2.815

Orbit quality

Orbit very well determined (uncertainty code 1).

Observations used
142
Data arc
7.48 years
First observed
30 May 2015
Last observed
21 November 2022
Residual RMS
0.69 ″
Solution · Davide Farnocchia
4 May 2023

Visual & observation

Absolute magnitude (H)
18.5
Total magnitude M₁ · K₁ 5.8
18.5

Discovery & classification

Also known as 51P-D

Named

Close approaches 6 on record

When (UTC) Body Distance Lunar distances Relative speed
2039-04-21 06:21:00 Juptr 0.4319 AU 168.1 LD 5.6 km/s
2039-04-21 06:21:00 Jupiter 0.4319 AU 168.1 LD 5.6 km/s
2087-12-30 00:25:00 Jupiter 0.167 AU 65.0 LD 5.3 km/s
2087-12-30 00:25:00 Juptr 0.167 AU 65.0 LD 5.3 km/s

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

Sources