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Comet Near-Earth

Hartley

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103P/Hartley 2

Where is it now

Distance from Sun
5.863 AU
True anomaly
176.57°
Distance from Earth
6.813 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 Hartley — 5.863 AU from the Sun Hartley
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Hartley is 6.813 AU from Earth today (56.7 light-minutes).

In the sky

Right ascension
14h 10m 22s
Declination
-13° 35′ 36″
Constellation
Virgo
Distance from Earth
6.82 AU
Elongation from the Sun
16.03° — too close to the Sun to observe

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
3.476 AU
Eccentricity
0.6936
Inclination
13.6°
Orbital period
6.48 years
Perihelion
1.065 AU
Aphelion
5.886 AU
Longitude of ascending node
219.74°
Argument of periapsis
181.32°
Epoch · J2000
2457152.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 28.5 LD
0.0732 AU
Tisserand (Jupiter)
2.642

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
8,768
Data arc
16.98 years
First observed
5 May 2008
Last observed
28 April 2025
Residual RMS
0.55 ″
Solution · Davide Farnocchia
1 May 2025

Physical properties

Mean radius
0.80 km
Rotation period
18.1 hours

Visual & observation

Absolute magnitude (H)
16
Total magnitude M₁ · K₁ 4.5
16

Discovery & classification

Discovered by
Hartley, Malcolm
Discovery date
15 March 1986
Discovery site
U. K. Schmidt Telescope Unit, Siding Spring

Also known as 103P · 103P/1986 E2 · 103P/1991 N1 · 1985 V · 1986c · 1991 XV · 1991t

Near-Earth Object Named

Close approaches 24 on record

When (UTC) Body Distance Lunar distances Relative speed
2054-03-18 20:06:00 Juptr 0.7188 AU 279.8 LD 8.5 km/s
2065-11-13 21:09:00 Jupiter 0.2674 AU 104.1 LD 6.9 km/s
2065-11-13 21:09:00 Juptr 0.2674 AU 104.1 LD 6.9 km/s
2076-12-11 08:48:00 Juptr 0.2461 AU 95.8 LD 7 km/s
2076-12-11 08:48:00 Jupiter 0.2461 AU 95.8 LD 7 km/s
2088-07-29 04:17:00 Juptr 0.4725 AU 183.9 LD 8.1 km/s
2088-07-29 04:17:00 Jupiter 0.4725 AU 183.9 LD 8.1 km/s
2136-12-20 08:56:00 Juptr 1.4449 AU 562.3 LD 10.3 km/s
2148-08-23 11:16:00 Juptr 0.4485 AU 174.5 LD 6.6 km/s
2148-08-23 11:16:00 Jupiter 0.4485 AU 174.5 LD 6.6 km/s

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

Sources