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Comet

Gehrels

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78P/Gehrels 2

Where is it now

Distance from Sun
2.232 AU
True anomaly
46.3°
Distance from Earth
1.941 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 Gehrels — 2.232 AU from the Sun Gehrels
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Gehrels is 1.941 AU from Earth today (16.1 light-minutes).

In the sky

Right ascension
07h 47m 30s
Declination
+14° 51′ 23″
Constellation
Gemini
Distance from Earth
1.94 AU
Elongation from the Sun
93.62° — well clear of the Sun

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
3.738 AU
Eccentricity
0.4611
Inclination
6.25°
Orbital period
7.23 years
Perihelion
2.014 AU
Aphelion
5.462 AU
Longitude of ascending node
210.56°
Argument of periapsis
192.72°
Epoch · J2000
2457611.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 398.4 LD
1.0237 AU
Tisserand (Jupiter)
2.887

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
6,376
Data arc
15.45 years
First observed
3 May 2011
Last observed
14 October 2026
Residual RMS
0.6 ″
Solution · Shantanu Naidu
14 October 2026

Visual & observation

Absolute magnitude (H)
9.1
Total magnitude M₁ · K₁ 13.3
9.1

Discovery & classification

Discovered by
Gehrels, Tom
Discovery date
29 September 1973

Also known as 78P · 1973 XI · 1973n · 1981 XVII · 1981f · 1989 XVII · 1989n · 78P/1973 S1

Named

Close approaches 10 on record

When (UTC) Body Distance Lunar distances Relative speed
2029-09-15 17:16:00 Jupiter 0.0183 AU 7.1 LD 10.2 km/s
2029-09-15 17:16:00 Juptr 0.0183 AU 7.1 LD 10.2 km/s
2038-03-09 22:15:00 Juptr 1.9207 AU 747.5 LD 3.3 km/s
2046-10-18 15:32:00 Juptr 0.0506 AU 19.7 LD 6.8 km/s
2046-10-18 15:32:00 Jupiter 0.0506 AU 19.7 LD 6.8 km/s

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

Sources