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Comet

Forbes

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37P/Forbes

Where is it now

Distance from Sun
4.748 AU
True anomaly
153.86°
Distance from Earth
4.346 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 Forbes — 4.748 AU from the Sun Forbes
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Forbes is 4.346 AU from Earth today (36.1 light-minutes).

In the sky

Right ascension
06h 01m 55s
Declination
+31° 34′ 08″
Constellation
Auriga
Distance from Earth
4.34 AU
Elongation from the Sun
108.48° — 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
3.458 AU
Eccentricity
0.5342
Inclination
8.96°
Orbital period
6.43 years
Perihelion
1.611 AU
Aphelion
5.305 AU
Longitude of ascending node
314.58°
Argument of periapsis
330.02°
Epoch · J2000
2458673.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 234.1 LD
0.6016 AU
Tisserand (Jupiter)
2.866

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
1,737
Data arc
13.91 years
First observed
8 February 2011
Last observed
5 January 2025
Residual RMS
0.6 ″
Solution · Shantanu Naidu
23 November 2025

Physical properties

Mean radius
0.96 km

Visual & observation

Absolute magnitude (H)
9.6
Total magnitude M₁ · K₁ 21.3
9.6

Discovery & classification

Discovered by
Forbes, A. F. I.
Discovery date
1 August 1929
Discovery site
Rosebank, South Africa

Also known as 37P · 1929 II · 1929c · 1942 III · 1948 VIII · 1948e · 1961 VI · 1961a

Named

Close approaches 17 on record

Flyby geometry
Ecliptic flyby of Forbes at 2131-07-20 08:35 UTC Top-down view of the ecliptic, Earth at the centre, for the 2131-07-20 08:35 UTC close approach of Forbes. Catalogue miss distance 77.3 LD · 2.97 × 10⁷ km. The curve is the geocentric path from 2131-07-17 to 2131-07-23, with a mark at UTC midnights and an arrow for the direction of motion. The circle is the Moon’s mean orbit; the Moon is plotted at closest approach. A ray shows the Sun’s direction. The labelled distance is the full separation. The drawn radius is the part that lies in the ecliptic plane. The path is approximate: a two-body Kepler propagation of the catalogue orbital elements, not a numerical integration. The Moon’s position is approximate. The inset is a heliocentric view and is approximate. approximate Sun 77.3 LD · 2.97 × 10⁷ km 2131-07-20 08:35 UTC Earth Moon Heliocentric, approximate

Top-down view of the ecliptic, Earth at the centre, for the 2131-07-20 08:35 UTC close approach of Forbes. Catalogue miss distance 77.3 LD · 2.97 × 10⁷ km. The curve is the geocentric path from 2131-07-17 to 2131-07-23, with a mark at UTC midnights and an arrow for the direction of motion. The circle is the Moon’s mean orbit; the Moon is plotted at closest approach. A ray shows the Sun’s direction. The labelled distance is the full separation. The drawn radius is the part that lies in the ecliptic plane. The path is approximate: a two-body Kepler propagation of the catalogue orbital elements, not a numerical integration. The Moon’s position is approximate. The inset is a heliocentric view and is approximate.

When (UTC) Body Distance Lunar distances Relative speed
2073-10-04 17:02:00 Jupiter 0.2628 AU 102.3 LD 6.1 km/s
2073-10-04 17:02:00 Juptr 0.2628 AU 102.3 LD 6.1 km/s
2085-08-22 14:40:00 Juptr 0.4358 AU 169.6 LD 6.5 km/s
2085-08-22 14:40:00 Jupiter 0.4358 AU 169.6 LD 6.5 km/s
2131-07-20 08:35:00 Earth 0.1985 AU 77.3 LD 9.4 km/s
2144-06-21 03:28:00 Juptr 1.0279 AU 400.0 LD 7 km/s
2156-09-07 22:04:00 Juptr 0.2316 AU 90.1 LD 6 km/s
2156-09-07 22:04:00 Jupiter 0.2316 AU 90.1 LD 6 km/s
2168-08-25 15:48:00 Jupiter 0.2979 AU 115.9 LD 6.1 km/s
2168-08-25 15:48:00 Juptr 0.2979 AU 115.9 LD 6.1 km/s

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

Sources