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Comet

Schwassmann-Wachmann

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29P/Schwassmann-Wachmann 1

Where is it now

Distance from Sun
6.317 AU
True anomaly
181.86°
Distance from Earth
7.225 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 Schwassmann-Wachmann — 6.317 AU from the Sun Schwassmann-Wachmann
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Schwassmann-Wachmann is 7.225 AU from Earth today (1.0 light-hours).

In the sky

Right ascension
12h 19m 10s
Declination
-09° 08′ 52″
Constellation
Virgo
Distance from Earth
7.22 AU
Elongation from the Sun
23.1° — 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
6.046 AU
Eccentricity
0.0448
Inclination
9.36°
Orbital period
14.87 years
Perihelion
5.775 AU
Aphelion
6.317 AU
Longitude of ascending node
312.39°
Argument of periapsis
50.66°
Epoch · J2000
2459866.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 1,860.2 LD
4.78 AU
Tisserand (Jupiter)
2.986

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
739
Data arc
15.97 years
First observed
17 February 2009
Last observed
5 February 2025
Residual RMS
0.37 ″
Solution · Shantanu Naidu
14 April 2025

Physical properties

Mean radius
30 km

Visual & observation

Geometric albedo
0.033
Absolute magnitude (H)
10.1
Total magnitude M₁ · K₁ 4.5
10.1

Discovery & classification

Discovered by
Schwassmann, A. and Wachmann, A. A.
Discovery date
15 November 1927
Discovery site
Hamburg Observatory, Germany

Also known as 29P · 1908 IV · 1925 II · 1927i · 1941 VI · 1957 IV · 1974 II · 1989 XV

Named

Close approaches 6 on record

When (UTC) Body Distance Lunar distances Relative speed
2037-10-11 14:16:00 Juptr 0.9022 AU 351.1 LD 2.5 km/s
2084-05-18 17:09:00 Juptr 1.4745 AU 573.8 LD 2.1 km/s
2126-01-22 11:04:00 Juptr 1.6049 AU 624.6 LD 2.6 km/s
2167-07-31 15:27:00 Juptr 1.4164 AU 551.2 LD 2.3 km/s

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

Sources