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Comet Near-Earth

Schwassmann-Wachmann

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73P/Schwassmann-Wachmann 3-AH

Where is it now

Distance from Sun
4.058 AU
True anomaly
209°
Distance from Earth
4.317 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 Schwassmann-Wachmann — 4.058 AU from the Sun Schwassmann-Wachmann
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Schwassmann-Wachmann is 4.317 AU from Earth today (35.9 light-minutes).

In the sky

Right ascension
09h 00m 17s
Declination
+25° 06′ 04″
Constellation
Cancer
Distance from Earth
4.31 AU
Elongation from the Sun
68.89° — 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
3.075 AU
Eccentricity
0.6934
Inclination
11.33°
Orbital period
5.39 years
Perihelion
0.943 AU
Aphelion
5.207 AU
Longitude of ascending node
70.71°
Argument of periapsis
197.74°
Epoch · J2000
2453839.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 15.6 LD
0.0402 AU
Tisserand (Jupiter)
2.778

Orbit quality

Orbit very uncertain — the object may be effectively lost (uncertainty code 9).

Observations used
19
Data arc
3 days
First observed
5 April 2006
Last observed
8 April 2006
Residual RMS
0.99 ″
Solution · Nick Mastrodemos
21 April 2006

Discovery & classification

Also known as 73P-AH

Near-Earth Object Named

Sources