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Spacewatch

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C/2011 KP36 (Spacewatch)

Spacewatch is a comet in the Jupiter-family comet (P < 20 y) orbit class. Its orbit takes it from 4.88 AU to 71.94 AU from the Sun; one orbit takes 238.1 years; it is about 55 km across. Orbit from the JPL solution of 10 May 2023.

Where is it now

Distance from Sun
20.786 AU
True anomaly
129.91°
Distance from Earth
20.879 AU
As of
24 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.

Sun Earth — 0.994 AU from the Sun Earth Spacewatch — 20.786 AU from the Sun Spacewatch
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Spacewatch is 20.879 AU from Earth today (2.9 light-hours).

In the sky

Right ascension
08h 28m 13s
Declination
+04° 23′ 10″
Constellation
Hydra
Distance from Earth
20.87 AU
Elongation from the Sun
83.72° — 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
38.411 AU
Eccentricity
0.8729
Inclination
18.99°
Orbital period
238.1 years
Perihelion
4.883 AU
Aphelion
71.94 AU
Longitude of ascending node
173.4°
Argument of periapsis
180.59°
Epoch · J2000
2457561.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 1,509.4 LD
3.8786 AU
Tisserand (Jupiter)
2.643

Orbit quality

Orbit very well determined (uncertainty code 1).

Observations used
3,711
Data arc
8.83 years
First observed
21 May 2011
Last observed
20 March 2020
Residual RMS
0.41 ″
Solution · Otto Matic
10 May 2023

Physical properties

Mean radius
28 km

Visual & observation

Geometric albedo
0.101
Absolute magnitude (H)
7.5
Total magnitude M₁ · K₁ 7
7.5

Discovery & classification

Also known as 2011 KP36

Named

Sources