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366P/Spacewatch

Where is it now

Distance from Sun
3.918 AU
True anomaly
128.06°
Distance from Earth
3.064 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 Spacewatch — 3.918 AU from the Sun Spacewatch
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Spacewatch is 3.064 AU from Earth today (25.5 light-minutes).

In the sky

Right ascension
23h 19m 25s
Declination
-16° 25′ 58″
Constellation
Aquarius
Distance from Earth
3.07 AU
Elongation from the Sun
143.63° — well clear of the Sun

Favours the southern hemisphere; low or below the horizon from far north.

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
3.501 AU
Eccentricity
0.3474
Inclination
8.85°
Orbital period
6.55 years
Perihelion
2.285 AU
Aphelion
4.717 AU
Longitude of ascending node
70.8°
Argument of periapsis
153.58°
Epoch · J2000
2455320.5
Orbit class · ETc
Encke-type comet
Earth MOID · 498.0 LD
1.2798 AU
Tisserand (Jupiter)
3.006

Orbit quality

Orbit very well determined (uncertainty code 2).

Observations used
74
Data arc
13.04 years
First observed
4 April 2005
Last observed
20 April 2018
Residual RMS
0.68 ″
Solution · Otto Matic
15 April 2021

Visual & observation

Absolute magnitude (H)
13.1
Total magnitude M₁ · K₁ 17.3
13.1

Discovery & classification

Also known as 366P · 366P/2005 JN · 366P/2018 F2

Named

Close approaches 10 on record

When (UTC) Body Distance Lunar distances Relative speed
2047-08-26 20:17:00 Juptr 0.3985 AU 155.1 LD 3.6 km/s
2047-08-26 20:17:00 Jupiter 0.3985 AU 155.1 LD 3.6 km/s
2106-11-22 18:15:00 Juptr 1.1387 AU 443.1 LD 5 km/s
2130-08-05 20:00:00 Juptr 1.0149 AU 395.0 LD 4.6 km/s
2193-09-12 08:39:00 Juptr 1.4564 AU 566.8 LD 2.7 km/s

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

Sources