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Comet

LINEAR

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239P/LINEAR

Where is it now

Distance from Sun
4.928 AU
True anomaly
223.95°
Distance from Earth
4.358 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 LINEAR — 4.928 AU from the Sun LINEAR
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. LINEAR is 4.358 AU from Earth today (36.2 light-minutes).

In the sky

Right ascension
21h 50m 21s
Declination
+00° 26′ 14″
Constellation
Aquarius
Distance from Earth
4.36 AU
Elongation from the Sun
119.12° — 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
4.47 AU
Eccentricity
0.6314
Inclination
11.31°
Orbital period
9.45 years
Perihelion
1.648 AU
Aphelion
7.293 AU
Longitude of ascending node
255.94°
Argument of periapsis
220.38°
Epoch · J2000
2457665.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 265.2 LD
0.6814 AU
Tisserand (Jupiter)
2.574

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
365
Data arc
19.43 years
First observed
14 November 1999
Last observed
19 April 2019
Residual RMS
0.46 ″
Solution · Otto Matic
15 April 2021

Visual & observation

Absolute magnitude (H)
15.3
Total magnitude M₁ · K₁ 13.3
15.3

Discovery & classification

Also known as 239P · 239P/1999 XB69 · 239P/2010 C2

Named

Close approaches 12 on record

When (UTC) Body Distance Lunar distances Relative speed
2031-09-13 12:55:00 Juptr 1.7543 AU 682.7 LD 6.5 km/s
2045-07-10 19:58:00 Juptr 1.3887 AU 540.5 LD 10.9 km/s
2067-02-13 17:47:00 Juptr 1.2703 AU 494.4 LD 12.2 km/s
2114-04-20 22:26:00 Jupiter 0.1573 AU 61.2 LD 9.8 km/s
2114-04-20 22:26:00 Juptr 0.1573 AU 61.2 LD 9.8 km/s
2126-01-18 06:37:00 Juptr 0.6198 AU 241.2 LD 7.5 km/s
2164-07-07 03:24:00 Juptr 1.8945 AU 737.3 LD 5.9 km/s
2176-08-08 09:21:00 Juptr 0.8297 AU 322.9 LD 9.8 km/s

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

Sources