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Comet

LINEAR

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251P/LINEAR

Where is it now

Distance from Sun
5.171 AU
True anomaly
168.85°
Distance from Earth
4.453 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 LINEAR — 5.171 AU from the Sun LINEAR
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. LINEAR is 4.453 AU from Earth today (37.0 light-minutes).

In the sky

Right ascension
04h 22m 54s
Declination
+12° 24′ 16″
Constellation
Taurus
Distance from Earth
4.45 AU
Elongation from the Sun
132.29° — 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
3.492 AU
Eccentricity
0.5098
Inclination
23.51°
Orbital period
6.53 years
Perihelion
1.712 AU
Aphelion
5.272 AU
Longitude of ascending node
219.55°
Argument of periapsis
30.91°
Epoch · J2000
2454201.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 285.2 LD
0.7328 AU
Tisserand (Jupiter)
2.783

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
431
Data arc
20.39 years
First observed
17 April 2004
Last observed
6 September 2024
Residual RMS
0.76 ″
Solution · Otto Matic
5 October 2024

Visual & observation

Absolute magnitude (H)
12
Total magnitude M₁ · K₁ 24.8
12

Discovery & classification

Also known as 251P · 251P/2004 HC18 · 251P/2011 J1

Named

Close approaches 12 on record

When (UTC) Body Distance Lunar distances Relative speed
2059-11-27 18:14:00 Juptr 0.9618 AU 374.3 LD 6.4 km/s
2071-07-10 19:45:00 Juptr 1.0707 AU 416.7 LD 9.6 km/s
2119-10-27 09:48:00 Juptr 1.677 AU 652.6 LD 7.7 km/s
2130-09-15 12:31:00 Juptr 0.2847 AU 110.8 LD 7.7 km/s
2130-09-15 12:31:00 Jupiter 0.2847 AU 110.8 LD 7.7 km/s
2167-07-20 21:23:00 Juptr 1.4673 AU 571.0 LD 6.6 km/s
2178-06-08 08:47:00 Juptr 1.8248 AU 710.2 LD 11.9 km/s

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

Sources