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Comet

Larsen

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C/2004 C1 (Larsen)

Where is it now

Distance from Sun
18.236 AU
True anomaly
190.87°
Distance from Earth
18.246 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 Larsen — 18.236 AU from the Sun Larsen
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Larsen is 18.246 AU from Earth today (2.5 light-hours).

In the sky

Right ascension
19h 52m 34s
Declination
-05° 23′ 33″
Constellation
Aquila
Distance from Earth
18.25 AU
Elongation from the Sun
87.59° — 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
11.568 AU
Eccentricity
0.6232
Inclination
28.92°
Orbital period
39.35 years
Perihelion
4.359 AU
Aphelion
18.777 AU
Longitude of ascending node
151.95°
Argument of periapsis
316.15°
Epoch · J2000
2453061.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 1,339.2 LD
3.4411 AU
Tisserand (Jupiter)
2.491

Orbit quality

Orbit reasonably well determined (uncertainty code 5).

Observations used
94
Data arc
79 days
First observed
23 January 2004
Last observed
11 April 2004
Residual RMS
0.78 ″
Solution · Otto Matic
15 April 2021

Visual & observation

Absolute magnitude (H)
10
Total magnitude M₁ · K₁ 10
10

Discovery & classification

Also known as 2004 C1

Named

Sources