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Comet

Lemmon

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423P/Lemmon

Where is it now

Distance from Sun
6.584 AU
True anomaly
130.65°
Distance from Earth
7.418 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 Lemmon — 6.584 AU from the Sun Lemmon
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Lemmon is 7.418 AU from Earth today (1.0 light-hours).

In the sky

Right ascension
15h 48m 24s
Declination
-23° 56′ 36″
Constellation
Scorpius
Distance from Earth
7.43 AU
Elongation from the Sun
30.13° — near the Sun — look low at dusk or dawn

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
6.158 AU
Eccentricity
0.1201
Inclination
8.35°
Orbital period
15.28 years
Perihelion
5.419 AU
Aphelion
6.897 AU
Longitude of ascending node
33.35°
Argument of periapsis
80.71°
Epoch · J2000
2458898.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 1,730.8 LD
4.4474 AU
Tisserand (Jupiter)
2.982

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
96
Data arc
15.13 years
First observed
8 February 2008
Last observed
27 March 2023
Residual RMS
0.41 ″
Solution · Otto Matic
28 March 2023

Visual & observation

Absolute magnitude (H)
13.8
Total magnitude M₁ · K₁ 4.5
13.8

Discovery & classification

Also known as 423P · 423P/2008 CL94 · 423P/2021 A12

Named

Close approaches 8 on record

When (UTC) Body Distance Lunar distances Relative speed
2043-05-26 01:44:00 Juptr 1.5877 AU 617.9 LD 2.1 km/s
2103-10-27 02:40:00 Juptr 1.6296 AU 634.2 LD 2.3 km/s
2162-07-29 02:11:00 Juptr 1.7693 AU 688.6 LD 2.4 km/s

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

Sources