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Comet

Lemmon

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P/2021 TR81 (Lemmon)

Where is it now

Distance from Sun
11.077 AU
True anomaly
155.43°
Distance from Earth
11.381 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 Lemmon — 11.077 AU from the Sun Lemmon
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Lemmon is 11.381 AU from Earth today (1.6 light-hours).

In the sky

Right ascension
18h 24m 31s
Declination
+09° 18′ 32″
Constellation
Ophiuchus
Distance from Earth
11.38 AU
Elongation from the Sun
69.67° — 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
8.765 AU
Eccentricity
0.8325
Inclination
36.82°
Orbital period
25.95 years
Perihelion
1.469 AU
Aphelion
16.062 AU
Longitude of ascending node
220.21°
Argument of periapsis
272.04°
Epoch · J2000
2459581.5
Orbit class · HTC
Halley-type comet
Earth MOID · 337.9 LD
0.8683 AU
Tisserand (Jupiter)
1.745

Orbit quality

Orbit reasonably well determined (uncertainty code 4).

Observations used
118
Data arc
258 days
First observed
11 September 2021
Last observed
27 May 2022
Residual RMS
0.6 ″
Solution · Otto Matic
30 June 2025

Visual & observation

Absolute magnitude (H)
15.6
Total magnitude M₁ · K₁ 11
15.6

Discovery & classification

Also known as 2021 TR81

Named

Close approaches 3 on record

When (UTC) Body Distance Lunar distances Relative speed
2047-04-03 06:25:00 Juptr 1.5615 AU 607.7 LD 14.3 km/s
2102-03-28 11:14:00 Juptr 1.8191 AU 708.0 LD 17.1 km/s

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

Sources