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Comet

Leonard

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C/2021 G1 (Leonard)

Leonard is a comet in the Comet orbit class. Its orbit takes it from 3.42 AU to 148.41 AU from the Sun; one orbit takes 661.5 years. Orbit from the JPL solution of 14 January 2025.

Where is it now

Distance from Sun
13.918 AU
True anomaly
122.93°
Distance from Earth
13.173 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 Leonard — 13.918 AU from the Sun Leonard
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Leonard is 13.173 AU from Earth today (1.8 light-hours).

In the sky

Right ascension
04h 02m 09s
Declination
-17° 45′ 12″
Constellation
Eridanus
Distance from Earth
13.17 AU
Elongation from the Sun
137.44° — well clear of the Sun

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
75.916 AU
Eccentricity
0.9549
Inclination
131.57°
Orbital period
661.5 years
Perihelion
3.424 AU
Aphelion
148.409 AU
Longitude of ascending node
270.7°
Argument of periapsis
107.5°
Epoch · J2000
2459325.5
Orbit class · COM
Comet
Earth MOID · 1,084.4 LD
2.7864 AU
Tisserand (Jupiter)
-1.436

Orbit quality

Orbit poorly determined (uncertainty code 6).

Observations used
54
Data arc
41 days
First observed
11 April 2021
Last observed
22 May 2021
Residual RMS
0.48 ″
Solution · Otto Matic
14 January 2025

Visual & observation

Absolute magnitude (H)
13.7
Total magnitude M₁ · K₁ 10
13.7

Discovery & classification

Also known as 2021 G1

Named

Sources