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Comet

PANSTARRS

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399P/PANSTARRS

Where is it now

Distance from Sun
4.661 AU
True anomaly
219.29°
Distance from Earth
5.075 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 PANSTARRS — 4.661 AU from the Sun PANSTARRS
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. PANSTARRS is 5.075 AU from Earth today (42.2 light-minutes).

In the sky

Right ascension
17h 55m 42s
Declination
-11° 46′ 24″
Constellation
Serpens
Distance from Earth
5.08 AU
Elongation from the Sun
59.87° — near the Sun — look low at dusk or dawn

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
3.811 AU
Eccentricity
0.442
Inclination
13.35°
Orbital period
7.44 years
Perihelion
2.127 AU
Aphelion
5.496 AU
Longitude of ascending node
207.56°
Argument of periapsis
213.32°
Epoch · J2000
2458086.5
Orbit class · JFc
Jupiter-family comet (P < 20 y)
Earth MOID · 448.1 LD
1.1514 AU
Tisserand (Jupiter)
2.859

Orbit quality

Orbit very well determined (uncertainty code 1).

Observations used
411
Data arc
23.3 years
First observed
16 November 1998
Last observed
7 March 2022
Residual RMS
0.63 ″
Solution · Otto Matic
9 June 2026

Visual & observation

Absolute magnitude (H)
15.9
Total magnitude M₁ · K₁ 4.5
15.9

Discovery & classification

Also known as 399P · 399P/2013 O2 · 399P/2020 O4

Named

Close approaches 13 on record

When (UTC) Body Distance Lunar distances Relative speed
2053-08-30 04:06:00 Jupiter 0.3088 AU 120.2 LD 5.5 km/s
2053-08-30 04:06:00 Juptr 0.3088 AU 120.2 LD 5.5 km/s
2113-02-10 06:10:00 Jupiter 0.4881 AU 189.9 LD 4 km/s
2113-02-10 06:10:00 Juptr 0.4881 AU 189.9 LD 4 km/s
2116-06-05 06:29:00 Juptr 1.8097 AU 704.3 LD 2.7 km/s
2136-06-11 12:23:00 Jupiter 0.3562 AU 138.6 LD 5.4 km/s
2136-06-11 12:23:00 Juptr 0.3562 AU 138.6 LD 5.4 km/s
2186-05-14 15:33:00 Juptr 1.5428 AU 600.4 LD 8.3 km/s

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

Sources