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Trans-Neptunian object

2005 PN21

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(2005 PN21)

Where is it now

Distance from Sun
45.739 AU
True anomaly
53.61°
Distance from Earth
44.814 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.

Sun Earth — 0.995 AU from the Sun Earth 2005 PN21 — 45.739 AU from the Sun 2005 PN21
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2005 PN21 is 44.814 AU from Earth today (6.2 light-hours).

In the sky

Right ascension
00h 29m 36s
Declination
+01° 58′ 58″
Constellation
Cetus
Distance from Earth
44.82 AU
Elongation from the Sun
157.59° — 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
45.741 AU
Eccentricity
0.0001
Inclination
2.72°
Orbital period
309.4 years
Perihelion
45.738 AU
Aphelion
45.744 AU
Longitude of ascending node
31.66°
Argument of periapsis
282.76°
Epoch · J2000
2453590.5
Orbit class · TNO
Trans-Neptunian object
Earth MOID · 17,404.8 LD
44.7227 AU
Tisserand (Jupiter)
6.037

Orbit quality

Orbit very uncertain — the object may be effectively lost (uncertainty code 9).

Observations used
3
Data arc
24 hours
First observed
8 August 2005
Last observed
9 August 2005
Residual RMS
0.04 ″
Solution · Otto Matic
14 April 2021

Visual & observation

Absolute magnitude (H)
6.33

Discovery & classification

TNO

Sources