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Trans-Neptunian object

2005 PL21

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(2005 PL21)

Where is it now

Distance from Sun
45.811 AU
True anomaly
93.29°
Distance from Earth
45.148 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 2005 PL21 — 45.811 AU from the Sun 2005 PL21
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 2005 PL21 is 45.148 AU from Earth today (6.3 light-hours).

In the sky

Right ascension
23h 02m 25s
Declination
-10° 24′ 49″
Constellation
Aquarius
Distance from Earth
45.15 AU
Elongation from the Sun
131.03° — 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
46.426 AU
Eccentricity
0.1469
Inclination
4.74°
Orbital period
316.3 years
Perihelion
39.606 AU
Aphelion
53.245 AU
Longitude of ascending node
38.53°
Argument of periapsis
211.75°
Epoch · J2000
2461200.5
Orbit class · TNO
Trans-Neptunian object
Earth MOID · 15,019.4 LD
38.5933 AU
Tisserand (Jupiter)
6.001

Orbit quality

Orbit reasonably well determined (uncertainty code 5).

Observations used
13
Data arc
18.08 years
First observed
8 August 2005
Last observed
6 September 2023
Residual RMS
0.21 ″
Solution · Otto Matic
20 October 2023

Physical properties

Rotation period
4 hours

Visual & observation

Absolute magnitude (H)
6.74

Discovery & classification

TNO

Sources