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Solar
Moon

Larissa

Orbits Neptune

Where is it now

Distance from Sun
29.889 AU
True anomaly
313.97°
Distance from Earth
28.898 AU
As of
2 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 — 1.001 AU from the Sun Earth Neptune — 29.889 AU from the Sun Neptune
Larissa is shown at its parent, Neptune. Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Neptune is 28.898 AU from Earth today (4.0 light-hours).

In the sky

Right ascension
00h 08m 51s
Declination
-00° 34′ 37″
Constellation
Pisces
Distance from Earth
28.9 AU
Elongation from the Sun
171.48° — near opposition — up most of the night

Visible from both hemispheres.

Shown at its parent's position — a moon sits within a fraction of a degree of its planet.

From your location

See how high it is right now, whether it's up after dark, 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
0 AU
Eccentricity
0.001
Inclination
0.2°
Orbital period
13.3 hours
Perihelion
0 AU
Aphelion
0 AU
Longitude of ascending node
312°
Argument of periapsis
247.3°
Epoch · Laplace
2000-01-01.5

Physical properties

Mean radius
96 km
Mass
3.818 × 10¹⁸ kg
Density
1.03 g/cm³
Axial tilt
0.4°
GM
0.255 km³/s²

Discovery & classification

Discovery date
1989

Sources