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Asteroid

Dione

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106 Dione (A868 TA)

Where is it now

Distance from Sun
2.728 AU
True anomaly
329.78°
Distance from Earth
1.885 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 Dione — 2.728 AU from the Sun Dione
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Dione is 1.885 AU from Earth today (15.7 light-minutes).

In the sky

Right ascension
23h 33m 07s
Declination
-09° 01′ 51″
Constellation
Aquarius
Distance from Earth
1.89 AU
Elongation from the Sun
140.08° — 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
3.182 AU
Eccentricity
0.1587
Inclination
4.57°
Orbital period
5.68 years
Perihelion
2.677 AU
Aphelion
3.687 AU
Longitude of ascending node
61.98°
Argument of periapsis
331.77°
Epoch · J2000
2461200.5
Orbit class · MBA
Main-belt asteroid
Earth MOID · 655.2 LD
1.6835 AU
Tisserand (Jupiter)
3.174

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
10,152
Data arc
154.7 years
First observed
16 March 1871
Last observed
12 November 2025
Residual RMS
0.28 ″
Solution · Otto Matic
19 November 2025

Physical properties

Mean radius
104 km
Rotation period
16.21 hours

Visual & observation

Geometric albedo
0.044
Absolute magnitude (H)
7.76
Colour index (B–V)
0.74
Spectral type (SMASS)
Cgh
Spectral type (Tholen)
G
Colour index (U–B)
0.46

Discovery & classification

Discovered by
Watson, J. C.
Discovery date
10 October 1868
Discovery site
Ann Arbor

Also known as 106 · A868 TA · A902 TA

Main-Belt Asteroid Named

Close approaches 12 on record

When (UTC) Body Distance Lunar distances Relative speed
2030-05-10 10:58:00 Juptr 1.7352 AU 675.3 LD 2 km/s
2041-02-27 17:16:00 Juptr 1.7971 AU 699.4 LD 2 km/s
2051-12-10 22:57:00 Juptr 1.9727 AU 767.7 LD 2.6 km/s
2127-06-23 05:30:00 Juptr 1.9702 AU 766.7 LD 3.3 km/s
2138-03-19 10:39:00 Juptr 1.7918 AU 697.3 LD 2.3 km/s
2148-12-29 14:12:00 Juptr 1.7263 AU 671.8 LD 1.9 km/s
2159-10-19 04:31:00 Juptr 1.816 AU 706.7 LD 2.1 km/s

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

Sources