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Solar
Moon

Deimos

Orbits Mars Wikipedia ↗

Where is it now

Distance from Sun
1.56 AU
True anomaly
109.78°
Distance from Earth
1.641 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 Mars — 1.56 AU from the Sun Mars
Deimos is shown at its parent, Mars. Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Mars is 1.641 AU from Earth today (13.6 light-minutes).

In the sky

Right ascension
08h 20m 16s
Declination
+20° 37′ 04″
Constellation
Cancer
Distance from Earth
1.64 AU
Elongation from the Sun
67.67° — well clear of the Sun

Favours the northern hemisphere; low or below the horizon from far south.

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
0.0003
Inclination
0.93°
Orbital period
30.3 hours
Perihelion
0 AU
Aphelion
0 AU
Longitude of ascending node
54.3°
Argument of periapsis
0°
Epoch · J2000
J2000

Physical properties

Mean radius
6.20 km
Mass
1.476 × 10¹⁵ kg
Density
1.471 g/cm³
Rotation period
30.31 hours
Axial tilt
0.9°
GM
0 km³/s²

Visual & observation

Geometric albedo
0.068
Representative colour
#9A8D80

Discovery & classification

Discovered by
Asaph Hall
Discovery date
12 August 1877

Sources