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Asteroid

Massalia

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20 Massalia (A852 SA)

Where is it now

Distance from Sun
2.594 AU
True anomaly
129.16°
Distance from Earth
3.467 AU
As of
11 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 — 0.998 AU from the Sun Earth Massalia — 2.594 AU from the Sun Massalia
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Massalia is 3.467 AU from Earth today (28.8 light-minutes).

In the sky

Right ascension
14h 43m 59s
Declination
-15° 37′ 41″
Constellation
Libra
Distance from Earth
3.47 AU
Elongation from the Sun
24.25° — near the Sun — look low at dusk or dawn

Favours the southern hemisphere; low or below the horizon from far north.

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
2.408 AU
Eccentricity
0.1436
Inclination
0.71°
Orbital period
3.74 years
Perihelion
2.062 AU
Aphelion
2.754 AU
Longitude of ascending node
205.95°
Argument of periapsis
257.2°
Epoch · J2000
2461200.5
Orbit class · MBA
Main-belt asteroid
Earth MOID · 419.8 LD
1.0788 AU
Tisserand (Jupiter)
3.507

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
10,321
Data arc
169.4 years
First observed
29 October 1856
Last observed
7 April 2026
Residual RMS
0.33 ″
Solution · Otto Matic
5 June 2026

Physical properties

Mean radius
68 km
Rotation period
8.1 hours

Visual & observation

Geometric albedo
0.241
Absolute magnitude (H)
6.54
Colour index (B–V)
0.85
Spectral type (SMASS)
S
Spectral type (Tholen)
S
Colour index (U–B)
0.46

Discovery & classification

Discovered by
de Gasparis, A.
Discovery date
19 September 1852
Discovery site
Naples

Also known as 20 · A852 SA

Main-Belt Asteroid Named

Sources