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Asteroid

Alexandra

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54 Alexandra (A858 RA)

Where is it now

Distance from Sun
2.898 AU
True anomaly
239.26°
Distance from Earth
3.783 AU
As of
21 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 Alexandra — 2.898 AU from the Sun Alexandra
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Alexandra is 3.783 AU from Earth today (31.5 light-minutes).

In the sky

Right ascension
12h 11m 06s
Declination
-08° 14′ 28″
Constellation
Virgo
Distance from Earth
3.78 AU
Elongation from the Sun
23.69° — near the Sun — look low at dusk or dawn

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
2.71 AU
Eccentricity
0.1992
Inclination
11.84°
Orbital period
4.46 years
Perihelion
2.17 AU
Aphelion
3.25 AU
Longitude of ascending node
313.01°
Argument of periapsis
346.36°
Epoch · J2000
2461200.5
Orbit class · MBA
Main-belt asteroid
Earth MOID · 450.0 LD
1.1563 AU
Tisserand (Jupiter)
3.304

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
10,913
Data arc
29.88 years
First observed
23 May 1996
Last observed
9 April 2026
Residual RMS
0.26 ″
Solution · Otto Matic
5 June 2026

Physical properties

Mean radius
80 km
Rotation period
7.02 hours

Visual & observation

Geometric albedo
0.059
Absolute magnitude (H)
7.94
Colour index (B–V)
0.73
Spectral type (SMASS)
C
Spectral type (Tholen)
C
Colour index (U–B)
0.36

Discovery & classification

Discovered by
Goldschmidt, H.
Discovery date
10 September 1858
Discovery site
Paris

Also known as 54 · A858 RA · 1950 BT · 1974 HG1

Main-Belt Asteroid Named

Close approaches 2 on record

When (UTC) Body Distance Lunar distances Relative speed
2132-09-21 12:33:00 Juptr 1.9969 AU 777.1 LD 3.5 km/s
2168-07-01 22:44:00 Juptr 1.994 AU 776.0 LD 3.5 km/s

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

Sources