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Asteroid Near-Earth

Zao

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5751 Zao (1992 AC)

Where is it now

Distance from Sun
2.817 AU
True anomaly
156.14°
Distance from Earth
2.739 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 Zao — 2.817 AU from the Sun Zao
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. Zao is 2.739 AU from Earth today (22.8 light-minutes).

In the sky

Right ascension
18h 55m 15s
Declination
-23° 19′ 02″
Constellation
Sagittarius
Distance from Earth
2.75 AU
Elongation from the Sun
83.58° — well clear of the Sun

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
2.102 AU
Eccentricity
0.4253
Inclination
16.07°
Orbital period
3.05 years
Perihelion
1.208 AU
Aphelion
2.996 AU
Longitude of ascending node
121.63°
Argument of periapsis
25.46°
Epoch · J2000
2461200.5
Orbit class · AMO
Amor
Earth MOID · 93.6 LD
0.2406 AU
Tisserand (Jupiter)
3.581

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
3,021
Data arc
37.36 years
First observed
10 March 1989
Last observed
19 July 2026
Residual RMS
0.5 ″
Solution · Otto Matic
20 July 2026

Physical properties

Mean radius
1.15 km
Rotation period
3.17 days

Visual & observation

Geometric albedo
0.36
Absolute magnitude (H)
14.94
Spectral type (SMASS)
X

Discovery & classification

Discovered by
Koishikawa, M.
Discovery date
5 January 1992
Discovery site
Ayashi

Also known as 5751 · 1992 AC · 1989 EN1

Amor Near-Earth Object Named

Sources