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Asteroid Near-Earth

5131

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5131 (1990 BG)

Where is it now

Distance from Sun
1.067 AU
True anomaly
95.79°
Distance from Earth
0.864 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 5131 — 1.067 AU from the Sun 5131
Seen from above the ecliptic, north up, to scale. Grid: Earth's orbit in blue. 5131 is 0.864 AU from Earth today (7.2 light-minutes).

In the sky

Right ascension
17h 20m 53s
Declination
-58° 34′ 53″
Constellation
Ara
Distance from Earth
0.87 AU
Elongation from the Sun
69.69° — 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
1.486 AU
Eccentricity
0.5688
Inclination
36.45°
Orbital period
661.8 days
Perihelion
0.641 AU
Aphelion
2.331 AU
Longitude of ascending node
110.33°
Argument of periapsis
135.89°
Epoch · J2000
2461200.5
Orbit class · APO
Apollo
Earth MOID · 106.8 LD
0.2745 AU
Tisserand (Jupiter)
4.208

Orbit quality

Orbit very well determined (uncertainty code 0).

Observations used
2,893
Data arc
36.71 years
First observed
24 January 1990
Last observed
10 October 2026
Residual RMS
0.44 ″
Solution · Otto Matic
10 October 2026

Physical properties

Rotation period
37.2 hours

Visual & observation

Absolute magnitude (H)
14.82
Spectral type (SMASS)
S

Discovery & classification

Discovered by
Helin, E. F., Roman, B.
Discovery date
21 January 1990
Discovery site
Palomar

Also known as 1990 BG

Apollo Near-Earth Object

Close approaches 13 on record

When (UTC) Body Distance Lunar distances Relative speed
2028-06-26 13:47:00 Venus 0.029 AU 11.3 LD 25.3 km/s
2059-04-03 21:03:00 Venus 0.0415 AU 16.1 LD 27 km/s
2091-11-09 04:48:00 Venus 0.0066 AU 2.6 LD 26.1 km/s
2109-08-28 09:05:00 Mars 0.0936 AU 36.4 LD 20.3 km/s
2133-09-11 11:26:00 Venus 0.0457 AU 17.8 LD 27 km/s
2135-07-08 04:18:00 Venus 0.1404 AU 54.6 LD 23.5 km/s
2164-03-21 06:29:00 Mars 0.0924 AU 35.9 LD 18.2 km/s
2177-05-16 18:46:00 Venus 0.0403 AU 15.7 LD 26.9 km/s
2179-03-13 00:45:00 Venus 0.1355 AU 52.7 LD 23.6 km/s

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

Sources