Where is it now
- Distance from Sun
- 1.503 AU
- True anomaly
- 115.54°
- Distance from Earth
- 0.959 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.
In the sky
- Right ascension
- 19h 54m 40s
- Declination
- -06° 57′ 04″
- Constellation
- Aquila
- Distance from Earth
- 0.97 AU
- Elongation from the Sun
- 100.08° — well clear of the Sun
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.
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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
- 1.431 AU
- Eccentricity
- 0.2562
- Inclination
- 8.71°
- Orbital period
- 625.3 days
- Perihelion
- 1.064 AU
- Aphelion
- 1.798 AU
- Longitude of ascending node
- 246.27°
- Argument of periapsis
- 338.49°
- Epoch · J2000
- 2461200.5
- Orbit class · AMO
- Amor
- Earth MOID · 24.3 LD
- 0.0626 AU
- Tisserand (Jupiter)
- 4.638
Orbit quality
Orbit very well determined (uncertainty code 0).
- Observations used
- 7,640
- Data arc
- 53.58 years
- First observed
- 10 March 1973
- Last observed
- 9 October 2026
- Residual RMS
- 0.38 ″
- Solution · Otto Matic
- 10 October 2026
Physical properties
- Mean radius
- 1.15 km
- Rotation period
- 2.87 hours
Visual & observation
- Geometric albedo
- 0.17
- Absolute magnitude (H)
- 15.66
- Colour index (B–V)
- 0.84
- Spectral type (SMASS)
- L
- Spectral type (Tholen)
- S
- Colour index (U–B)
- 0.44
Discovery & classification
- Discovered by
- Gibson, J.
- Discovery date
- 13 March 1973
- Discovery site
- El Leoncito
Also known as 1943 · 1973 EC
Close approaches 12 on record
Top-down view of the ecliptic, Earth at the centre, for the 2038-05-23 09:26 UTC close approach of Anteros. Catalogue miss distance 25.8 LD · 9.93 × 10⁶ km. The curve is the geocentric path from 2038-05-20 to 2038-05-26, with a mark at UTC midnights and an arrow for the direction of motion. The circle is the Moon’s mean orbit; the Moon is plotted at closest approach. A ray shows the Sun’s direction. The labelled distance is the full separation. The drawn radius is the part that lies in the ecliptic plane. The path is a geocentric ecliptic ephemeris from JPL Horizons. The Moon’s position is approximate. The inset is a heliocentric view and is approximate.
| When (UTC) | Body | Distance | Lunar distances | Relative speed |
|---|---|---|---|---|
| 2038-05-23 09:26:00 | Earth | 0.0664 AU | 25.8 LD | 5.8 km/s |
| 2050-05-20 09:34:00 | Earth | 0.0636 AU | 24.8 LD | 5.5 km/s |
| 2062-05-14 21:01:00 | Earth | 0.096 AU | 37.4 LD | 5.5 km/s |
| 2115-06-01 17:52:00 | Earth | 0.1396 AU | 54.3 LD | 7.5 km/s |
| 2127-05-24 21:51:00 | Earth | 0.0651 AU | 25.3 LD | 5.8 km/s |
| 2139-05-20 15:23:00 | Earth | 0.0684 AU | 26.6 LD | 5.4 km/s |
| 2151-05-10 11:54:00 | Earth | 0.1482 AU | 57.7 LD | 6.3 km/s |
Next ten from today. 1 lunar distance = 384,400 km. Source: JPL close-approach data.
Sources
- visual properties: JPL SBDB (lookup)
- physical properties: JPL SBDB (lookup)
- physical properties: JPL SBDB (lookup)
- visual properties: JPL SBDB (lookup)
- visual properties: JPL SBDB (lookup)
- visual properties: JPL SBDB (lookup)
- visual properties: JPL SBDB (lookup)
- visual properties: JPL SBDB (lookup)
- orbital elements: JPL SBDB