(3251) Eratosthenes Main-belt Asteroid

Discovered on 24 September 1960 by van Houten, C. J., van Houten-Groeneveld, I., Gehrels, T. at Palomar.

Named for the Greek scholar Erathosthenes, who lived in Alexandria around 250 B.C. and was the first person to determine the size of the earth correctly.Naming citation (WGSBN Bull. 4, #9, 4), IAU / Minor Planet Center, via NASA/JPL

Where Eratosthenes is today

Seen from above the solar system on 2026-10-14: Eratosthenes is 2.65 au from the Sun and 1.68 au from Earth. Computed from JPL's orbital elements.

Facts

Number	3251
Provisional designation	6536 P-L
Orbit class	Main-belt Asteroid
Diameter	15.0 km (#3,144 largest of 17,440 named asteroids with a measured size)
Albedo	0.0650
Absolute magnitude (H)	12.92
Orbital period	5.51 years
Semi-major axis	3.12 au
Perihelion – aphelion	2.65 – 3.59 au
Eccentricity	0.151
Inclination	0.725°
Closest distance between its orbit and Earth's (MOID)	1.65 au

Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.

Also discovered on 24 September 1960

More named asteroids discovered by van Houten, C. J., van Houten-Groeneveld, I., Gehrels, T.

All 958

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