(18499) Showalter Mars-crossing Asteroid

Discovered on 22 June 1996 by NEAT at Haleakala.

Mark R. Showalter (b. 1957), planetary scientist at the SETI Institute, is (co-)discover of the Jovian gossamer ring, Saturnian moon Pan, Uranian moons Mab and Cupid, two faint Uranian rings, Neptunian moon S/2004 N 1, and Plutonian moons Kerberos and Styx. He is the leader of the Planetary Data Systems Rings Node.Naming citation (MPC batch dated 2014-09-09), IAU / Minor Planet Center, via NASA/JPL

Where Showalter is today

Seen from above the solar system on 2026-10-14: Showalter is 2.23 au from the Sun and 1.72 au from Earth. Computed from JPL's orbital elements.

Facts

Number	18499
Provisional designation	1996 MR
Orbit class	Mars-crossing Asteroid
Absolute magnitude (H)	15.98
Orbital period	3.70 years
Semi-major axis	2.39 au
Perihelion – aphelion	1.56 – 3.23 au
Eccentricity	0.349
Inclination	4.28°
Closest distance between its orbit and Earth's (MOID)	0.544 au

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

Also named after someone called Mark

All asteroids named after someone called Mark

Also discovered on 22 June 1996

(18498) Cesaro

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← (18498) Cesaro · (18501) Luria →