(20002) Tillysmith Main-belt Asteroid
Discovered on 10 March 1991 by R. H. McNaught at Siding Spring.
Tilly Smith (b. 1994), in recognizing the signs of a tsunami and alerting beachgoers, saved many lives on the island of Phuket in the 2004 Dec. 26 tsunami disaster.Naming citation (WGSBN Bull. 4, #9, 6), IAU / Minor Planet Center, via NASA/JPL
Where Tillysmith is today
Seen from above the solar system on 2026-10-14: Tillysmith is 2.80 au from the Sun and 3.29 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 20002 |
| Provisional designation | 1991 EM |
| Orbit class | Main-belt Asteroid |
| Diameter | 11.7 km (#4,216 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.0510 |
| Rotation period | 10.8 hours |
| Absolute magnitude (H) | 13.61 |
| Orbital period | 5.69 years |
| Semi-major axis | 3.19 au |
| Perihelion – aphelion | 2.73 – 3.65 au |
| Eccentricity | 0.145 |
| Inclination | 20.2° |
| Closest distance between its orbit and Earth's (MOID) | 1.72 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.