(12857) Johandemessie Main-belt Asteroid
Discovered on 21 April 1998 by LINEAR at Socorro.
Johan DeMessie (b. 2005) was a finalist in the 2019 Broadcom MASTERS, a math and science competition for middle-school students, for his environmental and earth sciences project. He attended the Mason Middle School, Mason, Ohio.Naming citation (WGSBN Bull. 3, #1, 8), IAU / Minor Planet Center, via NASA/JPL
Where Johandemessie is today
Seen from above the solar system on 2026-10-14: Johandemessie is 3.09 au from the Sun and 3.73 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 12857 |
| Provisional designation | 1998 HQ97 |
| Orbit class | Main-belt Asteroid |
| Rotation period | 2.69 hours |
| Absolute magnitude (H) | 13.68 |
| Orbital period | 4.96 years |
| Semi-major axis | 2.91 au |
| Perihelion – aphelion | 2.69 – 3.13 au |
| Eccentricity | 0.0752 |
| Inclination | 2.02° |
| Closest distance between its orbit and Earth's (MOID) | 1.68 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
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