(196256) 2003 EH1 is an asteroid, classified as near-Earth object of the Amor group. It was discovered on 6 March 2003, by astronomers of the LONEOS program at Anderson Mesa Station near Flagstaff, Arizona, in the United States.[2][4] Peter Jenniskens (2003–2004) proposed that it is the parent body of the Quadrantid meteor shower.[5][6] 2003 EH1 is likely an extinct comet and may even be related to the comet C/1490 Y1. 2003 EH1 came to perihelion on 12 March 2014.[1]

| Discovery[1][2] | |
|---|---|
| Discovered by | LONEOS |
| Discovery date | 6 March 2003 |
| Designations | |
MPC designation | (196256) 2003 EH1 |
Minor planet category | NEO · Amor[1] extinct comet |
| Orbital characteristics[1] | |
| Epoch 13 January 2016 (JD 2457400.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 4035 days (11.05 yr) |
| Aphelion | 5.055446 AU (756.2840 Gm) (Q) |
| Perihelion | 1.190060 AU (178.0304 Gm) (q) |
Semi-major axis | 3.12275 AU (467.157 Gm) (a) |
| Eccentricity | 0.618907 (e) |
Orbital period (sidereal) | 5.52 yr (2015.6 d) |
Mean anomaly | 119.8736° (M) |
Mean motion | 0° 10m 42.984s / day (n) |
| Inclination | 70.865968° (i) |
Longitude of ascending node | 282.972499° (Ω) |
Argument of perihelion | 171.3709° (ω) |
| Earth MOID | 0.21143 AU (31.629 Gm) |
| Jupiter MOID | 0.231939 AU (34.6976 Gm) |
| TJupiter | 2.065 |
| Physical characteristics | |
| Dimensions | 2.6–4.0 km† |
Sidereal rotation period | 12.650±0.033 h[3] |
Absolute magnitude (H) | 16.2[1] |
†Assuming an albedo between 0.04 (typical of extinct comet nuclei) and 0.09.
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