Orbit of NEA (66391) 1999 KW4
Orbital elements listed here are taken from the JPL Horizons website, and represent the current best solution. The orbit will only be perturbed slightly during the close approach to the Earth, but we still provide the Keplerian elements for both the pre- and post-Earth encounter.
Orbital Elements (Solution JPL#265)
| Pre-Earth Encounter | Post-Earth Encounter | |
| Epoch | 2458619.5 (2019-May-16.0) | 2458639.5 (2019-Jun-05.0) |
| Perihelion Time | T = 2019-Mar-22 10:46:42 UT | T = 2019-Mar-22 10:31:19 UT |
| Perihelion Time (JD) | T = 2458564.949101 | T = 2458564.938410 |
| Orbital Period | P = 0.515 yr | P = 0.515 yr |
| Semi-major Axis | a = 0.6422 AU | a = 0.6423 AU |
| Perihelion Distance | q = 0.1999 AU | q = 0.2001 AU |
| Eccentricity | e = 0.6887 | e = 0.6885 |
| Inclination (J2000) | i = 38.88° | i = 38.89° |
| Ascending Node (J2000) | Ω = 244.91° | Ω = 244.91° |
| Argument of Perihelion (J2000) | ω = 192.62° | ω = 192.63° |
| Perigee Time | t = 2019-May-25 23:04 UT | |
| Perigee Distance | Δ = 0.034640 AU Δ = 5.1800×106 km |
|
| Velocity with respect to Earth at closest approach |
21.17 km/s | |
| Min. Orbital Intersection Dist. | MOID = 0.013085 AU | |
Full Orbit From Above
View of (66391) 1999 KW4's pre-encounter orbit as seen from the North ecliptic pole with the asteroid and planets shown at the time of the asteroid's closest approach to Earth. From the JPL Small-Body Database Browser.
Orbit in Oblique View
Oblique view of the portion of (66391) 1999 KW4's orbit around perigee, viewed from 30° above the ecliptic plane. The black dot denotes the asteroid's and Earth's positions at perigee (2019-May-25).
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Orbit in Earth Co-Orbital View
The orbit of (66391) 1999 KW4 around perihelion, in the Earth's co-orbital reference frame, as seen from above (top panel) and in the ecliptic plane (bottom panel). The black circle denotes the asteroid's position at perihelion (2019-Mar-22) and the open circles show positions at 30-day intervals.
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