Encke (2P)

NEO ⇩ IMP ⇩ COV ★ EPH ⇩ OBS ⇩ Radar
Orbital Elements
Epoch (TDB)2022-10-03 (JD 2459855.5)
Eccentricity (e)0.8477003353 ± 2.19e-07
Semi-major axis (a)2.2196888070 AU ± 1.36e-07
Inclination (i)11.40704099° ± 2.08e-05
Long. of Asc. Node (Ω)334.18510998° ± 5.54e-05
Arg. of Perihelion (ω)187.14215822° ± 5.56e-05
Mean Anomaly (M)245.50091097° ± 1.14e-05
Mean Motion (n)0.2980340852°/day ± 2.73e-08
Perihelion dist (q)0.33805786 AU ± 4.86e-07
Aphelion dist (Q)4.10131975 AU ± 5.46e-07
Orbital Period3.30709248 yr ± 3.03e-07
Physical Parameters
Diameter4.800 km
Geometric Albedo0.046
Rotation Period11.083 h
Orbit Solution
SourceJPL
Solution Date2026-08-13 12:41:21
RMS Residual0.448″
Uncertainty1
Orbit TypeEncke-type Comet
MOID0.166917 AU
Observations Used645
Oppositions—
Arc Total2018-2026
First Observation Used—
Last Observation Used2026-08-11
Observations (6393)
Date Type RA Dec Mag Band Observatory
2005-09-09 21:18:37 C 22 42 58.57 -06 01 09.3 – c 213
2005-09-12 23:10:20 C 22 40 02.52 -06 16 43.7 – o 204
2005-09-12 23:46:20 C 22 40 01.09 -06 16 51.4 – o 204
2005-09-13 04:35:45 C 22 39 49.81 -06 17 51.3 – c 691
2005-09-13 05:00:51 C 22 39 48.79 -06 17 56.5 – c 691
2005-09-13 05:25:57 C 22 39 47.80 -06 18 01.8 – c 691
2005-09-22 04:27:48 C 22 31 38.75 -07 01 18.2 – o 644
2005-09-22 05:00:16 C 22 31 37.55 -07 01 24.9 – o 644
2005-09-22 05:30:44 C 22 31 36.43 -07 01 30.8 – o 644
2005-09-25 19:37:22 C 22 28 33.86 -07 17 39.8 – r 215
2005-09-30 03:57:53 C 22 25 05.52 -07 36 04.0 – r G96
2005-09-30 04:06:35 C 22 25 05.23 -07 36 05.7 – r G96
2005-09-30 04:15:04 C 22 25 04.94 -07 36 07.4 – r G96
2005-09-30 04:23:26 C 22 25 04.69 -07 36 08.8 – r G96
2005-10-07 02:52:48 C 22 20 06.71 -08 02 26.2 – c 691
2005-10-07 03:11:13 C 22 20 06.18 -08 02 28.7 – c 691
2005-10-07 03:29:46 C 22 20 05.71 -08 02 31.3 – c 691
2006-07-20 01:06:58 C 00 53 05.89 +11 33 35.1 – o 204
2006-08-15 01:45:52 C 00 48 59.65 +12 36 21.0 – o 204
2006-08-15 02:00:16 C 00 48 59.32 +12 36 21.5 – o 204
2006-08-21 23:45:10 C 00 45 02.19 +12 38 43.6 – c 213
2006-08-22 00:11:37 C 00 45 01.45 +12 38 43.4 – c 213
2006-08-22 00:16:44 C 00 45 01.30 +12 38 43.4 – c 213
2006-08-22 00:20:09 C 00 45 01.21 +12 38 43.4 – c 213
2006-08-24 23:01:40 C 00 42 55.02 +12 37 21.1 – r A02
2006-08-24 23:22:28 C 00 42 54.37 +12 37 20.6 – r A02
2006-08-24 23:42:12 C 00 42 53.78 +12 37 19.5 – r A02
2006-08-29 07:27:21 C 00 39 20.66 +12 32 34.1 – r 703
2006-08-29 07:35:54 C 00 39 20.34 +12 32 33.2 – r 703
2006-08-29 07:44:26 C 00 39 20.01 +12 32 33.0 – r 703
2006-08-29 07:53:00 C 00 39 19.72 +12 32 32.6 – r 703
2006-08-31 23:11:05 C 00 36 53.60 +12 27 54.1 – r 215
2006-09-01 22:55:05 C 00 35 55.69 +12 25 50.9 – c 213
2006-09-01 23:06:44 C 00 35 55.19 +12 25 49.7 – c 213
2006-09-01 23:19:34 C 00 35 54.69 +12 25 48.0 – c 213
2006-09-01 23:51:04 C 00 35 53.39 +12 25 45.3 – r 130
2006-09-01 23:55:23 C 00 35 53.24 +12 25 44.9 – r 130
2006-09-01 23:59:43 C 00 35 53.00 +12 25 44.0 – r 130
2006-09-02 00:04:02 C 00 35 52.86 +12 25 44.3 – r 130
2006-09-03 23:06:25 C 00 33 53.03 +12 21 01.4 – r 204
2006-09-06 09:20:13 C 00 31 15.55 +12 14 09.9 – o 644
2006-09-06 09:35:58 C 00 31 14.83 +12 14 08.0 – o 644
2006-09-06 09:58:39 C 00 31 13.73 +12 14 05.0 – o 644
2006-09-16 06:34:36 C 00 18 58.32 +11 33 33.1 – r 703
2006-09-16 06:44:28 C 00 18 57.74 +11 33 31.8 – r 703
2006-09-16 06:53:47 C 00 18 57.20 +11 33 29.3 – r 703
2006-09-16 07:03:06 C 00 18 56.66 +11 33 27.7 – r 703
2006-09-16 09:41:56 C 00 18 47.44 +11 32 52.1 – r 703
2006-09-16 09:50:49 C 00 18 46.87 +11 32 51.8 – r 703
2006-09-16 09:59:38 C 00 18 46.44 +11 32 49.5 – r 703
Radar Observations (2)
Epoch (UTC)ValueSigmaUnitsFreq (MHz)ReceiverTransmitter
1980-11-05 14:44:00 -280334.5 2.5 Hz 2380 -1 -1
1980-11-05.613889 -2803345 10 Hz 2380 251 251
Station codes
-1 Arecibo (305-m, 1963–2020)