Skip Page Navigation
NASA JPL Caltech
NASA Logo - Jet Propulsion Laboratory + View the NASA Portal
+ Center for Near-Earth Object Studies
JPL Home Earth Solar System Stars & Galaxies Technology
JPL Solar System Dynamics
BODIES ORBITS EPHEMERIDES TOOLS PHYSICAL DATA DISCOVERY FAQ SITE MAP
JPL Small-Body Database Browser
Search: [ help ]  
238P/Read (2005 U1)
Classification: Encke-type Comet          SPK-ID: 1001676
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ]

[ hide orbit diagram ]

For accurate long-term ephemerides, please instead use our Horizons system.This orbit viewer was implemented using two-body methods, and hence should not be used for determining accurate long-term trajectories (over several years or decades) or planetary encounter circumstances.


Orbital Elements at Epoch 2454616.5 (2008-May-30.0) TDB
Reference: JPL 18 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .2531969888951213 5.469e-07  
a 3.161984948654287 4.0958e-07 au
q 2.361379880723327 1.9414e-06 au
i 1.266167215096398 2.4294e-05 deg
node 51.62720266047121 0.00043601 deg
peri 325.6244378511225 0.00045372 deg
M 181.8403079775316 8.2564e-05 deg
tp 2455632.854178155310
(2011-Mar-12.35417816)
0.00061836 TDB
period 2053.70530214976
5.62
0.00039903
1.092e-06
d
yr
n .1752929203733185 3.4059e-08 deg/d
Q 3.962590016585248 5.1328e-07 au

Additional Model Parameters
 Parameter Value Uncertainty (1-sigma) 
A1 [EST] 2.436992850134412E-9 1.078E-9
A2 [EST] -5.277191806895388E-11 6.433E-11
  Orbit Determination Parameters
   # obs. used (total)      214  
   data-arc span      4407 days (12.07 yr)  
   first obs. used      2005-10-23  
   last obs. used      2017-11-16  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      1  
   norm. resid. RMS      .70522  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Apr-15 23:28:01  

Additional Information
 Earth MOID = 1.36176 au 
 Jupiter MOID = 1.4998 au 
 T_jup = 3.154 
[ hide covariance matrix ]
Orbit Covariance (8×8)
  e q tp node peri i A1 A2
e 2.991040323519506E-13 -1.054090819719845E-12 -1.792061938312838E-10 1.420985410852683E-12 -3.758009705514196E-11 -6.018067495518953E-13 4.128527359901805E-16 1.522153710749235E-17
q -1.054090819719845E-12 3.769111596749447E-12 7.211643783154705E-10 -3.033220054153502E-12 1.3769834608848E-10 1.944062786869974E-12 -1.567700102215819E-15 -6.67813793425706E-17
tp -1.792061938312838E-10 7.211643783154705E-10 3.823666765405551E-7 -5.152372645557471E-11 6.882720230191243E-8 1.413250704388243E-10 -3.316382226445451E-13 -3.379489683039622E-14
node 1.420985410852683E-12 -3.033220054153502E-12 -5.152372645557471E-11 1.90102212431387E-7 -1.903946213786086E-7 -3.113901155004143E-9 -1.566957522021546E-15 -2.966175340737453E-16
peri -3.758009705514196E-11 1.3769834608848E-10 6.882720230191243E-8 -1.903946213786086E-7 2.058616489479107E-7 3.181709697583604E-9 -3.522835424095458E-14 -4.087366834440533E-15
i -6.018067495518953E-13 1.944062786869974E-12 1.413250704388243E-10 -3.113901155004143E-9 3.181709697583604E-9 5.901834256176063E-10 -4.16957663963072E-16 1.020767488814359E-17
A1 4.128527359901805E-16 -1.567700102215819E-15 -3.316382226445451E-13 -1.566957522021546E-15 -3.522835424095458E-14 -4.16957663963072E-16 1.162056765179047E-18 4.222394518764492E-20
A2 1.522153710749235E-17 -6.67813793425706E-17 -3.379489683039622E-14 -2.966175340737453E-16 -4.087366834440533E-15 1.020767488814359E-17 4.222394518764492E-20 4.138401283152168E-21

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
comet total magnitude M1 10.1   0.7 18 2 parameter fit from 111 observations, autocmod 2.9c
comet total magnitude slope K1 24.   n/a 18 autocmod 2.9c
comet nuclear magnitude M2 17.6   01. 18 from 78 observations, autocmod 2.9c
comet nuclear magnitude slope K2 5.   n/a 18 autocmod 2.9c
comet nuclear phase coefficient PC 0.03   n/a 18 autocmod 2.9c

[ hide close-approach data ]
Close-Approach Data   ...sorted by Date/Time (TDB)
Date/Time (TDB) Time Uncertainty
(days_HH:MM)
Body Nominal Distance (au) Minimum Distance (au) Maximum Distance (au) V-relative (km/s) V-infinity (km/s) JD (TDB) Time Uncertainty (minutes) Semi-major axis (km) Semi-minor axis (km) range-LOV angle (deg) N-sigma BP Orbit Ref. Reference Modified
1923-Nov-14 20:20 11:50 Jupiter 1.82100453401411 1.82067113588172 1.82133777235369 1.89814157540999 1.63482749325167 2423738.347432274 710.475055306614 13215.9041504313 376.788595001415 -4.99876604563903 4253.48511890699 T 18 CATAB v2.0g-lin.ifort 2021-Apr-15 23:28:02 2021-Apr-15 23:28
1945-Oct-10 09:20 05:42 Jupiter 1.5363531912628 1.53633725942463 1.53636912326655 0.877178590803 n/a 2431738.889227963 342.46740076532 15307.8948468795 793.384547590583 89.8450876883663 289598.063065682 F 18 CATAB v2.0g-lin.ifort 2021-Apr-15 23:28:02 2021-Apr-15 23:28
1956-Sep-30 07:57 03:49 Jupiter 1.6665513584185 1.66647781324186 1.66662512067669 1.29948765762841 0.819860251906495 2435746.830982742 228.814696636145 62612.9089872801 4705.48831970332 -46.0538590037577 58371.8019861718 T 18 CATAB v2.0g-lin.ifort 2021-Apr-15 23:28:02 2021-Apr-15 23:28
1967-Aug-15 04:59 02:19 Jupiter 1.93212045962608 1.93205142606516 1.93218949100252 2.47513583072809 2.29118247852304 2439717.707742952 139.484952014921 3117.91098650599 1058.89707404683 85.3896059460671 27945.152686657 T 18 CATAB v2.0g-lin.ifort 2021-Apr-15 23:28:02 2021-Apr-15 23:28
2054-Aug-15 15:55 03:08 Jupiter 1.81356801706068 1.81342650621027 1.81370949880618 1.91611016057058 1.65450386346014 2471495.162924815 187.520235335965 5615.64205797447 157.706000722213 -1.61288191549419 7030.1241913022 T 18 CATAB v2.0g-lin.ifort 2021-Apr-15 23:28:02 2021-Apr-15 23:28
2065-Jul-10 15:40 04:45 Jupiter 1.58889487159319 1.58879010379323 1.5889996523709 1.02641258532591 n/a 2475477.152467007 285.289749984929 9007.71995276223 1140.83769063701 55.2065271145384 171699.91433227 F 18 CATAB v2.0g-lin.ifort 2021-Apr-15 23:28:02 2021-Apr-15 23:28
2076-Jul-09 07:42 07:08 Jupiter 1.53658580334106 1.53651303872556 1.53665868322902 0.867800470419949 n/a 2479493.820668560 427.883865899829 21331.8415823085 205.620635561318 -80.2141417818093 1101319.14156185 F 18 CATAB v2.0g-lin.ifort 2021-Apr-15 23:28:02 2021-Apr-15 23:28
2087-Jun-29 14:49 10:57 Jupiter 1.67116129434315 1.67080706543595 1.67151925954979 1.29086816936931 0.8078659057889 2483501.117399472 656.984195876603 256867.939234183 3187.12183196953 -44.2003437674479 98838.7997412726 T 18 CATAB v2.0g-lin.ifort 2021-Apr-15 23:28:02 2021-Apr-15 23:28
2098-May-14 12:26 14:41 Jupiter 1.93920895739329 1.93864170833051 1.93977613070943 2.45242151833005 2.26733235679741 2487473.018397563 880.498104880739 27434.7526850541 1068.68950943719 74.2409340822085 21792.398929465 T 18 CATAB v2.0g-lin.ifort 2021-Apr-15 23:28:02 2021-Apr-15 23:28
2185-May-09 12:57 1_13:04 Jupiter 1.79509337295048 1.79385799449902 1.79632635976112 1.89672602098428 1.629067529687 2519244.039716221 2224.04201869082 57596.7368401209 1335.06203383131 -0.12967936165611 777.401447296319 T 18 CATAB v2.0g-lin.ifort 2021-Apr-15 23:28:02 2021-Apr-15 23:28
2196-Apr-03 05:50 1_15:05 Jupiter 1.57813175781729 1.57744186345481 1.57882228097113 1.00844548719739 n/a 2523225.743336084 2345.2902246023 60677.6984005532 3752.4929634941 55.6028971304166 51940.5867124312 F 18 CATAB v2.0g-lin.ifort 2021-Apr-15 23:28:02 2021-Apr-15 23:28

Alternate Designations
 Perihelion 
Year
(est.)
 New-Style 
Desig
Roman
 Numeral 
Year/
 Letter 
 2011.2   238P/2010 N2       
 2005.6   238P/2005 U1       
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Close-Approach Data ]
ABOUT SSD CREDITS/AWARDS PRIVACY/COPYRIGHT GLOSSARY LINKS
FirstGov 2021-Jul-24 02:56 UT
(server date/time)  
NASA Home Page
Site Manager:   Ryan S. Park
Webmaster  Alan B. Chamberlin