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
IMPORTANT: The SSD Announcement email list is now available. Major changes are coming in the near future, including possible hostname and/or URL changes. To be notified of such changes, subscribe to this email list.

Please visit this page for more details.


JPL Small-Body Database Browser
Search: [ help ]  
78P/Gehrels 2
Classification: Jupiter-family Comet          SPK-ID: 1000030
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

[ show orbit diagram ]
:
Orbital Elements at Epoch 2456729.5 (2014-Mar-13.0) TDB
Reference: JPL K192/5 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .4619470353743215 1.9389e-07  
a 3.735867254747169 4.2854e-07 au
q 2.010094451864709 9.4926e-07 au
i 6.254021454418187 6.2276e-06 deg
node 210.5611153184889 0.00014064 deg
peri 192.7547414922277 0.0001462 deg
M 107.9019198213718 1.4563e-05 deg
tp 2455938.981109850876
(2012-Jan-12.48110985)
9.6313e-05 TDB
period 2637.458174282804
7.22
0.00045382
1.242e-06
d
yr
n .1364950555463856 2.3486e-08 deg/d
Q 5.461640057629629 6.2651e-07 au

Additional Model Parameters
 Parameter Value Uncertainty (1-sigma) 
A1 [EST] 1.586577280354216E-10 1.263E-10
A2 [EST] 3.809412379492953E-10 1.197E-11
A3 [EST] -2.53181412767283E-10 5.772E-11
ALN [SET] .0408373333128795 n/a
NK [SET] 2.6 n/a
NM [SET] 2. n/a
NN [SET] 3. n/a
R0 [SET] 5. n/a
  Orbit Determination Parameters
   # obs. used (total)      4900  
   data-arc span      3171 days (8.68 yr)  
   first obs. used      2011-05-03  
   last obs. used      2020-01-07  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .59664  
   source      ORB  
   producer      Javier Roa  
   solution date      2020-Jan-13 10:57:45  

Additional Information
 Earth MOID = 1.0198 au 
 Jupiter MOID = .0201683 au 
 T_jup = 2.887 
 Nongrav. accels. using CO driven g(r) 
[ show covariance matrix ]

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

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
comet total magnitude M1 8.2   0.9 K192/5 2 parameter fit from 1236 observations, autocmod 2.8
comet total magnitude slope K1 15.5   n/a K192/5 autocmod 2.8
comet nuclear magnitude M2 12.6   0.7 K192/5 from 3468 observations, autocmod 2.8
comet nuclear magnitude slope K2 5.   n/a K192/5 autocmod 2.8
comet nuclear phase coefficient PC 0.03   n/a K192/5 autocmod 2.8

78P/Gehrels 2          Discovered 1973-Sep-29 by Gehrels, Tom
discovered on plate/photo taken on discovery date as well as 9/30, 10/4
Reference: comet.disLast Updated: 2003-08-29

[ show close-approach data ]
Alternate Designations
 Perihelion 
Year
(est.)
 New-Style 
Desig
Roman
 Numeral 
Year/
 Letter 
 1990.4       1989 XVII   1989n 
 1983.1   78P/1981 L1   1981 XVII   1981f 
 1975.9   78P/1973 S1   1973 XI   1973n 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
ABOUT SSD CREDITS/AWARDS PRIVACY/COPYRIGHT GLOSSARY LINKS
FirstGov 2020-Jan-27 18:49 UT
(server date/time)  
NASA Home Page
Site Manager:   Ryan S. Park
Webmaster  Alan B. Chamberlin