Skip Page Navigation
NASA JPL Caltech
NASA Logo - Jet Propulsion Laboratory + View the NASA Portal
+ Near-Earth Object (NEO) Program
Search JPL
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 ]  
121P/Shoemaker-Holt 2
Classification: Jupiter-family Comet          SPK-ID: 1000141
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

[ hide orbit diagram ]
Orbit Diagram
Note: Make sure you have Java enabled on your browser to see the applet. This applet is provided as a 3D orbit visualization tool. The applet was implemented using 2-body methods, and hence should not be used for determining accurate long-term trajectories (over several years or decades) or planetary encounter circumstances. For accurate long-term ephemerides, please instead use our Horizons system.

Note: If the applet has stopped working because of a recent Java upgrade, here is a possible workaround.
Orbit Viewer

Additional Notes: the orbits shown in the applet are color coded. The planets are white lines, and the asteroid/comet is a blue line. The bright white line indicates the portion of the orbit that is above the ecliptic plane, and the darker portion is below the ecliptic plane. Likewise for the asteroid/comet orbit, the light blue indicates the portion above the ecliptic plane, and the dark blue the portion below the ecliptic plane.

Orbit Viewer applet originally written and kindly provided by Osamu Ajiki (AstroArts), and further modified by Ron Baalke (JPL).


Orbital Elements at Epoch 2456799.5 (2014-May-22.0) TDB
Reference: JPL 39 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1850207770465562 4.7955e-07  
a 4.606111568633298 1.2209e-06 AU
q 3.753885227041634 3.1634e-06 AU
i 20.15632999420141 2.1152e-05 deg
node 94.20597607904955 2.2434e-05 deg
peri 12.08068314388462 7.8425e-05 deg
M 25.81482683012296 5.6115e-05 deg
tp 2456540.579270503882
(2013-Sep-05.07927050)
0.00059417 JED
period 3610.772337617826
9.89
0.0014356
3.93e-06
d
yr
n .09970166112369927 3.9641e-08 deg/d
Q 5.458337910224962 1.4468e-06 AU
  Orbit Determination Parameters
   # obs. used (total)      557  
   data-arc span      9125 days (24.98 yr)  
   first obs. used      1989-03-04  
   last obs. used      2014-02-26  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-BIG16  
   condition code      1  
   fit RMS      .70499  
   data source      ORB  
   producer      Ryan S. Park  
   solution date      2014-May-12 10:53:54  

Additional Information
 Earth MOID = 2.77344 AU 
 T_jup = 2.866 
[ show covariance matrix ]

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

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
comet total magnitude M1 1.5 mag n/a ICQ 2005 Handbook  
comet total magnitude slope K1 25.0   n/a ICQ 2005 Handbook  
diameter diameter 3.24 km n/a Lamy,P.L.,Toth,I.,Fernandez,Y.R.,Weaver,H.A. (2004) Comets II, pp. 223-264  

121P/Shoemaker-Holt 2          Discovered 1989-Mar-09 by Shoemaker, Carolyn & Eugene, & Holt, Henry at Palomar Mountain Observatory, California (675)
discovered on plate/photo taken on discovery date
Reference: comet.disLast Updated: 2003-08-29

[ show close-approach data ]
Alternate Designations
 Perihelion 
Year
(est.)
 New-Style 
Desig
Roman
 Numeral 
Year/
 Letter 
 1993.9   121P/1995 Q3       1989j 
 1984.0       1988 XI   
Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
ABOUT SSD CREDITS/AWARDS PRIVACY/COPYRIGHT GLOSSARY LINKS
FirstGov 2014-Nov-21 16:22 UT
(server date/time)  
NASA Home Page
Site Manager:   Donald K. Yeomans
Webmaster  Alan B. Chamberlin