Saturday, August 18, 2007

Jupiter Fact Sheet

Jupiter Fact Sheet

[Cassini image of Jupiter]

Jupiter/Earth Comparison

Bulk parameters

                                   Jupiter      Earth   Ratio (Jupiter/Earth)
Mass (1024 kg)                      1,898.6     5.9736      317.83
Volume (1010 km3)                 143,128     108.321      1321.33
Radius (1 bar level) (km)
   Equatorial                     71,492       6,378.1      11.209   
   Polar                          66,854       6,356.8      10.517
Volumetric mean radius (km)        69,911       6,371.0      10.973
Ellipticity                         0.06487     0.00335      19.36
Mean density (kg/m3)                1,326       5,515         0.240
Gravity (eq., 1 bar) (m/s2)        24.79        9.80          2.530
Acceleration (eq., 1 bar) (m/s2)   23.12        9.78          2.364
Escape velocity (km/s)             59.5        11.19          5.32
GM (x 106 km3/s2)                 126.686       0.3986      317.8
Bond albedo                         0.343       0.306         1.12
Visual geometric albedo             0.52        0.367         1.42 
Visual magnitude V(1,0)            -9.40       -3.86           -
Solar irradiance (W/m2)            50.50     1367.6           0.037
Black-body temperature (K)        110.0       254.3           0.433
Moment of inertia (I/MR2)           0.254       0.3308        0.768
J2 (x 10-6)                        14,736    1082.63         13.611   
Number of natural satellites       63           1
Planetary ring system             Yes          No

Orbital parameters

                                   Jupiter      Earth   Ratio (Jupiter/Earth)
Semimajor axis (106 km)             778.57      149.60        5.204  
Sidereal orbit period (days)      4,332.589     365.256      11.862  
Tropical orbit period (days)      4,330.595     365.242      11.857
Perihelion (106 km)                 740.52      147.09        5.034     
Aphelion (106 km)                   816.62      152.10        5.369
Synodic period (days)               398.88        -             -
Mean orbital velocity (km/s)         13.07       29.78        0.439   
Max. orbital velocity (km/s)         13.72       30.29        0.453       
Min. orbital velocity (km/s)         12.44       29.29        0.425      
Orbit inclination (deg)               1.304       0.000         -
Orbit eccentricity                    0.0489      0.0167      2.928
Sidereal rotation period (hours)      9.9250*    23.9345      0.415 
Length of day (hrs)                   9.9259     24.0000      0.414
Obliquity to orbit (deg)              3.13       23.45        0.133

* System III (1965.0) coordinates

Jupiter Observational Parameters

Discoverer:      Unknown
Discovery Date:  Prehistoric

Distance from Earth
       Minimum (106 km)          588.5
       Maximum (106 km)          968.1
Apparent diameter from Earth
       Maximum (seconds of arc)   49.0
       Minimum (seconds of arc)   29.8
Mean values at opposition from Earth
       Distance from Earth (106 km)        628.76   
       Apparent diameter (seconds of arc)   46.9
       Apparent visual magnitude            -2.7     
Maximum apparent visual magnitude            -2.94

Jupiter Mean Orbital Elements (J2000)

Semimajor axis (AU)                  5.20336301 
Orbital eccentricity                 0.04839266  
Orbital inclination (deg)            1.30530 
Longitude of ascending node (deg)  100.55615  
Longitude of perihelion (deg)       14.75385  
Mean Longitude (deg)                34.40438

North Pole of Rotation

Right Ascension: 268.05 - 0.009T
Declination    :  64.49 + 0.003T
Reference Date : 12:00 UT 1 Jan 2000 (JD 2451545.0)
T = Julian centuries from reference date

Jovian Magnetosphere

Goddard Space Flight Center O4 Model 
Dipole field strength: 4.28 gauss-Rj3
Dipole tilt to rotational axis: 9.6 degrees
Longitude of tilt: 201.7 degrees
Dipole offset (planet center to dipole center) distance: 0.131 Rj
Latitude/Longitude of offset vector: -8.0 degrees/148.57 degrees

Note: All latitudes/longitudes are given in Jovian System III (1965.0) coordinates.
Rj denotes Jovian radii, 71,398 km

Jovian Atmosphere

Surface Pressure: >>1000 bars 
Temperature at 1 bar: 165 K (-108 C)
Temperature at 0.1 bar: 112 K (-161 C)
Density at 1 bar: 0.16 kg/m3
Wind speeds
  Up to 150 m/s (<30 degrees latitude)
  Up to  40 m/s (>30 degrees latitude)
Scale height: 27 km
Mean molecular weight: 2.22 g/mole
Atmospheric composition (by volume, uncertainty in parentheses)
   Major:       Molecular hydrogen (H2) - 89.8% (2.0%); Helium (He) - 10.2% (2.0%)
   Minor (ppm): Methane (CH4) - 3000 (1000); Ammonia (NH3) - 260 (40);
                Hydrogen Deuteride (HD) - 28 (10); Ethane (C2H6) - 5.8 (1.5);
                Water (H2O) - 4 (varies with pressure)
   Aerosols:    Ammonia ice, water ice, ammonia hydrosulfide

http://nssdc.gsfc.nasa.gov/planetary/factsheet/jupiterfact.html
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Neptune Fact Sheet

Neptune Fact Sheet

[Image of Neptune]

Neptune/Earth Comparison

Bulk parameters

                                   Neptune      Earth   Ratio (Neptune/Earth)
Mass (1024 kg)                     102.43      5.9736        17.147
Volume (1010 km3)                    6,254   108.321         57.74
Radius (1 bar level) (km)
   Equatorial                     24,764      6,378.1        3.883
   Polar                          24,341      6,356.8        3.829
Volumetric mean radius (km)        24,624      6,371.0        3.865
Ellipticity (Flattening)            0.01708    0.00335        5.10
Mean density (kg/m3)                1,638      5,515          0.297
Gravity (eq., 1 bar) (m/s2)        11.15       9.80           1.14
Acceleration (eq., 1 bar) (m/s2)   11.00       9.78           1.12
Escape velocity (km/s)             23.5       11.19           2.10
GM (x 106 km3/s2)                   6.8351     0.3986        17.15
Bond albedo                         0.290      0.306          0.95
Visual geometric albedo             0.41       0.367          1.12
Visual magnitude V(1,0)            -6.87      -3.86             -
Solar irradiance (W/m2)             1.51       1,367.6        0.0011
Black-body temperature (K)         46.6      254.3            0.183
J2 (x 10-6)                      3411.      1082.63           3.151   
Number of natural satellites       13          1
Planetary ring system             Yes         No

Orbital parameters

                                   Neptune      Earth   Ratio (Neptune/Earth)
Semimajor axis (106 km)           4,495.06      149.60       30.047
Sidereal orbit period (days)     60,189.        365.256     164.79  
Tropical orbit period (days)     59,799.9       365.242     163.73
Perihelion (106 km)               4,444.45      147.09       30.216    
Aphelion (106 km)                 4,545.67      152.10       29.886
Synodic period (days)               367.49        -             -
Mean orbital velocity (km/s)          5.43      29.78         0.182  
Max. orbital velocity (km/s)          5.50      30.29         0.182      
Min. orbital velocity (km/s)          5.37      29.29         0.183     
Orbit inclination (deg)               1.769       0.000         -
Orbit eccentricity                    0.0113      0.0167      0.677
Sidereal rotation period (hours)     16.11*      23.9345      0.673
Length of day (hrs)                  16.11       24.0000      0.671
Obliquity to orbit (deg)             28.32       23.45        1.208

* Magnetic coordinates (as determined by the Voyager 2 Radio Science experiment)

Neptune Observational Parameters

Discoverer:      Johann Gottfried Galle  (based on predictions by 
                John Couch Adams and Urbain Leverrier)
Discovery Date:  23 September 1846

Distance from Earth
       Minimum (106 km)         4305.9
       Maximum (106 km)         4687.3
Apparent diameter from Earth
       Maximum (seconds of arc)    2.4
       Minimum (seconds of arc)    2.2
Mean values at opposition from Earth
       Distance from Earth (106 km)       4347.31   
       Apparent diameter (seconds of arc)    2.3
       Apparent visual magnitude             7.8     
Maximum apparent visual magnitude             7.78

Neptune Mean Orbital Elements (J2000)

Semimajor axis (AU)                 30.06896348 
Orbital eccentricity                 0.00858587  
Orbital inclination (deg)            1.76917 
Longitude of ascending node (deg)  131.72169  
Longitude of perihelion (deg)       44.97135 
Mean Longitude (deg)               304.88003

North Pole of Rotation

Right Ascension: 299.36 + 0.70 sin N
Declination    :  43.46 - 0.51 cos N
Reference Date : 12:00 UT 1 Jan 2000 (JD 2451545.0)
N = 359.28 + 549.308T degrees
T = Julian centuries from reference date

Neptunian Magnetosphere

Goddard Space Flight Center OTD (O8) Model 
Dipole field strength: 0.142 gauss-Rn3
Dipole tilt to rotational axis: 46.9 degrees
Longitude of tilt: 288 degrees (IAU convention)
Dipole offset (planet center to dipole center) distance: 0.55 Rn

Note: Rn denotes Neptunian radii, here defined to be 24,765 km

Neptunian Atmosphere

Surface Pressure: >>1000 bars 
Temperature at 1 bar: 72 K (-201 C)
Temperature at 0.1 bar: 55 K (-218 C)
Density at 1 bar: 0.45 kg/m3
Wind speeds: 0-200 m/s
Scale height: 19.1 - 20.3 km
Mean molecular weight: 2.53 - 2.69 g/mole
Atmospheric composition (by volume, uncertainty in parentheses)
   Major:       Molecular hydrogen (H2) - 80.0% (3.2%); Helium (He) - 19.0% (3.2%);
                Methane (CH4) 1.5% (0.5%)
   Minor (ppm): Hydrogen Deuteride (HD) - 192; Ethane (C2H6) - 1.5
   Aerosols:    Ammonia ice, water ice, ammonia hydrosulfide, methane ice(?)


http://nssdc.gsfc.nasa.gov/planetary/factsheet/neptunefact.html
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Saturn Fact Sheet

Saturn Fact Sheet

[Voyager 2 image of Saturn]

Saturn/Earth Comparison

Bulk parameters

                                     Saturn      Earth   Ratio (Saturn/Earth)
Mass (1024 kg)                      568.46       5.9736       95.159
Volume (1010 km3)                    82,713    108.321       763.59
Radius (1 bar level) (km)
   Equatorial                       60,268      6,378.1       9.449  
   Polar                            54,364      6,356.8       8.552
Volumetric mean radius (km)          58,232      6,371.0       9.140
Ellipticity (Flattening)              0.09796    0.00335      29.24
Mean density (kg/m3)                    687      5,515         0.125
Gravity (eq., 1 bar) (m/s2)          10.44       9.80          1.065
Acceleration (eq., 1 bar) (m/s2)      8.96       9.78          0.916
Escape velocity (km/s)               35.5       11.19          3.172
GM (x 106 km3/s2)                    37.931      0.3986       95.16
Bond albedo                           0.342      0.306         1.12
Visual geometric albedo               0.47       0.367         1.28
Visual magnitude V(1,0)              -8.88      -3.86            -
Solar irradiance (W/m2)              14.90       1,367.6       0.011
Black-body temperature (K)           81.1      254.3           0.319
Moment of inertia (I/MR2)             0.210      0.3308        0.635
J2 (x 10-6)                      16,298.      1082.63         15.054   
Number of natural satellites         56          1
Planetary ring system               Yes         No

Orbital parameters

                                     Saturn      Earth   Ratio (Saturn/Earth)
Semimajor axis (106 km)            1,433.53      149.60        9.582
Sidereal orbit period (days)      10,759.22      365.256      29.457  
Tropical orbit period (days)      10,746.94      365.242      29.424
Perihelion (106 km)                1,352.55      147.09        9.195     
Aphelion (106 km)                  1,514.50      152.10        9.957
Synodic period (days)                378.09        -             -
Mean orbital velocity (km/s)           9.69       29.78        0.325   
Max. orbital velocity (km/s)          10.18       30.29        0.336       
Min. orbital velocity (km/s)           9.09       29.29        0.310      
Orbit inclination (deg)                2.485       0.000         -
Orbit eccentricity                     0.0565      0.0167      3.383
Sidereal rotation period (hours)      10.656*     23.9345      0.445
Length of day (hrs)                   10.656      24.0000      0.444
Obliquity to orbit (deg)              26.73       23.45        1.140

* Saturnian System III coordinates

Saturn Observational Parameters

Discoverer:      Unknown
Discovery Date:  Prehistoric

Distance from Earth
       Minimum (106 km)         1195.5
       Maximum (106 km)         1658.5
Apparent diameter from Earth
       Maximum (seconds of arc)   20.1
       Minimum (seconds of arc)   14.5
Mean values at opposition from Earth
       Distance from Earth (106 km)       1277.42   
       Apparent diameter (seconds of arc)   19.5
       Apparent visual magnitude             0.7
Maximum apparent visual magnitude             0.43

Saturn Mean Orbital Elements (J2000)

Semimajor axis (AU)                  9.53707032 
Orbital eccentricity                 0.05415060  
Orbital inclination (deg)            2.48446  
Longitude of ascending node (deg)  113.71504  
Longitude of perihelion (deg)       92.43194  
Mean Longitude (deg)                49.94432

North Pole of Rotation

Right Ascension: 40.5954 - 0.0577T
Declination    : 83.5380 - 0.0066T
Reference Date : 12:00 UT 1 Jan 2000 (JD 2451545.0)
T = Julian centuries from reference date

Saturnian Magnetosphere

Dipole field strength: 0.210 gauss-Rs3
Dipole tilt to rotational axis: < 1 degree
Dipole offset (planet center to dipole center) distance: 0.04 to 0.05 Rs northward

Note: Saturn's magnetic field has significant quadrapole and octapole moments, making approximation of the central field as an offset dipole difficult.
Rs denotes Saturnian radii, 60,330 km

Saturnian Atmosphere

Surface Pressure: >>1000 bars 
Temperature at 1 bar: 134 K (-139 C)
Temperature at 0.1 bar: 84 K (-189 C)
Density at 1 bar: 0.19 kg/m3
Wind speeds
  Up to 400 m/s (<30 degrees latitude)
  Up to 150 m/s (>30 degrees latitude)
Scale height: 59.5 km
Mean molecular weight: 2.07 g/mole
Atmospheric composition (by volume, uncertainty in parentheses)
   Major:       Molecular hydrogen (H2) - 96.3% (2.4%); Helium (He) - 3.25% (2.4%)
   Minor (ppm): Methane (CH4) - 4500 (2000); Ammonia (NH3) - 125 (75);
                Hydrogen Deuteride (HD) - 110 (58); Ethane (C2H6) - 7 (1.5)
   Aerosols:    Ammonia ice, water ice, ammonia hydrosulfide


http://nssdc.gsfc.nasa.gov/planetary/factsheet/saturnfact.html
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Uranus Fact Sheet

Uranus Fact Sheet

[Voyager 2 image of Uranus]

Uranus/Earth Comparison

Bulk parameters

                                    Uranus      Earth   Ratio (Uranus/Earth)
Mass (1024 kg)                      86.832      5.9736        14.536
Volume (1010 km3)                    6,833    108.321         63.08
Radius (1 bar level) (km)
   Equatorial                      25,559      6,378.1        4.007
   Polar                           24,973      6,356.8        3.929
Volumetric mean radius (km)         25,362      6,371.0        3.981
Ellipticity (Flattening)             0.02293    0.00335        6.84
Mean density (kg/m3)                 1,270      5,515          0.230
Gravity (eq., 1 bar) (m/s2)          8.87       9.80           0.905
Acceleration (eq., 1 bar) (m/s2)     8.69       9.78           0.889
Escape velocity (km/s)              21.3       11.19           1.903
GM (x 106 km3/s2)                    5.794      0.3986        14.536
Bond albedo                          0.300      0.306          0.980
Visual geometric albedo              0.51       0.367          1.390
Visual magnitude V(1,0)             -7.19      -3.86             -
Solar irradiance (W/m2)              3.71       1,367.6        0.0027
Black-body temperature (K)          58.2      254.3            0.229
Moment of inertia (I/MR2)            0.225      0.3308         0.680
J2 (x 10-6)                       3343.43    1082.63           3.088   
Number of natural satellites        27          1
Planetary ring system              Yes         No

Orbital parameters

                                    Uranus      Earth   Ratio (Uranus/Earth)
Semimajor axis (106 km)            2,872.46      149.60       19.201
Sidereal orbit period (days)      30,685.4       365.256      84.011  
Tropical orbit period (days)      30,588.740     365.242      83.749
Perihelion (106 km)                2,741.30      147.09       18.637    
Aphelion (106 km)                  3,003.62      152.10       19.748
Synodic period (days)                369.66        -             -
Mean orbital velocity (km/s)           6.81       29.78        0.229   
Max. orbital velocity (km/s)           7.11       30.29        0.235       
Min. orbital velocity (km/s)           6.49       29.29        0.222      
Orbit inclination (deg)                0.772       0.000         -
Orbit eccentricity                     0.0457      0.0167      2.737
Sidereal rotation period (hours)     -17.24*      23.9345      0.720
Length of day (hrs)                   17.24       24.0000      0.718
Obliquity to orbit (deg)              97.77       23.45        4.169

* Magnetic coordinates (as determined by the Voyager 2 Radio Science experiment)

Uranus Observational Parameters

Discoverer:      William Herschel
Discovery Date:  13 March 1781

Distance from Earth
       Minimum (106 km)         2581.9
       Maximum (106 km)         3157.3
Apparent diameter from Earth
       Maximum (seconds of arc)    4.1
       Minimum (seconds of arc)    3.3
Mean values at opposition from Earth
       Distance from Earth (106 km)       2719.99   
       Apparent diameter (seconds of arc)    3.9
       Apparent visual magnitude             5.5 
Maximum apparent visual magnitude             5.32

Uranus Mean Orbital Elements (J2000)

Semimajor axis (AU)                 19.19126393 
Orbital eccentricity                 0.04716771  
Orbital inclination (deg)            0.76986  
Longitude of ascending node (deg)   74.22988 
Longitude of perihelion (deg)      170.96424 
Mean Longitude (deg)               313.23218

North Pole of Rotation

Right Ascension: 257.43
Declination    : -15.10
Reference Date : 12:00 UT 1 Jan 2000 (JD 2451545.0)

Uranian Magnetosphere

Dipole field strength: 0.228 gauss-Ru3
Dipole tilt to rotational axis: 58.6 degrees
Dipole offset (planet center to dipole center) distance: 0.3 Ru along the rotation axis

Note: Ru denotes Uranian radii, here defined to be 25,600 km

Uranian Atmosphere

Surface Pressure: >>1000 bars 
Temperature at 1 bar: 76 K (-197 C)
Temperature at 0.1 bar: 53 K (-220 C)
Density at 1 bar: 0.42 kg/m3
Wind speeds: 0-200 m/s
Scale height: 27.7 km
Mean molecular weight: 2.64 g/mole
Atmospheric composition (by volume, uncertainty in parentheses)
   Major:       Molecular hydrogen (H2) - 82.5% (3.3%); Helium (He) - 15.2% (3.3%)
                Methane (CH4) - 2.3%
   Minor (ppm): Hydrogen Deuteride (HD) - 148
   Aerosols:    Ammonia ice, water ice, ammonia hydrosulfide, methane ice(?)

http://nssdc.gsfc.nasa.gov/planetary/factsheet/uranusfact.html
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Pluto Fact Sheet

Pluto Fact Sheet

[Hubble image of Pluto and Charon]

Pluto/Earth Comparison

Bulk parameters

                                  Pluto          Earth      Ratio (Pluto/Earth)
Mass (1024 kg)                    0.0125         5.9736         0.0021
Volume (1010 km3)                 0.715        108.321          0.0066
Equatorial radius (km)            1195           6378.1        0.187
Polar radius (km)                  1195           6356.8        0.188
Volumetric mean radius (km)        1195           6371.0        0.188        
Ellipticity (Flattening)          0.0000         0.00335        0.0
Mean density (kg/m3)               1750           5515          0.317
Surface gravity (m/s2)            0.58           9.80           0.059
Surface acceleration (m/s2)       0.58           9.78           0.059
Escape velocity (km/s)            1.2           11.19           0.107
GM (x 106 km3/s2)                 0.00083        0.3986         0.0021 
Bond albedo                    0.4 - 0.6         0.306        1.3 - 2.0
Visual geometric albedo        0.5 - 0.7         0.367        1.4 - 1.9
Visual magnitude V(1,0)          -1.0           -3.86             -
Solar irradiance (W/m2)           0.89           1367.6         0.0007
Black-body temperature (K)       37.5          254.3            0.147
Number of natural satellites      3*             1
Planetary ring system            No             No

* The two newly discovered moons of Pluto have been named
Nix and Hydra.

Orbital parameters

                                  Pluto           Earth      Ratio (Pluto/Earth)
Semimajor axis (106 km)         5906.38          149.60          39.482
Sidereal orbit period (days)     90,465          365.256        247.68
Tropical orbit period (days)     90,588          365.242        248.02
Perihelion (106 km)             4436.82          147.09          30.164      
Aphelion (106 km)               7375.93          152.10          48.494
Synodic period (days)            366.73             -              -
Mean orbital velocity (km/s)       4.72           29.78           0.158
Max. orbital velocity (km/s)       6.10           30.29           0.201    
Min. orbital velocity (km/s)       3.71           29.29           0.127   
Orbit inclination (deg)           17.16            0.000           -
Orbit eccentricity                 0.2488          0.0167        14.899
Sidereal rotation period (hrs)  -153.2928         23.9345         6.405
Length of day (hrs)              153.2820         24.0000         6.387
Obliquity to orbit (deg)         122.53           23.45          (2.451)

Pluto Observational Parameters

Discoverer:      Clyde Tombaugh
Discovery Date:  18 February 1930

Distance from Earth
       Minimum (106 km)         4284.7
       Maximum (106 km)         7528.0
Apparent diameter from Earth
       Maximum (seconds of arc)    0.11
       Minimum (seconds of arc)    0.06
Mean values at opposition from Earth
       Distance from Earth (106 km)       5750.54   
       Apparent diameter (seconds of arc)    0.08
       Apparent visual magnitude            15.1     
Maximum apparent visual magnitude            13.65

Pluto Mean Orbital Elements (J2000)

Semimajor axis (AU)                 39.48168677 
Orbital eccentricity                 0.24880766 
Orbital inclination (deg)           17.14175 
Longitude of ascending node (deg)  110.30347 
Longitude of perihelion (deg)      224.06676 
Mean longitude (deg)               238.92881

On 11 February 1999 at 11:22 UT (6:22 a.m. EST), Pluto passed Neptune as the
furthest planet from the Sun once again and will remain so until 5 April 2231.

North Pole of Rotation

Right Ascension: 313.02
Declination    :   9.09
Reference Date : 12:00 UT 1 Jan 2000 (JD 2451545.0)

Pluto Atmosphere

Surface Pressure: ~3 microbar
Average temperature: ~50 K (-223 C)
Scale height: ~60 km
Mean molecular weight: ~16-25 g/mole
Atmospheric composition:  Methane (CH4), Nitrogen (N2)

Charon

Mean distance from Pluto (km)     19,600       
Sidereal orbit period (days)        6.38725       
Sidereal rotation period (days)     6.38725       
Orbital inclination to Pluto (deg)  0.0      
Orbital eccentricity                0.0
Equatorial radius (km)              593         
Mass (1021 kg)                      1.62       
Mean density (kg/m3)               1850
Surface gravity (m/s2)              0.31
Escape velocity (km/s)              0.60 
Geometric albedo                    0.38
Apparent visual magnitude          16.8

http://nssdc.gsfc.nasa.gov/planetary/factsheet/plutofact.html
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Comet Fact Sheet

Comet Fact Sheet

[Image of Halley nucleus]

Information on Selected Comets

The image shown is a view of the nucleus of Comet Halley taken by the Giotto spacecraft. Below is a table of information on selected comets, and at the bottom of the page are comments on the comets. 

                         Orbital   Perihelion   Perihelion   Semi-Major     Orbital        Orbital     Absolute
 Number & Name           Period       Date       Distance       Axis      Eccentricity   Inclination   Magnitude
 -------------           -------   ----------   ----------   ----------   ------------   -----------   ---------
 1P Halley             76.1 yrs.  1986-02-09    0.587 AU     17.94 AU        0.967       162.2 deg.      5.5                                                                                       
 2P Encke               3.30 yrs. 2003-12-28    0.340 AU      2.21 AU        0.847        11.8 deg.      9.8                                                                                            
 6P d'Arrest            6.51 yrs. 2008-08-01    1.346 AU      3.49 AU        0.614        19.5 deg.      8.5  
 9P Tempel 1            5.51 yrs. 2005-07-05    1.500 AU      3.12 AU        0.519        10.5 deg.     12.0
19P Borrelly            6.86 yrs. 2001-09-14    1.358 AU      3.61 AU        0.624        30.3 deg.     11.9
21P Giacobini-Zinner    6.52 yrs. 1998-11-21    0.996 AU      3.52 AU        0.706        31.8 deg.      9.0                         
26P Grigg-Skjellerup    5.09 yrs. 1992-07-22    0.989 AU      2.96 AU        0.664        21.1 deg.     12.5                                                                                                      
27P Crommelin          27.89 yrs. 1984-09-01    0.743 AU      9.20 AU        0.919        29.0 deg.     12.0                                                                               
45P Honda-Mrkos         
       -Pajdusakova     5.29 yrs. 1995-12-25    0.528 AU      3.02 AU        0.825         4.3 deg.     13.5
46P Wirtanen            5.46 yrs. 2013-10-21    1.063 AU      3.12 AU        0.652        11.7 deg.      9.0                         
55P Tempel-Tuttle      32.92 yrs. 1998-02-28    0.982 AU     10.33 AU        0.906       162.5 deg.      9.0                                                                   
67P Churyumov
        -Gerasimenko    6.57 yrs. 2002-08-18    1.292 AU      3.51 AU        0.632         7.1 deg.
73P Schwassmann         5.36 yrs. 2006-06-02    0.937 AU      3.06 AU        0.694        11.4 deg.     11.7
       -Wachmann 3
75P Kohoutek            6.24 yrs. 1973-12-28    1.571 AU      3.4 AU         0.537         5.4 deg.     12.1   
76P West-Kohoutek
           -Ikemura     6.46 yrs. 2000-06-01    1.596 AU      3.45 AU        0.540        30.5 deg.     10.6
81P Wild 2              6.39 yrs. 2003-09-25    1.583 AU      3.44 AU        0.540         3.2 deg.      6.5                                       
95P Chiron             50.7 yrs.  1996-02-14    8.46 AU      13.7 AU         0.383         7 deg.    
107P Wilson-Harrington   4.29 yrs. 2001-03-26    1.000 AU      2.64 AU        0.623         2.8 deg.      9.0
    Hale-Bopp          4000. yrs. 1997-03-31    0.914 AU      250. AU        0.995        89.4 deg.     -1.0
    Hyakutake        ~40000. yrs. 1996-05-01    0.230 AU    ~1165. AU        0.9998      124.9 deg.
Halley - Subject of the International Halley Watch (IHW), a coordinated effort of ground-based and spacecraft observations.
Encke - Planned encounter by CONTOUR mission on 12 November 2003. Radar observations made by Arecibo Observatory in 1980 indicated a radius of 0.4 to 4.0 km.
d'Arrest - Planned encounter by CONTOUR mission on 16 August 2008.
Tempel 1 - Planned flyby and projectile impact by the Deep Impact mission on 4 July 2005.
Borrelly - Target of Deep Space 1 spacecraft in 2001.
Giacobini-Zinner - Target of ICE flyby on 11 Sep 1985 within 7800 km.
Grigg-Skjellerup - Target of Giotto flyby (within 200 km) on 10 July 1992.
Crommelin - Subject of 1984 test of the IHW network.
Honda-Mrkos-Pajdusakova - Originally planned target of Sakigake flyby at 10,000 km on 3 Feb 1996.
Wirtanen - Originally scheduled to be visited by the ESA Rosetta mission in 2011. Mission rerouted.
Temple-Tuttle - Originally planned target of Suisei flyby on 28 Feb 1998.
Churyumov-Gerasimenko - Planned target of Rosetta mission in Nov 2014.
Schwassmann-Wachmann 3 - Planned encounter by CONTOUR mission on 18 June 2006. Split into three large pieces in 1995.
Kohoutek - Observed by Skylab astronauts in Dec 1973 and Jan 1974.
West-Kohoutek-Ikemura - Original target of New Millenium Deep Space 1 spacecraft in 2000.
Wild 2 - Target of the Discovery coma sample return mission, Stardust , in Jan 2004.
Wilson-Harrington - At one time a possible target of Deep Space 1 spacecraft in 2001.
Chiron - Comet/asteroid, also known as asteroid 2060 Chiron. Subject of the Chiron Perihelion Campaign
Hale-Bopp - Discovered in July 1995. Bright comet, made closest approach to Earth on 22 March 1997.
Hyakutake - Discovered in January 1996. Bright comet, passed within 0.1 AU of Earth on 25 March 1996.

http://nssdc.gsfc.nasa.gov/planetary/factsheet/cometfact.html
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Chiron Fact Sheet

Chiron Fact Sheet

Information on Comet 95P/Chiron / Minor Planet (2060) Chiron

Perihelion Date: 14 February 1996, 18:06 UT
Perihelion Distance: 8.4639422 AU
Date of Perihelion Opposition: 01 April 1996 (closest approach to Earth)
Orbital Period: 50.7 years
Eccentricity: 0.3831118
Inclination: 6.93540 degrees
Semi-Major Axis: ~13.70354 AU
Aphelion: ~18.94314 AU
Mass: 2 x 1018 to 1019 kg
Diameter: 148 to 208 km
Rotation Period: ~5.9 hours
Asteroid Classification: B-type
Discoverer: Charles Kowal
Date of Discovery: 01 November 1977 (on a photographic plate taken 18 October)

Osculating Orbital Elements

B1950.0 reference frame, Epoch 2450100.5 (17 Jan 1996) Semi-Major Axis: 13.7053530 AU
Eccentricity: 0.3831649
Inclination: 6.93524 deg.
Longitude of Ascending Node: 208.65735 deg.
Longitude of Perihelion: 339.58061 deg.
Mean Anomaly: 359.46170 deg.

http://nssdc.gsfc.nasa.gov/planetary/factsheet/chironfact.html
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Moon Fact Sheet

Moon Fact Sheet

[Global view of Moon]

Moon/Earth Comparison

Bulk parameters

                                   Moon         Earth      Ratio (Moon/Earth)
Mass (1024 kg)                    0.07349       5.9736     0.0123   
Volume (1010 km3)                 2.1958      108.321      0.0203
Equatorial radius (km)            1738.1        6378.1    0.2725     
Polar radius (km)                  1736.0        6356.8    0.2731
Volumetric mean radius (km)        1737.1        6371.0    0.2727
Ellipticity (Flattening)          0.0012        0.00335    0.36   
Mean density (kg/m3)               3350          5515      0.607     
Surface gravity (m/s2)            1.62          9.80       0.165   
Surface acceleration (m/s2)       1.62          9.78       0.166   
Escape velocity (km/s)            2.38         11.2        0.213   
GM (x 106 km3/s2)                 0.0049        0.3986     0.0123
Bond albedo                       0.11          0.306      0.360
Visual geometric albedo           0.12          0.367      0.330   
Visual magnitude V(1,0)          +0.21         -3.86          -
Solar irradiance (W/m2)            1367.6        1367.6    1.000     
Black-body temperature (K)          274.5         254.3    1.079     
Topographic range (km)               16            20      0.800     
Moment of inertia (I/MR2)         0.394         0.3308     1.191
J2 (x 10-6)                     202.7        1082.63        0.187

Orbital parameters (for orbit about the Earth)

                                    Moon        
Semimajor axis (106 km)             0.3844                
Perigee (106 km)*                   0.3633
Apogee (106 km)*                    0.4055
Revolution period (days)           27.3217           
Synodic period (days)              29.53              
Mean orbital velocity (km/s)        1.023                 
Max. orbital velocity (km/s)        1.076
Min. orbital velocity (km/s)        0.964
Inclination to ecliptic (deg)       5.145
Inclination to equator (deg)       18.28 - 28.58                   
Orbit eccentricity                  0.0549             
Sidereal rotation period (hrs)    655.728               
Obliquity to orbit (deg)            6.68                  
Recession rate from Earth (cm/yr)   3.8

Mean values at opposition from Earth
       Distance from Earth (equator, km)   378,000   
       Apparent diameter (seconds of arc)     1896
       Apparent visual magnitude               -12.74    

* These represent mean apogee and perigee for the lunar orbit. 
The orbit changes over the course of the year so the distance
from the Moon to Earth roughly ranges from 357,000 km to 407,000 km.

Lunar Atmosphere

Diurnal temperature range: >100 K to <400 K  (roughly -250 F to +250 F)
Total mass of atmosphere:  ~25,000 kg
Surface pressure (night): 3 x 10-15 bar  (2 x 10-12 torr)
Abundance at surface: 2 x 105 particles/cm3

Estimated Composition (particles per cubic cm):
   Helium 4 (4He) - 40,000 ; Neon 20 (20Ne) - 40,000 ; Hydrogen (H2) - 35,000
   Argon 40 (40Ar) - 30,000 ; Neon 22 (22Ne) - 5,000 ; Argon 36 (36Ar) - 2,000
   Methane - 1000 ; Ammonia - 1000 ; Carbon Dioxide (CO2) - 1000
   Trace Oxygen (O+), Aluminum (Al+), Silicon (Si+)
   Possible Phosphorus (P+), Sodium (Na+), Magnesium (Mg+)

Composition of the tenuous lunar atmosphere is poorly known and variable,
these are estimates of the upper limits of the nighttime ambient atmosphere
composition.  Daytime levels were difficult to measure due to heating and
outgassing of Apollo surface experiments.
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Earth Fact Sheet

Earth Fact Sheet

[Global view of Earth]

Bulk parameters

Mass (1024 kg)                 5.9736
Volume (1010 km3)             108.321  
Equatorial radius (km)         6378.1   
Polar radius (km)               6356.8        
Volumetric mean radius (km)     6371.0
Core radius (km)                3485
Ellipticity (Flattening)        0.00335     
Mean density (kg/m3)            5515     
Surface gravity (m/s2)          9.798 
Surface acceleration (m/s2)     9.780       
Escape velocity (km/s)         11.186
GM (x 106 km3/s2)               0.3986     
Bond albedo                     0.306 
Visual geometric albedo         0.367
Visual magnitude V(1,0)        -3.86
Solar irradiance (W/m2)         1367.6   
Black-body temperature (K)       254.3   
Topographic range (km)            20
Moment of inertia (I/MR2)       0.3308
J2 (x 10-6)                    1082.63     
Number of natural satellites       1         
Planetary ring system             No

Orbital parameters

Semimajor axis (106 km)         149.60   
Sidereal orbit period (days)    365.256
Tropical orbit period (days)    365.242   
Perihelion (106 km)             147.09       
Aphelion (106 km)               152.10
Mean orbital velocity (km/s)     29.78       
Max. orbital velocity (km/s)     30.29
Min. orbital velocity (km/s)     29.29
Orbit inclination (deg)           0.000    
Orbit eccentricity                0.0167    
Sidereal rotation period (hrs)   23.9345   
Length of day (hrs)              24.0000
Obliquity to orbit (deg)         23.45

Earth Mean Orbital Elements (J2000)

Semimajor axis (AU)                  1.00000011 
Orbital eccentricity                 0.01671022  
Orbital inclination (deg)            0.00005 
Longitude of ascending node (deg)  -11.26064 
Longitude of perihelion (deg)      102.94719 
Mean Longitude (deg)               100.46435

North Pole of Rotation

Right Ascension:  0.00 - 0.641T
Declination    : 90.00 - 0.557T
Reference Date : 12:00 UT 1 Jan 2000 (JD 2451545.0)
T = Julian centuries from reference date

Terrestrial Magnetosphere

Dipole field strength: 0.3076 gauss-Re3
Latitude/Longitude of dipole N: 78.6 degrees N/70.1 degrees W
Dipole offset (planet center to dipole center) distance: 0.0725 Re
Latitude/Longitude of offset vector: 18.3 degrees N/147.8 degrees E

Note: Re denotes Earth radii, 6,378 km

Terrestrial Atmosphere

Surface pressure: 1014 mb
Surface density: 1.217 kg/m3
Scale height: 8.5 km
Total mass of atmosphere:  5.1 x 1018 kg
Total mass of hydrosphere:  1.4 x 1021 kg
Average temperature:  288 K (15 C)
Diurnal temperature range: 283 K to 293 K (10 to 20 C)
Wind speeds: 0 to 100 m/s
Mean molecular weight: 28.97 g/mole
Atmospheric composition (by volume, dry air):
   Major      : 78.084% Nitrogen (N2), 20.946% Oxygen (O2),
   Minor (ppm): Argon (Ar) - 9340; Carbon Dioxide (CO2) - 380
                Neon (Ne) - 18.18; Helium (He) - 5.24; CH4 - 1.7
                Krypton (Kr) - 1.14; Hydrogen (H2) - 0.55
   Water is highly variable, typically makes up about 1%

source:http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html
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Open Source — Selling Software That Sells Itself

Open Source — Selling Software That Sells Itself


"Open source is changing not just how companies make software, but how they sell it. Alfresco's Matt Asay explains the new sales cycle and the skills that today's software sales people need to close deals. [...] 'But you know what? We have worked with Microsoft on interop without doing any sort of a patent deal; as has Sugar and MySQL and Zend and these other companies. We work directly with Microsoft for a customer of ours to insure SQL Server integration with Alfresco. Didn't have to sign any patent deal with them to get that done. We both had a mutual customer. It was in our mutual interest. We both wanted to make money, therefore we did it. But the patent thing is a complete smoke and mirrors, I don't want to say trick, but it has nothing to do with interoperability. No matter how much Microsoft may repeat that, it has nothing to do with interoperability.'"
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