Asteroid Fact Sheet

[Gaspra]

Information on Selected Asteroids

The image above is a false color view of the asteroid 951 Gaspra taken by the Galileo spacecraft. Below is a table of information on selected asteroids, and at the bottom of the page are comments on the asteroids. All of the values for mass and many of the diameter values are only rough estimates. 
   Asteroid          Diameter      ~Mass    Rotation    Orbital   Spectral   Semimajor     Orbital        Orbital       Number
Number and Name        (km)       1015 kg     Period     Period     Class       Axis      Eccentricity   Inclination    and Name
---------------      --------     -------   --------    -------   --------   ---------    ------------   -----------    -------- 
    1 Ceres         960 x 932     870,000   9.075 hrs   4.60 yrs      C       2.767 AU       0.0789       10.58 deg      1 Ceres
    2 Pallas     570 x 525 x 482  318,000   7.811 hrs   4.61 yrs      U       2.774 AU       0.2299       34.84 deg      2 Pallas
    3 Juno             240         20,000   7.210 hrs   4.36 yrs      S       2.669 AU       0.2579       12.97 deg      3 Juno
    4 Vesta            530        300,000   5.342 hrs   3.63 yrs      U       2.362 AU       0.0895        7.14 deg      4 Vesta 
   45 Eugenia          226          6,100   5.699 hrs   4.49 yrs     FC       2.721 AU       0.0831        6.61 deg     45 Eugenia
  140 Siwa             103          1,500  18.5   hrs   4.51 yrs      C       2.734 AU       0.2157        3.19 deg    140 Siwa
  216 Kleopatra     217 x 94                5.385 hrs   4.67 yrs      M       2.793 AU       0.2535       13.14 deg    216 Kleopatra
  243 Ida            58 x 23       100      4.633 hrs   4.84 yrs      S       2.861 AU       0.0451        1.14 deg    243 Ida
  253 Mathilde     66 x 48 x 46    103.3  417.7   hrs   4.31 yrs      C       2.646 AU       0.2660        6.71 deg    253 Mathilde                                  
  433 Eros         33 x 13 x 13      6.69   5.270 hrs   1.76 yrs      S       1.458 AU       0.2229       10.83 deg    433 Eros
  951 Gaspra       19 x 12 x 11     10      7.042 hrs   3.29 yrs      S       2.209 AU       0.1738        4.10 deg    951 Gaspra
 1566 Icarus           1.4         0.001    2.273 hrs   1.12 yrs      U       1.078 AU       0.8269       22.86 deg   1566 Icarus            
 1620 Geographos       2.0         0.004    5.222 hrs   1.39 yrs      S       1.245 AU       0.3356       13.34 deg   1620 Geographos 
 1862 Apollo           1.6         0.002    3.063 hrs   1.81 yrs      S       1.471 AU       0.5600        6.36 deg   1862 Apollo
 2060 Chiron           180          4,000   5.9   hrs   50.7 yrs      B      13.633 AU       0.3801        6.94 deg   2060 Chiron
 2530 Shipka                                            5.25 yrs              3.019 AU       0.1237       10.10 deg   2530 Shipka
 2703 Rodari                                            3.25 yrs              2.194 AU       0.0572        6.04 deg   2703 Rodari
 3352 McAuliffe       2 - 5                             2.57 yrs              1.879 AU       0.3686        4.77 deg   3352 McAuliffe
 3840 Mimistrobell                                      3.38 yrs              2.249 AU       0.0831        3.92 deg   3840 Mimistrobell
 4179 Toutatis   4.6 x 2.4 x 1.9   0.05     130.  hrs   3.98 yrs      S       2.512 AU       0.6339        0.47 deg   4179 Toutatis
 4769 Castalia      1.8 x 0.8      0.0005               1.10 yrs              1.063 AU       0.4831        8.89 deg   4769 Castalia  
 4979 Otawara          5.5         0.2                  3.19 yrs              2.168 AU       0.1449        0.91 deg   4979 Otawara
 5535 AnneFrank        4.0                              3.29 yrs              2.212 AU       0.0643        4.25 deg   5535 AnneFrank                        
 9969 Braille       2.2 x 1.0                           3.58 yrs              2.341 AU       0.4336       29.0  deg   9969 Braille
25143 Itokawa          ~1                               1.52 yrs              1.324 AU       0.2789        1.71 deg        1998 SF36
1 Ceres - The largest and first discovered asteroid, by G. Piazzi on January 1, 1801. Ceres comprises over one-third the 2.3 x 1021 kg estimated total mass of all the asteroids.
2 Pallas - The 2nd largest asteroid and second asteroid discovered, by H. Olbers in 1802.
3 Juno - The 3rd asteroid discovered, by K. Harding in 1804.
4 Vesta - The 3rd largest asteroid, Vesta appears to have a basaltic crust overlying an olivine mantle, indicating differentiation has occurred. Imaged by the Hubble Space Telescope in 1995.
45 Eugenia - Believed to have a small satellite S/1998 (45) 1 in near circular 4.7 day orbit as reported in IAU Circular #7129
140 Siwa - Originally scheduled for July 2008 flyby by the Rosetta spacecraft on its way to Comet P/Wirtanen. The mission has been rerouted.
216 Kleopatra - Imaged by Arecibo radar, shown to have unusual "dog-bone" shape.
243 Ida - Imaged by Galileo on 28 August 1993. These images showed a small satellite, subsequently named Dactyl, in orbit about Ida.
253 Mathilde - Target of NEAR mission flyby on 27 June 1997 en route to 433 Eros.
433 Eros - Near-Earth asteroid being studied from orbit by the NEAR mission, which flew by Eros in February 1999 and went into orbit in February 2000.
951 Gaspra - Imaged by Galileo on 29 Oct 1991.
1566 Icarus - Highly eccentric Earth-crossing orbit.
1620 Geographos - Scheduled to be visited by Clementine before a computer malfunction cut the mission short.
1862 Apollo - Earth-crossing asteroid.
2060 Chiron - Asteroid/Comet (95P/Chiron) in chaotic eccentric orbit near Saturn and Uranus. 14 February 1996 perihelion was the subject of the Chiron Perihelion Campaign.
2530 Shipka - Originally scheduled for October, 2008 flyby by the Rosetta spacecraft on its way to Comet P/Wirtanen. The mission has been rerouted.
2703 Rodari - Originally scheduled for May, 2008 flyby by the Rosetta spacecraft on its way to Comet P/Wirtanen. The mission has been rerouted.
3352 McAuliffe - Amor (Mars-crossing) asteroid originally scheduled for 1999 flyby by the New Millenium Deep Space 1 spacecraft.
3840 Mimistrobell - Originally scheduled for September, 2006 flyby by the Rosetta spacecraft on its way to Comet P/Wirtanen.
4179 Toutatis - Double object, probably in contact, one 2.5 km and one 1.5 km diameter (estimated), imaged by Arecibo and Goldstone radar. Close approach to Earth of this object (about 1.5 million km) will occur on 29 September 2004.
4660 Nereus - Near-Earth asteroid, target of NEAP (Near Earth Asteroid Prospector) rendezvous.
4769 Castalia - Double-lobed near-Earth asteroid, each lobe about .75 km diameter. Imaged by Arecibo radar.
4979 Otawara - Originally scheduled for July 2006 flyby by the Rosetta spacecraft on its way to Comet P/Wirtanen. The mission has been rerouted.
5535 AnneFrank - Target of November 2002 flyby by the Stardust spacecraft on its way to Comet P/Wild 2.
9969 Braille - Near-Earth asteroid target of 28 July 1999 flyby by the Deep Space 1 spacecraft.
25143 Itokawa - (1998 SF36) Near-Earth asteroid target of 2005 orbit and 2007 sample return by the Muses-C spacecraft.

New masses calculated for 3 largest asteroids - U.S. Naval Observatory press release, 7 January 1998

Notes on the Fact Sheets
Asteroid Home Page
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Author/Curator:
Dr. David R. Williams, dwilliam@nssdc.gsfc.nasa.gov
NSSDC, Mail Code 633
NASA Goddard Space Flight Center
Greenbelt, MD 20771
+1-301-286-1258

NASA Official: Ed Grayzeck, edwin.j.grayzeck@nasa.gov
Last Updated: 01 September 2004, DRW