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Letter From Fred Whipple




Letter From Fred Whipple

This letter to the STARDUST project was received from Fred Whipple. Dr.
Whipple is the originator of the "dirty snowball" theory for comets, and has
also discovered a few comets himself. The Whipple Shields that the STARDUST
spacecraft carries were named in his honor.  The Whipple Shields will protect
the spacecraft when it encounters Comet Wild-2 in 2004.  This letter will be 
placed on the microchip that will be carried on the STARDUST spacecraft to 
Comet Wild-2.  The letter has been scanned in and is available on the 
STARDUST home page:

http://stardust.jpl.nasa.gov/comets/whipple_letter.html

Ron Baalke
STARDUST Outreach
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   Center For Astrophysics
   Cambridge, Massachusetts, USA
   November 25, 1997

   To all Space Buffs:

   Comets have long been an unexplored wasteland.  Today we know
   that they are black and cold, consisting of ices and dust that coalesced
   from an interstellar cloud as it collapsed to form the solar system.

   Their physical structure is poorly known.  Some astronomers guess
   that comets have low densities, perhaps less than half that of water
   ice.  This material would be crushable in one's hands.  Even the
   ratio of ices to dust remains a subject of uncertainty.  Probably the
   physical structure varies over small distances such as a few meters.

   May Stardust tame comets to become terra cognita, of known
   structure and isotopic composition!!


                                    Fred L. Whipple