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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