Fred Lawrence Whipple

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Whipple aged 95
Whipple aged 95
Asteroids discovered: 1
1252 Celestia February 19, 1933

Fred Lawrence Whipple (November 5, 1906–August 30, 2004) was an American astronomer.

He is best known for writing an influential paper (published in Astrophysical Journal from 1950 to 1955[1][2][3]) in which he proposed the "icy conglomerate" hypothesis of comet composition (later called the "dirty snowball" hypothesis). The basic features of this hypothesis were later confirmed, however the exact amount (and thus the importance) of ices in a comet is an active field of research, with most of the recently obtained data[4] pointing to a low contribution of ices to a comet's mass (dubbed the "icy dirtball" hypothesis).

Whipple, the son of a farmer, was born November 5, 1906, in Red Oak, Iowa. An early bout with polio ended his ambition of being a professional tennis player. Whipple studied at Occidental College in southern California, then majored in mathematics at the University of California at Los Angeles.

A class in astronomy turned him in that direction, and he received a doctorate in that subject in 1931 from the University of California, Berkeley. While in graduate school, he helped map the orbit of the newly discovered planet Pluto.

He joined Harvard College Observatory in 1931 and studied the trajectories of meteors, confirming that they originated within the solar system rather than from interstellar space.

In 1933, he discovered the periodic comet 36P/Whipple and the asteroid 1252 Celestia. He also discovered or co-discovered five other non-periodic comets, the first of which was C/1932 P1 Peltier-Whipple, independently discovered by the famed amateur astronomer Leslie Peltier.

During World War II, he invented a device for cutting tinfoil into chaff to confuse enemy radar tracking Allied aircraft. He was awarded a Certificate of Merit for this in 1948.

He also invented a "meteor bumper" or "Whipple shield", which protects spacecraft from impact by small particles by vaporizing them.

In 1955 he became director of the Smithsonian Astrophysical Observatory (SAO), remaining in this post until 1973.

He anticipated the era of artificial satellites and organized the members of Operation Moonwatch to track them. These groups were the only ones prepared and ready to make observations when the Soviet Union unexpectedly launched Sputnik I in 1957.

Whipple died in 2004, aged 97.

[edit] Honors

Awards

Named after him

[edit] Notes

  1. ^ Whipple, Fred L. (1950). "A Comet Model. I. The acceleration of Comet Encke". Astrophys. J. 111: 375–394. 
  2. ^ Whipple, Fred L. (1951). "A Comet Model. II. Physical Relations for Comets and Meteors". Astrophys. J. 113: 464. 
  3. ^ Whipple, Fred L. (1955). "A Comet Model. III. The Zodiacal Light". Astrophys. J. 121: 750. 
  4. ^ Horst Uwe Keller at al., "Deep Impact Observations by OSIRIS Onboard the Rosetta Spacecraft", Science 310(2005), p. 281; online abstract

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