Daily Almanac for

Feb 15, 2012

• Skip Navigation
• Home
• Black History Month
• Atlas
• Encyclopedia
• Dictionary
• Thesaurus
• Features
• Quizzes
• Timelines
• Countries

• World & News
• United States
• History & Gov't
• Biography
• Sports
• Arts & Ent.
• Business
• Calendar & Holidays
• Health & Science
• Homework Center

• Fact Monster Kid's reference,
  games, quizzes

Fred Whipple

rocket scientist whose “dirty snowball theory” suggested that comets are made of ice and rock. He invented a thin shield of metal, called the Whipple shield, to protect spacecraft from high-speed particles.

Information Please® Database, © 2007 Pearson Education, Inc. All rights reserved.

• • Cite
  • Print
  • Email
  • Bookmark
    • Add bookmark
    • Add to del.icio.us
    • Digg It!
    • Add to Reddit

• 
  • Calculator
  • Spelling Checker
  • Place Finder
  • Distance Calculator
  • Periodic Table
  • Conversion Tool
  • Perpetual Calendar
  • Year by Year

24 X 7

Private Tutor

	24 x 7 Tutor Availability
	Unlimited Online Tutoring
	1-on-1 Tutoring

Explore Grade 4 Math , Math Answers