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Table of Contents

Have You Ever Wondered…
by Geoffrey Giller

Section 1: Starstruck

1.1   How Is a Star Born?
        by Richard Brill and Margaret Hanson

1.2   How Long Do Stars Usually Live?
        by John Graham

1.3   How Do Scientists Determine the Life Cycles of Stars?
        by Terry D. Oswalt

1.4   How Do Scientists Determine the Ages of Stars?
        by Stephen A. Naftilan and Peter B. Stetson

1.5   Why Do Stars and Black Holes Spin?
        by Rhett Herman and Tsunefumi Tanaka

1.6   When a Star Spins, How Is its Gravitational Field Affected?
        by Peter Sutherland

1.7   How Can the Sun's Corona Be Hotter than Its Surface?
        by David Van Blerkom, Vic Pizzo, Leo Connolly and Jay M. Pasachoff

1.8   How Did Our Solar System Form?
        by Michael Jura

1.9   What Is the North Star?
        by Rich Schuler

1.10  Why Do Stars Twinkle?
         by John A. Graham

Section 2: Our Neighborhood: Earth and Moon

2.1   Does the Moon Also Have a Tidal Effect on Earth's Atmosphere?
        by Rashid Akmaev

2.2   What Would Happen to the Earth if the Moon Were Half as Massive?
        by Neil F. Comins

2.3   Why Do the Moon and the Sun Look so Much Larger near the Horizon?
        by Maurice Hershenson

2.4   What Is a Blue Moon?
        by George F. Spagna

2.5   Is It a Coincidence that the Moon's Period of Rotation and Revolution Are Identical?
        by Alan P. Boss

2.6   How Fast Is the Earth Moving?
        by Rhett Herman

Section 3: Planetary Puzzles

3.1   Why Are Planets Round?
        by Derek Sears

3.2   How Do Scientists Calculate the Mass of a Planet?
        by Barry Lienert and Gregory A. Lyzenga

3.3   How Do Planets Acquire Rings?
        by George F. Spagna

3.4   Is Jupiter a “Failed Star?”
        by Alan P. Boss and Alex Rudolph

3.5   Who Gets To Name New Planets?
        by Geoffrey Marcy

3.6   Is NASA Too Worried about Contaminating Mars?
        by Nathan Collins

Section 4: Flying Objects: Meteors, Asteroids and Comets

4.1   What Do We Know about the 2013 Russian Meteor?
        by John Matson and Margaret Campbell-Brown

4.2   How Can I Tell if a Strange Looking Rock Is a Meteorite?
        by William Sharp

4.3   Why Are Scientists Sure that a "Martian" Meteorite Really Came from Mars?
        by David W. Mittlefehldt, Richard N. Zare, Harry Y. McSween and Michael E. Lipschutz

4.4   What Causes a Meteor Shower?
        by Gregory Lyzenga

4.5   Will the Perseid Meteor Shower Ever Run Dry?
        by John Matson and Bill Cooke

4.6   Is "Asteroid Mining" Feasible?
        by David McKay and John S. Lewis

4.7   How Crowded Is the "Asteroid Belt"?
        by David Morrison, Michael Briley and Tom Gehrels

4.8   If Comets Melt, Why Do They Seem To Last for Long Periods of Time?
        by Greg Lyzenga

4.9   What Would Be the Environmental Effects if the Earth Collided with a Large Comet?
        by David Morrison and Gerrit L. Verschuur

Section 5: Galaxies and Nebulae

5.1   Why Do Images of Astronomical Nebulae Look Like Clouds on the Earth?
        by James R. Graham

5.2   How Do We Know our Location Within the Milky Way Galaxy?
        by Laurence A. Marschall

5.3   What Creates the Beautiful Spiral Arms around Galaxies?
        by Ray Carlberg, Debra M. Elmegreen, Bruce Elmegreen and Jerry Sellwood

5.4   How Do We Know that Distant Galaxies Are Composed of Matter Rather than Anti-Matter?
        by Stephen A. Naftilan and Scott Dodelson

Section 6: Black Holes and Gravitational Phenomena

6.1   If Light Cannot Escape Black Holes, Why Do We Detect Radiation from Them?
        by Stephen Reucroft, John D. Swain and John Gaustad

6.2   Is the Violent Behavior of Quasars Caused by Black Holes in Galaxies?
        by Roeland van der Marel

6.3   Why Didn't the Big Bang Immediately Collapse into a Black Hole?
        by George Musser, Robert J. Nemiroff, Christ Ftaclas and Edward L. Wright

6.4   What Exactly Is a 'Wormhole'?
        by Richard F. Holman, William A. Hiscock and Matt Visser

6.5   What Are Dark Matter and Dark Energy?
        by Robert Caldwell

6.6   Is Dark Matter Theory or Fact?
        by Rhett Herman and Shane L. Larson

6.7   When Will We Find Dark Matter?
        by Clara Moskowitz

Section 7: The Breadth of the Universe

7.1   Why Is the Night Sky Dark?
        by Karen B. Kwitter

7.2   Where Is the Universe Expanding To?
        by Alexander Kashlinsky

7.3   Does the Fact that the Universe Is Continually Expanding Mean that It Lacks a “Physical Edge?”
        by Stephen Reucroft, John Swain and Robert Nichol

7.4   How Do Astronomers Measure Distances to Galaxies at the Edge of the Universe?
        by Jay M. Pasachoff

7.5   If Galaxies Are Moving Apart at Increasing Speed, How Can They Collide?
        by Tamara Davis

Section 8: Space Exploration

8.1   How Do Space Probes Navigate Large Distances with such Accuracy?
        by Jeremy Jones

8.2   How Does the Gravitational "Slingshot" Effect Used with some Space Probes Work?
        by Jeremy Jones

8.3   Why Did NASA Decide To Launch Space Shuttles from Weatherbeaten Florida?
        by John Matson and Roger Launius

8.4   How Does Spending Prolonged Time in Microgravity Affect Astronauts?
        by Jeffrey Sutton

8.5   What Would Artificial Gravity Be Like for the Inhabitant of a Space Station?
        by Robert Ehrlich and John Taylor

8.6   Could the International Space Station Serve as a Repair Hanger for Satellites?
        by Jack Bacon

Section 9: Looking for Life

9.1   What Kind of Patterns Does the Search for Extraterrestrial Life Look For?
        by Peter R. Backus

9.2   Could Silicon Be the Basis for Alien Life Forms, Just as Carbon Is on Earth?
        by Raymond Dessy

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