Natural History Magazine
Author of the column titled Universe
for Natural History magazine (circulation approximately 250,000)
| Spacecraft Behaving Badly | April 2008 |
| Fellow Traveler: Recalling Sputnik after Fifty Years | October 2007 |
| The Cosmic Perspective 100th Essay |
April 2007 |
| Little Neutral Ones | February 2007 |
| Delusions of Space Enthusiasts | November 2006 |
| Shocking Truths | September 2006 |
| When the Moon Hits Your Eye | June 2006 |
| Unfit for Vision | April 2006 |
| The Light Brigade | March 2006 |
| Exoplanet Earth | February 2006 |
| Fire and Ice | December 2005/January 2006 |
| The Perimeter of Ignorance | November 2005 |
| Energy to Burn | October 2005 |
| Heading Out | July/August 2005 |
| Fueling Up | June 2005 |
| Knock 'Em Dead | May 2005 |
| The Long and the Short of It | April 2005 |
| Living Space | March 2005 |
| Speed Limit | February 2005 |
| Send In The Clouds | December 2004/January 2005 |
| The Importance of Being Constant | November 2004 |
| Ringside Seat | October 2004 |
| The Information Trap | September 2004 |
| Vagabonds in Space | July/August 2004 |
| The Planet Parade | May 2004 |
| Launching the Right Stuff | April 2004 |
| Nebulous Categories | March 2004 |
| Great Masses From Little Ripples Grew | February 2004 |
Gravity in Reverse Selected for Best American Science Writing, 2004 Edited by Dava Sobel |
December 2003/January 2004 |
| Dark and Darker | November 2003 |
| Let There Be Light | October 2003 |
Winner, American Institute of Physics, 2005 Science Writing Prize |
September 2003 |
| The Rise and Fall of Planet X | June 2003 |
| Dust to Dust | May 2003 |
| Reaching for the Stars: America's Choice | April 2003 |
| Stick-in-the-Mud Science | March 2003 |
| Footprints in the Sands of Science | February 2003 |
| Delusions of Centrality | December 2002/Janaury 2003 |
| Going Ballistic | November 2002 |
| Let There Be Dark | October 2002 |
| The Periodic Table of the Cosmos | July/August 2002 |
| Hollywood Nights | June 2002 |
| On Being Baffled | May 2002 |
| The Five Points of Lagrange | April 2002 |
| The Colors of the Cosmos | March 2002 |
| Fear of Numbers | December 2001/January 2002 |
| Radio Bubble | November 2001 |
| Between the Planets | October 2001 |
| Over the Rainbow | September 2001 |
| By Any Other Name | July/August 2001 |
| Cosmic Plasma | May 2001 |
| Coming to our Senses | March 2001 |
| The Beginning of Science | February 2001 |
| The Universe as a Muse | December 2000/January 2001 |
| On Earth as in the Heavens | November 2000 |
| Doubling Time | October 2000 |
| One Universe: Telling the Story | February 2000 |
| Night Vision | February 2000 |
| Holy Wars | October 1999 |
| Size Does Matter | September 1999 |
| Between the Galaxies | June 1999 |
| Goldilocks and the Three Planets | May 1999 |
| Cosmic Horizons | March 1999 |
| Pluto's Honor | February 1999 |
| Certain Uncertainties (Part II) | November 1998 |
| Certain Uncertainties (Part I) | October 1998 |
| Space Travel Troubles | September 1998 |
| Things People Say | July/August 1998 |
| Water, Water | May 1998 |
| To Fly | April 1998 |
| The Greatest Story Ever Told | March 1998 |
| On Being Rarefied | February 1998 |
| Romancing the Equations | November 1997 |
| The Search for Planets | October 1997 |
| Coming Attractions | September 1997 |
| Zero Tolerance: Universe in a Raindrop | July/August 1997 |
| Gamma Ray Bursts | June 1997 |
| Galactic Engines | May 1997 |
| An Astrophysicist's Manhattan [Stan Mack Cartoon] | April 1997 |
| On Being Round | March 1997 |
| Gravitational Lenses | February 1997 |
| In Defense of the Big Bang | December 1996/January 1997 |
| Outward Bound | November 1996 |
| The Art of Detection | October 1996 |
| The Search for Life in the Universe | September 1996 |
| Forged in the Stars | August 1996 |
| Onward to the Edge | July 1996 |
| Ends of the World | June 1996 |
| Antimatter Matters | May 1996 |
| Journey From the Center of the Sun | April 1996 |
| When A Star is Not Born | March 1996 |
| Interpretations of the Cosmos | February 1996 |
| On Being Dense | January 1996 |
| When Galaxies Collide | December 1995 |
| The Tidal Force | November 1995 |
| Death by Black Hole | October 1995 |
| Adaptive Optics | September 1995 |
| The Milky Way Bar | August 1995 |
| Chaos in the Solar System | July 1995 |
| Cosmic Windows | June 1995 |
| The Shapley-Curtis Debate | May 1995 |
| The Coriolis Force | March 1995 |
| The Size & Age of the Universe | February 1995 |
| Romancing the Mountain Top | January 1995 |
