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Mercury magazine

Spring 2007 - Volume 36, Number 2

Spring 2007 - Volume 36, Number 2

Table of Contents



[12] The Cosmos in the Classroom Conferences, Andrew Fraknoi
A popular series of meetings is drawing praise for nurturing the growth of astronomy and space science education in the United States.

[18] The Power of Zeus, James C. White II
A clap of thunder tells us lightning is nearby, but these atmospheric sparks have been observed in other planets' atmospheres, too.

[26] Planet-Hunting, "Transit-Style", Bandu Jayawardene, Graeme White, David Blank, Alex Hons, Arie Verveer, and James Biggs
Small variations in a star's brightness may suggest intrinsic variability, but they might also betray the presence of a planet orbiting the star.

[32] Learning and Communicating Across Disciplines, Anna H. Spitz
The University of Arizona's LAPLACE facilitates interactions between life and physical sciences through joint research in astrobiology.


[4] Editorial, James C. White II
Smacked to the Stars

[5] Armchair Astrophysics, Christopher Wanjek
Insights Bring More Confusion

[6] Planetary Perspectives, Daniel D. Durda
A New Spin on Small Asteroids

[7] Echoes of the Past, Katherine Bracher
The Rings of Uranus

[8] Astronomer's Notebook, Jennifer Birriel
Sources of Cosmic Infrared Background

[9] Annals of Astronomy, Clifford J. Cunningham
Who Discovered Jupiter’s Satellites

[10] Societal Impact , Michael G. Gibbs
In the National Interest

[11] Education Matters, David Bruning

[38] Works of Note

[40] Sky Events, Richard Talcott

[44] Society Scope

[46] Last Word, Michael Bennett

The Cosmos in the Classroom Conferences

by Andrew Fraknoi

Our best estimates are that roughly 250,000 college students take an introductory astronomy course in the United States each year. While this is only a fraction of those who watch television shows about UFOs or movies like Spiderman 2 (with its ridiculous home-made fusion machine cobbled together on an abandoned dock), those courses are nevertheless a very significant interface between the astronomical community and the educated voting public. After all, this means that every four years we expose a million college students to the story of the planets, stars, and galaxies with which they share the Universe.

For many non-science students, an astronomy course may be their one contact with the physical sciences during their entire college careers. We owe them an experience that they will remember with pleasure -- not necessarily because it was easy, but because it gave them a real sense of our understanding of the Universe and our connections with it, as well insights into the nature and process of science.

The Power of Zeus

by James C. White II

I was six years old when I discovered I had the power of Zeus. By merely dragging my feet across a wool rug in my house, I could unleash lightning bolts -- well, some tiny sparks, at least -- on my mortal parents.

It did not take me long to find out that lightning, those real Zeusian bolts of electricity from the sky, came about in essentially the same way.

As you walk across a rug, you strip electrons -- tiny, discrete units of negative electrical charge -- from it, and that extra charge on you makes you slightly negatively charged. When your hand nears a doorknob (or someone’s earlobe), Nature says, "Away extra charge!" and a spark jumps between finger and knob. Do you not believe that you, too, can make mini-lightning? Drag your

When Nature works on larger scales like those of big, fluffy clouds in the atmospheres of Earth or mighty Jupiter, the sparks are even bigger, and the energy is enormous. In a typical terrestrial lightning bolt, striking down from a cloud or springing up from the ground to a cloud, the energy is greater for a fraction of a second than that produced by all the electrical power generating plants in the United States. That more than one hundred bolts every second are striking Earth somewhere makes one realize (again) how powerful Nature can be.

Planet-Hunting, "Transit-Style"

by Bandu Jayawardene, Graeme White, David Blank, Alex Hons, Arie Verveer, and James Biggs

One of the most exciting astronomical activities of the last several years has been the search for transiting extrasolar planets—those orbiting stars other than our Sun. And of particular interest are "transiting."

When a transiting ESP's orbital motion carries it in front of its parent star, the planet blocks some of the star's light, and astronomers observe a diminution in the star’s brightness. How much the light decreases depends almost exactly on the ratio of the size of the planet to that of the star, and, as the spectral type of the star tells us its diameter, we can calculate the planet's diameter. In fact, this is the only way known at present for directly finding the diameters of ESPs and for indirectly inferring the ESPs' masses.

Learning and Communicating Across Disciplines

by Anna H. Spitz

Although researchers have been studying astronomy and biology for hundreds of years, astrobiology is relatively new to the list of "named" fields of scientific research. Astrobiology has been termed multi-, cross-, inter-, or transdisciplinary. Because academic research tended to more and more specialization during the 20th century, many scientists are at a loss about what it means to collaborate in multidisciplinary work. Astrobiology encourages the new 21st century paradigm under which researchers, educators, and students seek new multi- and interdisciplinary solutions to profound research

The trick is how to achieve close coordination of diverse scientific disciplines and programs. Too often researchers are focused on their very specific areas of research or at best on the general subject areas such as astronomy or biology. But in order for scientists working at the confluence of these two broad scientific disciplines to make significant and comprehensive discoveries in a specific area of expertise, they must have an appreciation and understanding of the techniques, limitations and power of disciplines other than their own. This multidisciplinary approach is critical for solving some of the most fundamental questions facing humankind -- from how did life begin to how will the changes in Earth's climate affect life's future on this planet.