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Mercury magazine

Autumn 2015 - Volume 44, Number 4

Autumn 2015 - Volume 44, Number 4

Table of Contents



[19] Centerline or Edge: Where to View a Total Solar Eclipse, Tom Van Flandern and Fred Espenak
The centerline or the edge of the path of totality? Both offer the same sights during an eclipse but for different durations.

[25] Aiming High: Astronomy Undergrad Education at 6,800 Feet, Andreia Carrillo
An immersion course on Kitt Peak for astronomy majors teaches more than just astronomy.

[32] Martian Dust Storms: Fact and Fiction, Kathryn Mersmann
Mars is infamous for its dust storms, though it’s unlikely one could have stranded Mark Watney, The Martian’s fictional astronaut.

[36] Astronomy in the News
How Rosetta’s comet got its shape, a global ocean enveloping Saturn’s moon Enceladus, and charting the slow death of the universe. These are some of the discoveries that recently made news in the astronomical community.


[4] Perspectives, Paul Deans
Wait. Wait. Wait. Wow!

[5] First Word, Linda Shore
The Total Skywatcher’s Manual

[6] Annals of Astronomy, Clifford J. Cunningham
Biancani’s Book

[8] Astronomer’s Notebook, Jennifer Birriel
Life in the High-Redshift Universe

[9] Planetary Perspectives, Emily Joseph
Crossing the Horizon

[11] Strange New Worlds, ANU & Niels Bohr Institute
Looking for Planets Using an Old Solar System “Law"

[12] Armchair Astrophysics, Christopher Wanjek
Closest Quasar Powered By Two Black Holes, Not One

[14] Education Matters, Brian Kruse
Advancing Science Literacy at the Eyepiece

[15] Reaching Out, Bethany Cobb
Making the Universe More Relevant to a College Student

[17] Societal Impact, Richard Tresch Fienberg
Words Matter: Talking with the Public About the 2017 Eclipse

[46] ASP Tidings
IAU Meeting Newspapers Online

[48] Sky Sights, Paul Deans
It’s Geminid Time

[51] Reflections, NASA/ESA
Looking Back at Pluto

Centerline or Edge: Where to View a Total Solar Eclipse

by Tom Van Flandern and Fred Espenak

Editor’s Note: In the January/February 1997 issue of Mercury, a point/counterpoint pair of columns was published under the heading: “Where Is the Best Place to View a Solar Eclipse?” The points made by both authors — Fred Espenak and the late Tom Van Flandern — are as valid today as they were nearly 20 years ago. With the great American solar eclipse only two years away, and many people already planning their trip to totality, I thought readers might be interested in these opposing viewpoints.

Point: Going to the Edge

Tom Van Flandern

Traditionally, eclipse observers have flocked to the very center of the eclipse path, where the Moon obscures the Sun for the longest time. Yet eclipses are much more spectacular when viewed from near the edge of the path.

Counterpoint: Maxing Out the Experience

Fred Espenak

Most eclipse viewers crave every second of totality they can get. For them, there is only one place to view an eclipse: at the centerline.

Aiming High: Astronomy Undergraduate Education at 6,800 Feet

by Andreia Carrillo

How often can you attend a class at 6,800 feet, surrounded by 26 telescopes? When I heard that “Astronomy 461: Ground-Based Observatories” would be offered by the University of Michigan this year, I was so excited that I started recruiting some of my peers. Astro 461, taught by Professor Sally Oey, is a unique immersion class held at Kitt Peak National Observatory (KPNO) in Arizona. It is designed to educate students about the scientific, technical, and political aspects of doing research with ground-based observatories.

In this four-week class, students visit telescopes and regional observatories to learn about the instruments and their technical properties, supported by lectures from the professor, our Graduate Student Instructor Meghin Spencer, observatory staff, and guest speakers. Also studied is the sociopolitical significance of these scientific facilities, with field trips to other observatories, regional institutions, and museums to help us understand the local environment. Students also conduct research projects based on their own observations, data reduction, and interpretation.

I really wanted to experience these activities for myself. There were nine others, mostly majors in Astronomy and Astrophysics, accepted into the Spring 2015 program. After meeting everyone, I couldn’t wait to spend a month working alongside this group of amazing and driven minds!

Martian Dust Storms: Fact and Fiction

by Kathryn Mersmann

For years, science fiction writers from Edgar Rice Burroughs to C. S. Lewis have imagined what it would be like for humans to walk on Mars. As mankind comes closer to taking its first steps on the Red Planet, authors’ depictions of the experience have become more realistic.

Andy Weir’s The Martian begins with a massive dust storm that strands fictional astronaut Mark Watney on Mars. In the scene, powerful wind rips an antenna out of a piece of equipment and destroys parts of the astronauts’ camp.

Mars is infamous for intense dust storms, which sometimes kick up enough dust to be seen by telescopes on Earth. “Every year there are some moderately big dust storms that pop up on Mars and they cover continent-sized areas and last for weeks at a time,” said Michael Smith, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

However, It is unlikely that even these dust storms could strand an astronaut on Mars.

At Saturn, One of These Rings is Not Like the Others

NASA/Jet Propulsion Laboratory

When the Sun set on Saturn’s rings in August 2009, scientists on NASA’s Cassini mission were watching closely. It was the equinox — one of two times in the Saturnian year when the Sun illuminates the planet’s enormous ring system edge-on. The event provided an extraordinary opportunity for the orbiting Cassini spacecraft to observe short-lived changes in the rings that reveal details about their nature.

Like Earth, Saturn is tilted on its axis. During the course of its 29-year-long orbit, the Sun’s rays move from north to south over the planet and its rings, and back again. The changing sunlight causes the temperature of the rings — which are made of trillions of icy particles — to vary from season to season. During equinox, which lasted only a few days, unusual shadows and wavy structures appeared and, as they sat in twilight for this brief period, the rings began to cool.

In a recent study published in the journal Icarus, a team of Cassini scientists reported that one section of the rings appears to have been running a slight fever during equinox. The higher-than-expected temperature provided a unique window into the interior structure of ring particles not usually available to scientists.

“For the most part, we can’t learn much about what Saturn’s ring particles are like deeper than one millimeter below the surface. But the fact that one part of the rings didn’t cool as expected allowed us to model what they might be like on the inside,” said Ryuji Morishima of NASA’s Jet Propulsion Laboratory, Pasadena, California, who led the study.