Tag Archives: planets

The Abbreviated History of a Scientist (Namely, Myself)

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My first word was JET, since we lived near an Air Force base and experienced sonic booms on a regular basis. My fascination with the heavens took off from there.

Growing up, my family went camping and backpacking a lot, and one of my clearest memories of that time is looking up at a dark, dark sky and pointing out satellites to each other, those little moving points of light that are sometimes so faint I could only see them in my peripheral vision. Far above airplanes, they fly through our sky.

For a ‘day on the job’ in high school, I tagged along with a local pilot, as he taught ground classes that were only slightly beyond my math level at the time, and then taught flight lessons in a small four-seater airplane. Talk about a great incentive for learning more math! Looking down on suburbs and ranches as we flew snug up against the front range of the Rocky Mountains, I fell in love with the idea of flying not as a passenger but as a pilot.

I went to countless planetarium shows growing up, and was encouraged in my interest of Hubble images, showing colorful and fantastically-shaped galaxies far away, and the polar caps of Mars up close. In high school, I went to occasional talks by astronomers, and by the time I got to college, I was ready to hear a lot more! And the pilots of the telescopes and spacecraft we use to study the heavens are engineers…so, I began college as an aerospace engineer.

The class I remember best from my first year of college is Intro Astronomy, the first term of which dealt with our own Solar System…how did the massive greenhouse atmosphere of Venus get that way, if it started out similar to Earth (as we think it did)? Well, you can think about it like feedback on Jimi Hendrix’s guitar during a performance: when he gets close to one of the speakers, the blasting music vibrates his guitar strings, which causes louder output from the speakers, which again increases the vibration of his guitar strings. This is the analogy that made positive feedback in a climate system (the runaway greenhouse effect) easy to understand for me.

So instead of being interested in airplanes, I found myself interested in spacecraft. And instead wanting to fly them, I found myself wanting to see all the data they returned. My fascination with the heavens took off again. Instead of becoming an engineer, I became a physicist (and sociologist, but that’s another story!), one who studies planets.

I talked about my interest with one of the new faculty in the Astrophysical and Planetary Sciences department, and was taken on as an undergraduate researcher. It’s wild to think back to that time, at how little of what I know now I knew then, of how new I was to the process of doing research. The first thing to really grab me, to pull me in hook, line, and sinker, was attending the 33rd Lunar and Planetary Science Conference. I was awed by the throng of people at the poster session, where I stood presenting my research, talking loudly over the din. I was impressed by the snappy talks where 50 – 100 people sat listening, taking notes, and whispering commentary to their neighbors. I wanted to be part of that world.

Michelle Selvans

Here I am circa 2002 with my poster, at the 33rd Lunar and Planetary Science Conference.

Now I think of it as ‘this’ world, the world I’m immersed in through my work life. I just returned, along with most of the Museum’s Center for Earth and Planetary Studies staff, from the 44th Lunar and Planetary Science Conference.

It was every bit as engaging as the first one I attended, but for different reasons. Instead of being in awe of the whole spectacle, I feel a sense of belonging. I am now a postdoctoral fellow with an undergraduate mentee who presented work he did with me last summer. I sat down for long talks with researchers I’ve admired for years, to brainstorm ideas for research projects we might work on together. I gave a talk on my research on the origins of tectonic features on Mercury, and a poster on some of the outreach I do in the Museum. I caught up with old friends I went to graduate school with, and new ones I’ve met recently at workshops. I have become a pilot in a sense, the one at the controls of my own work experience.

So here I find myself, a planetary scientist, working with amazing people on fascinating projects. I could have become a pilot or an engineer, but instead I’m a scientist working in a museum that honors all three professions. This is one of those times I count my blessings, and smile!

Michelle Selvans is a planetary scientist in the National Air and Space Museum’s Center for Earth and Planetary Studies.

Pluto’s Secret: Writing the Museum’s First Children’s Book

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How did three staff members at the National Air and Space Museum get to collaborate on the Museum’s first children’s book, Pluto’s Secret: An Icy World’s Tale of Discovery?  The short answer is that this is an extraordinary place to work.  And when people are as generous with their time and talents as my collaborators have been, neat stuff happens.

Pluto’s Secret: An Icy World’s Tale of Discovery

The idea that became Pluto’s Secret began in the Writers’ Group that I hold for Museum curators and fellows.  We meet twice a month to share mutual problems we encounter in our research and writing of aviation and space history.  David DeVorkin, the Museum’s senior curator of space astronomy (who was present at the 2006 International Astronomical Union meeting in Prague during which astronomers voted on Pluto’s new designation), told the group about an article that he was writing about Pluto’s discovery and reclassification. David’s article examined how disagreements among astronomers over how Pluto should be categorized reflected pre-existing divisions in the field of astronomy. (You can find David’s final essay in Exploring the Planets (Palgrave, 2013)). David’s draft was called, “Pluto: The Problem Planet.” As a mother who spent many hours reading to my then-preschool son, our oldest, I thought, “That would be a great title for a children’s book!”

So, during my commutes in and out of Washington, DC, I added the story of Pluto’s discovery to the repertoire of tales that I would tell my son in the car to pass the time. Standard fairy tales had gotten repetitive and boring—I had even started retelling the same stories from different points of view to vary them, a skill that became useful for Pluto’s Secret —so I wanted something new.

When I eventually suggested Pluto’s tale to Trish Graboske, the Museum’s publications officer, she suggested the addition that made the Museum’s first children’s book a reality: Diane Kidd, the Museum’s early childhood manager, is also a professional children’s books illustrator! If she would illuminate our book, we might really have something. David and Diane agreed to take on the project with me and the rest is history (of science).

Margaret, David, and Diane

Margaret Weitekamp, David DeVorkin, and Diane Kidd

The collaboration between the three of us became my favorite part of this project. Usually, we learned, a children’s book illustrator might never meet the author at all. (Diane is working on a blog entry about her process to appear soon.)  This time, we met as a group to discuss the concept and we worked together, in person, throughout the whole process. I wrote and rewrote the text. Diane patiently subjected her beautiful artistic illustrations to David’s exacting reviews to check all of the details: the right telescopes, the correct astronomical domes, and even appropriate equations floating above Percival Lowell’s head. And David helped to refine the story with me. My son enjoyed (endured?) MANY bedtime readings (“When is it going to be real book?”), which were often interrupted as I scribbled on the pages to edit an awkward phrase or clarify a point.

At one point, David suggested a perspective that put everything in focus: Pluto does not change! Scientists’ ideas about Pluto changed as they learned more, but the icy world Pluto is just Pluto—out there on the edge of the solar system, being itself. The story needed a different point of view. It wasn’t the story of the scientists, interesting as they were. “Pluto, the Problem Planet” became Pluto’s Secret, the story of an icy world on the edge of the solar system that did not fit the label that scientists wanted to give it. (In fact, in 2006, because of Pluto, astronomers defined “planet” for the very first time.) Diane thought that kids would connect with the character of the icy world who was not bad, just different, and did not always follow the grown-ups’ arbitrary rules.

It’s so exciting to see Pluto’s Secret out in print. I’ve finally gotten to read a real, bound version to my three children at bedtime. And we look forward to telling this tale of discovery to audiences at the Museum and around the D.C. area. Come out and see us!

Margaret A. Weitekamp is a curator in the Space History Department of the National Air and Space Museum.

Scratching Beneath the Surface

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What’s inside a planet? What instruments do scientists use to figure it out? And what clues does a planet’s surface give us?

On Saturday, April 21, Lisa Walsh and I, scientists from the Museum’s Center for Earth and Planetary Studies, invited visitors to the National Air and Space Museum’s Explore the Universe Family Day to think about these questions, through two hands-on activities relating to our research into tectonics on Mercury. As the MESSENGER (Mercury Surface, Space ENvironment, Geochemistry, and Ranging) spacecraft starts its second Earth year in orbit around Mercury, we interacted with approximately 900 kids and kids-at-heart, asking them to figure out what was inside balloons by using tools analogous to those used in planetary science (scales, magnets, and, slightly less analogously, a good hard shake), and to piece together a puzzle made from images of Mercury’s surface.

Evidently you can’t just do one piece of the puzzle, because often people stuck around until the whole thing was put together, talking with Lisa about MESSENGER results and her own research.

 

explore the universe

Lisa Walsh talks with young visitors about her research during the Explore the Universe Family Day at the National Air and Space Museum in Washington, DC on April 21, 2012.

Lisa studies wrinkle ridges, which form on the surface of a planet when rock layers are crunched in from the sides, like scuffing in the edge of a rug with your shoe. This causes the layers to fault and fold, leaving ‘wrinkles’ in the surface. Wrinkle ridges are found throughout the inner Solar System, and have been mapped in greater detail on Mercury during the last year than was possible before the arrival of MESSENGER. Lisa wants to understand why wrinkle ridges on Mercury are so much larger than those on the Earth’s Moon, and what they look like beneath the surface on both planetary bodies.

The balloons were seemingly irresistible, since holding one out to any passing kid and asking them if they wanted to figure out “What’s Inside?” usually resulted in them spending the time to figure out all six, whether with a cohort of siblings or fellow boy scouts, or with a parent as engaged as they were. The balloons separately contained sand, iron filings, yarn, a magnet, a marble, and beads, with the iron filings being the most popular for further investigation. As the afternoon progressed, I frequently interacted again with previous visitors to the table, when they brought back friends or family to check it out.

 

michelle selvans

Dr. Michelle Selvans helps young investigators as they determine the interior materials of balloons, using scales, magnets, and a good shake.

Every participant left the table with something in hand (sticker, button, poster, or a model of MESSENGER to put together at home). But even more gratifying was seeing everyone leave with an appreciation for who studies the planets in our Solar System (we do!), how they’re studied (for example, through missions like MESSENGER, using instruments like the multi-spectral and multi-resolution camera we depend on for our research), and why they’re studied.

Why do we as a species study our neighbors in space? Why do we look for Earth-like planets around neighboring stars (the ongoing Kepler mission)? Why even study our own planet, its life and climate and geology?

If you ask ten people these same questions, you could very well get ten different answers. We all have our own reasons for being interested in the world around us. Maybe we’re concerned about how to protect people from natural hazards like hurricanes or earthquakes. Maybe we want to know if we are ‘alone’ in the universe, or whether life in any form exists elsewhere. Maybe we are awed by the beauty, intricacy, and divinity of the physical universe and just want to commune with it more intimately. Maybe, like for myself, practical, personal, and spiritual reasons all factor in.

 

Mercury

Mosaic of high-resolution MESSENGER images taken at dawn, showing several newly-identified tectonic features (arrows). Made by Dr. Michelle Selvans.

 

I study large faults on Mercury, which cast long shadows at dawn and dusk, so they’re easy to see when we take pictures at those times of (Mercury) day. They’ve been mapped previously all across the surface (using images from before MESSENGER went into orbit), and appear to be placed in a pattern that suggests global-scale stresses. As we collect pictures at dawn and dusk, I am mapping the greater number of scarps that are being revealed, to see if the pattern holds. I also use the elevation maps that other MESSENGER Science Team members are producing, in order to understand the shapes of the most intriguing faults (measured across the scarp). Those shapes will help me model the fault structure below the surface, in order to understand the shallow structure of Mercury’s crust.

That’s a little bit of what I do here in the Center for Earth and Planetary Studies. What would you want to know about Mercury if you were in my place? Or about any other planet in our Solar System, or beyond? Why are you interested in those questions? And how could we go about figuring out the answers?

We would like to thank everyone who participated in the April 21 Family Day fun, as well as the MESSENGER spacecraft Education Team for developing the puzzle, and the Lunar and Planetary Institute Education Team for the inspiration behind the balloon activity (the Investigating the Insides module, on their Explore! website).

Dr. Michelle Selvans is a planetary geophysicist in the Center for Earth and Planetary Studies at the National Air and Space Museum.

Shedding Light on a Common Problem

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If you’ve been to any of the nighttime observing sessions at our Public Observatory, you might have wondered why we mostly view the planets and the Moon. After all, the Observatory houses a professional 16-inch telescope, and several other high-quality portable telescopes; shouldn’t they be able to show us great views of galaxies or nebulas?   They should, and they could, if they were located at what astronomers call a “dark site” — away from the city lights that often outshine the lovely stars of nighttime.

 

Public Observatory

The Observatory at night. Photo credit: National Air and Space Museum, Eric Long

The problem is light pollution. The International Dark-Sky Association (IDA) defines light pollution as “any adverse effect of manmade light.” This includes but isn’t limited to our disappearing view of the Milky Way and the difficulties astronomers experience in making observations of celestial objects. Living things experience many effects as well: nocturnal animal populations are shrinking as they have difficulty finding food and hiding from predators, sea turtle hatchlings can have trouble finding their way to the ocean and die, and migrating birds can be disoriented by lights. Emerging research on the effects on humans indicates several problems associated with disruption of circadian rhythms and melatonin production, not to mention the safety-related dangers that come with poor visibility at night caused by glaring lights. But there are easy solutions: shielding lights to reduce glare, dimming lights to provide the right amount of light, and turning off lights when they’re not needed.

glare

Potential intruder hides in the glare from a “security light.” Photo credit: George Fleenor

When we decided to build the Observatory as a place for the public to gather and do astronomy together, we knew that light pollution would be an issue for us. But in order for it to be a convenient gathering place that people could get to easily, we knew we needed to build it in the city, where the people are. It was an easy decision when we considered what we were trying to do, and so far more than 2,000 visitors have enjoyed our nighttime observing sessions.

And yet we and our visitors long for darker skies and the ability to view fainter stars, galaxies, nebulas. Wouldn’t it be wonderful to be able to look at the majestic arms of the Milky Way from Washington, DC? It won’t happen for us until we have more intelligent and efficient street lighting here in our nation’s capitol and in the surrounding area. One way to work toward this is to collect scientific data that can be shared with decision makers to demonstrate what our current situation is regarding light pollution, how it’s been changing, and its effects.

Since 2006, citizen scientists from around the world have been participating in a program called GLOBE at Night. It’s a worldwide attempt to measure light pollution and see how it varies from place to place and year to year. This year, there are four opportunities to participate: January 14-23 (right now!), February 12-21, March 13-22, and April 11-20. The dates are selected so that the Moon won’t be up in the sky when participants are making observations, because the Moon also brightens the sky and can outshine the stars, especially when it’s near a full moon.

Magnitude

The constellation Orion, as it appears under magnitude 2 (left) and magnitude 4 (right) skies. Photo credit: GLOBE at Night/NOAO

Want to join in? Here’s how it works: Go outside an hour or more after sunset and give your eyes a chance to adjust to the darkness. Find the constellation Orion by looking in the southern sky. GLOBE at Night provides magnitude charts that show what Orion looks like with different amounts of light pollution. Magnitude refers to how bright the stars are, and when you’re talking about light pollution, it describes the faintest stars that can be seen. Determine which magnitude chart looks most like what you see that night and report it online. The reports show up instantly on GLOBE at Night’s interactive map viewer, so you can compare what you see to what people in different places around the world see. On Saturday night, January 14, I reported magnitude 3 skies from the Public Observatory in Washington, DC, and I’d love to know what your skies are like!

 

Moon

The waxing gibbous Moon as we viewed it on December 3, 2011. Photo credit: National Air and Space Museum, Genevieve de Messieres

For now, we mostly stick to visually observing the planets from the Observatory’s perch at the National Air and Space Museum. These objects are bright enough and big enough to observe easily even under light polluted skies, and they aren’t especially sensitive to the unstable air in our area which blurs high-powered views. The Moon fascinates me every time I see it, even when I see it every day. I enjoy observing the planets and looking for subtle changes and details I never noticed before, and I think that many of our visitors wouldn’t disagree. And this past Saturday night, I delighted in a great view of the Orion Nebula, a star-forming region, through our telescopes. But I am hopeful for a future in which we can use our fantastic telescopes to see more of the farther, fainter wonders of our universe from the National Mall in Washington, DC.

Katie Nagy is an astronomy educator at the National Air and Space Museum in Washington, DC.