Tag Archives: Astronomy

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.

Vulcan? But that’s not logical…

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The news that “Vulcan” topped the poll results taken by the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View, California as a possible name for one of the two tiny moons newly discovered to be orbiting Pluto has gotten quite a bit of press this week. In 2012, Mark Showalter of SETI, working with scientists on the New Horizons mission sending a probe to Pluto, found a tiny fifth moon orbiting the icy world. Showalter was also the lead author of the discovery of a fourth moon in 2011 using observations from the Hubble Space Telescope.

Pluto

This image, taken by NASA’s Hubble Space Telescope, shows five moons orbiting the distant, icy dwarf planet Pluto.

As SETI contemplated what names to propose for these two newly-discovered moons, they opened the question to the public in an on-line poll.  Inspired by a tweet from William Shatner, the actor who became famous playing Capt. James T. Kirk in the original Star Trek television program (1966-69), Vulcan, Pluto’s mythological nephew and the name of a fictional world in Star Trek’s imagined universe, became the top vote getter.  Leonard Nimoy, who played Spock, the most famous Star Trek Vulcan, reportedly tweeted that naming one of the two moons “Vulcan” would be the “logical choice.”

shatner

nimoy

But did you know that there already was a Vulcan?  Or, actually, there wasn’t.  But astronomers thought that there was.

Since the 18th century, astronomers worried that the orbit of the innermost planet in the solar system, Mercury, did not behave the way that they expected.  By the mid-nineteenth century they knew that perturbations in the orbit of Uranus had just (in 1846) resulted in the discovery of Neptune, the first planet to be predicted mathematically before it was confirmed through observation.  Could that also apply to Mercury? Was there another planet orbiting between Mercury and the Sun that could explain Mercury’s orbit?  Urbain Jean Joseph Leverrier, whose calculations had been used to discover Neptune, thought so.  By 1859, amateur and professional astronomers started searching.

And they found some things.  Some scientists reported seeing a bright, star-like object orbiting near the Sun.  And others saw circular shapes transiting (or crossing) the face of the Sun. It must be Vulcan, they thought!  Some textbooks printed in the 1860s and 1870s even listed Vulcan as a planet. (For, indeed, Pluto is not the first body to have been considered a planet and then reclassified. Ceres, the spherical body in the asteroid belt, was also called a planet when it was discovered in 1801 but then reconsidered when the many other bodies discovered in that same region of space became known as the asteroid belt.)  But the observations of Vulcan did not compute.  They were not consistent.  According to Newton, and to vast experience, planets, above all, were predictable in their orbits. Any deviation was not acceptable.  That’s how Kepler decided that planets did not travel in circular orbits. So when scientists looked for Vulcan where it was predicted to be visible and they could not find it, they started to doubt that Vulcan existed.

When something does not move as predicted, astronomers start looking for a perturbing mass.  That is in fact how dark matter was detected, and after almost 50 years, finally accepted as a major factor in controlling the motions of things like stars and galaxies in the universe.  In the early 20th century, astronomers thought that the existence of a faint disk of material around the sun, called the Zodiacal Light, might be massive enough to make Mercury’s orbit shift in the way it appeared to do.  But in the end, Einstein solved the problem (literally) and Vulcan was no more.  In 1915, Einstein’s General Theory of Relativity explained the shifts in Mercury’s orbit without the presence of another world orbiting nearer to the Sun.  Vulcan, which had never existed, entered the history books.  But astronomers still use the name: NASA’s project to detect new planets has been called “Project Vulcan.”

The names of Pluto’s moons have still not been decided.  The International Astronomical Union, the worldwide professional organization of astronomers, will make the final choice.  They may choose “Vulcan.” Or they may decide that there was already a Vulcan. Except that there wasn’t.

Margaret Weitekamp and David DeVorkin are curators in the Space History Department of 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.

Dome In A Day: Progress on the Public Observatory Project

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[youtube=http://www.youtube.com/watch?v=t24CFnyvcOE&hl=en&fs=1&]

The Public Observatory Project (POP) is nearer to completion.  We are in the process of installing a large professional Boller & Chivens telescope in a 22-foot dome that will be available for four hours each day (weather permitting) to view the Sun, Moon and planets from the east terrace of the Museum. POP will be available for casual observing and for school and special interest groups. It will also be the Museum’s nerve center for the International Year of Astronomy throughout the rest of 2009 and well into 2010.

Over the past two weeks many people have devoted many many hours to making the Public Observatory Project (POP) closer to being ready for the public.  Once the rim of the foundation had been cast, Andy, Katie and John used both GPS and a simple shadow gnomon to determine the north-south alignment, marking the line on the rim of the foundation.  Then, a concrete pad was poured and leveled, followed by thick pads of Sorbothane, then a 6 x 6 foot iron plate, and finally the sole plate, tilted 3.6 degrees to the north to accommodate the latitude difference between Harvard, Massachusetts, the original home of the Boller & Chivens telescope, and Washington, D.C.  Larry and Ted continued to work on modernizing and ruggedizing the electronic relay system for the telescope, the pier was poured and trimmed, and finally, this week, assembly started.

The dome gore sections were brought to the terrace, as well as the walls, with the help of Joe Deregt, who came all the way from Australia to lead the charge.  The dome was assembled, then the walls went up.  Finally, yesterday, the 60-ton crane arrived, the pedestal was fitted to the pier base, and, by noon, the dome was lifted into place, carefully fitted by adjusting the base, and finally, after testing dome rotation (smooth!) the walls were secured to the foundation rim. At the end of the day, Frank, Stephanie, Joe and David were treated to dinner by curators from the Division of Space History!

More background on this project is provided in a previous blog post.

Dr. David DeVorkin is curator of the History of Astronomy in the Space History Division of the National Air and Space Museum.