Archive for the 'Astronomy' Category

Shedding Light on a Common Problem

Published by The National Air and Space Museum on January 18, 2012 in Astronomy.
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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.

Mapping Everything

Published by The National Air and Space Museum on September 30, 2011 in Astronomy and space.
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The universe is about 13.7 billion years old and has expanded since its beginning at the Big Bang. Because distant objects appear to be receding as the universe expands, the light from them is “stretched” out, altering its wavelength to the red part of the electromagnetic spectrum.

This “redshift” can be measured for every object in deep space. The more distant the object, the greater its redshift. The relationship between distance and redshift was first described by Edwin Hubble in 1929 and remains fundamental to our understanding of the expanding universe.

Light from distant objects has been traveling towards the Earth for billions of years. In other words, we see distant objects as they appeared when the light left them. It is therefore possible to use telescopes to peer into the past. As astronomers have observed to ever more distant objects, it became possible to see into the very early stages of the universe. At the very edge of the observable universe, it is possible to detect electromagnetic radiation in all direction.

This cosmic microwave background radiation is the leftover energy from the Big Bang and the origins of our universe. This background radiation is literally the “echo” of the Big Bang.

WMAP

Cosmic background radiation as measured by the Wilkinson Microwave Anisotropy Probe (WMAP).

This illustration shows the cosmic background radiation as measured by the Wilkinson Microwave Anisotropy Probe (WMAP). This spacecraft was launched in 2001 into a halo orbit around the L2 libration point beyond Earth’s orbit. The cosmic background radiation was emitted about 13.7 billion years ago in the aftermath of the Big Bang, and has been stretched to the microwave part of the electromagnetic spectrum by the expansion of the universe. The colors indicate the intensity of the background radiation, which can be measured as temperatures barely above absolute zero. Reds signify temperatures about 0.0002 degrees Kelvin higher than blue areas. These differences reflect the “clumping” of matter that would later occur in the early history of the universe. This 360-degree view of the night sky has been mapped to a flat surface in the same way a global map of Earth is projected to a sheet of paper.

local galaxies

Local Group of Galaxies

The chart above shows the Local Group of galaxies. This gathering of galaxies is bound together by their mutual gravitational attraction. The largest two galaxies in the Local Group are the Milky Way and Andromeda. These two galaxies are approaching each other. About three billion years in the future they may merge to form a new, larger galaxy. Each galaxy is shown here about three times its actual size.

Sloan Diagram

Sloan Digital Sky Survey at 2 Billion Years

 

This chart above shows data from the Sloan Digital Sky Survey indicating the distribution of galaxies in the universe. The Local Group is at the center of this diagram, but it is too small to be visible at this scale. Dots show the density of galaxies, each consisting of hundreds of billions of stars. The positions were determined by measuring the redshift of each galaxy and their angular position.

sloan diagram

Sloan Digital Sky Survey at 10 Billion Years

As we peer into greater distances, we are in effect seeing back in time. Telescopes do not show deep space objects as they are – they show objects as they were billions of years ago. Because of this, representations that attempt to show the entire universe need to incorporate time as well as space. As we look out in space, and back in time, vast distances can be referred to as a “lookback time.” This chart shows data from the Sloan Digital Sky Survey. Close to the center, small dots show the density of galaxies. Beyond a lookback time of about 5 billion years, most of the dots represent quasars instead of galaxies. Quasars, or “quasi-stellar” objects, are likely the cores of energetic galaxies. The objects were much more plentiful in the early universe and emitted enormous amounts of radiation. Due to their distance only their energetic emissions are visible. At the very edge of what is visible, we can detect the cosmic microwave background.

Roger Launius is a senior curator in the Space History Division of the National Air and Space Museum.

 

The Perseids Are Coming!

Published by The National Air and Space Museum on August 4, 2011 in Astronomy, Education and News & Events.
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The Perseids are coming!  The most consistently best meteor shower of the year, the “Perseids,” (PER-see-ids) will reach their peak next week.   The earliest arrivals start around August 7 and the final stragglers show up about two weeks later, but the shower peaks strongly in the August 11-13 timeframe.  At the peak, as many as 60 or more Perseids might be seen in an hour, under favorable observing conditions; in 2011 the observed peak rate should be about half that, due to moonlight.

Meteor showers occur when the Earth encounters a stream of debris shed by a passing comet or asteroid.  The high speed of the material results in a lot of friction, making the debris particles glow brightly, like the filament of an old-fashioned light bulb.   Periodic comet 109P Swift-Tuttle is the source of the material causing the Perseid meteor shower.

Route 66

Route 66. The parallel lines of the road appear to converge on a single vanishing point in the center of the photograph.

Material released along a comet’s orbit is moving in more-or-less parallel paths when the Earth’s atmosphere is encountered.   Artists and drafts-persons are quite familiar with the “vanishing point” perspective created by looking among and along parallel lines.  In the photo below, the road side lines appear to converge on the horizon due to this effect; any objects approaching the observer along those lines would appear to be moving on a radial path with respect to that vanishing point.

A similar case of apparent radial motion arises when the Earth encounters the Swift-Tuttle debris stream every year in mid-August.  The meteors produced appear to radiate from a point in the sky in the constellation Perseus (named for the mythological Greek hero who slew the Gorgon Medusa amongst other exploits).  Meteor showers are named for the constellations in which their radiants reside, hence the upcoming shower is known as the Perseids.

Here is a diagram showing this radial pattern for the Perseids. It can also be seen in the photograph of a Perseid shower below (somewhat distorted by the camera).

 

Perseids

This image shows two composite views taken on the night of Aug. 11, 2010. The image on the left shows a collection of observations taken from 42 single station events over Huntsville, Ala. The image on the right shows a composite view from 39 single station events over Chickamauga, Ga. Courtesy of NASA/MSFC/D. Moser, NASA's Meteoroid Environment Office

The best way to see Perseid meteors is to look at or near the constellation Perseus in the sky, on or near the date Earth encounters the debris stream.  In general, meteor viewing is best in the wee hours of the morning.  Just as your front windshield collects more bugs than the back window, the leading side of the Earth collects more meteors than the trailing side, and from the orbit and rotational orientation of the Earth, that means that the best time for meteors is between local midnight and noon, and, since we want to observe at night, that means between midnight and a couple of hours before morning twilight begins.

Perseus rises above the NE horizon around 9 PM EDT (at Washington, D.C.’s latitude, ~37°).  By midnight, it will be well above the ENE horizon, and will be favorably placed for post-midnight viewing.  Find Perseus by using the Big Dipper.  One can find the North Star by extending a line from the “pointers,” the two stars at the end of the Dipper’s bowl, in the direction the bend in the Dipper’s handle points.  You can find bright star, Capella, by extending a line atop the bowl of the Dipper away from its handle.  Perseus is reached by “splitting the difference” between Polaris and Capella, about the same distance from the Dipper.  Look between Capella and the “W” shape of the constellation Cassiopeia.

Alas, in 2011, the peak viewing time, the night of August 12/13, will also be a time of the August Full Moon (aka “Moon of the Green Corn”).  Moonlight will blank out the fainter Perseids, thereby reducing significantly the number of meteors expected to be visible. For additional observing tips, visit the Sky and Telescope website.

Dr. Steven H. Williams is the chief of education initiatives in the Education Division of the National Air and Space Museum

Astronomy Night at the Museum

Published by The National Air and Space Museum on July 28, 2011 in Astronomy, Education and space.
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The night opened with few clouds and a bright waxing gibbous moon. Alex and I, interns at the National Air and Space Museum, stood outside with Sean O’Brien, astronomy educator at the Museum and Albert Einstein Planetarium technician, to survey the sky and anticipate the night. This was my first star party at the Museum.

As we set up, the first line of visitors formed outside the door of the Public Observatory waiting for 6 p.m. — opening time. We set up the Tele Vue telescope first. The view was spectacular. Along the terminator, the line between the dark and light sides of the Moon, craters popped between the stark white of the moon and the blue of the sky.

 

Moon

The Moon at 10:50am, April 25, 2011 taken by Katie Moore an Astronomy Educator at National Air and Space Museum using the Tele Vue-85 telescope and Lumenera 2-2 camera.

At 6 p.m., visitors stepped up to take their first close-up look at the Moon in the Tele Vue with Sean’s guidance. Children jumped up and down with excitement while parents assured them that if they study hard they’ll get to work on things like these too. Heads poked through the doorway of the observatory. Many folks were curious about what they would find inside so Alex began to show them around. Solar observing is our main practice during the daylight hours, Wednesday through Saturday. It isn’t often that you have access to equipment that makes it safe to look at the Sun, but we’ve got it!

 

Sun

The Sun taken January 19, 2011 by Erin Braswell, using the 100mm Lunt Hydrogen-alpha telescope in the Public Observatory.

Alex went over the Museum’s Solar observation methods and displayed pictures the observatory has taken of the Sun. The clouds played with us all throughout the night by jumping around and in front of our targets. Often I would ask the crowd to blow in the same direction with me so perhaps we could get those pesky clouds to move just a bit. Still, it did not dampen the spirit of everyone that waited.

Noah, another Museum intern, arrived and we set up the Celestron C-11 telescope on the Moon. The line split into three. One to hear Alex speak about Solar observing, one to look at the Moon through the Tele Vue, and one to look through the 11-inch Celestron that Noah manned. I ran from telescope to telescope making sure each had a target and each was in focus.  Occasionally we would exchange eyepieces to see if we could get a better view.

As the Sun set we began to keep an eye out for Saturn. Then the clouds split and Saturn shined out! I ran into the observatory ready to switch the 16” Boller & Chivens (B&C) telescope from close-ups of the now dark Moon craters to the bright point of the ringed planet. After a bit of searching the planet swam into view and the beauty of the rings and moons was thrilling. Quickly, Alex and I passed the update down the line and cheering floated in through the observatory door. Alex and Rick, a Museum volunteer, took over inside the observatory to help visitors see what they had been waiting for since we opened.

 

Observatory

Lines curled around the side of the building as many excited visitors waited to see Saturn, the Moon, and even Albireo. Photo by Ameé J. Salois.

Next I went to check on Noah and the Celestron telescope. After some minutes and some growling at the clouds we had Saturn in our view as well. This line cheered as well and people filed past excitedly bouncing in front of the eyepiece the minute they glimpsed the beauty of the rings. One fellow told me that tonight he came to have his first view of the iconic planet and he didn’t mind waiting the whole night to fulfill his dream. Later, he told me that he wasn’t disappointed. The night ended with a search for Albireo, a binary star iconic because of its bright blue and gold coloring.

 

Albireo

Albireo. Photo by Rachel Wilkerson and Ameé J. Salois taken on the 36” telescope at the McDonald Observatory.

Sean began looking through the Tele Vue and called me over to help. After some quick searching I had it in my sight! Sean tightened the telescope mount and we centered and focused the image. Next, we changed the eyepiece, but when I pushed it in the mount jerked and the stars were lost. The search began again! This time was successful and the last visitors were pleased to see the bright sparkling of such a unique binary star.

Finally, we said goodnight and the visitors wandered away still looking up and wondering about what else was hidden in that dark sky. We had more than 300 visitors and they looked through the telescopes more than 870 times. It was a thrilling night with many telescope adventures and many new experiences.

Joe DePasquale of Chandra and Smithsonian Astrophysical Observatory (SAO) visited with us and put together a fabulous video summation of our adventures.

Ameé Salois is an astronomy education intern for the National Air and Space Museum this summer.

From Earth to the Solar System

Published by The National Air and Space Museum on June 17, 2011 in Astronomy, Education, Exhibitions and space.
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For the month of June, 30 beautiful images of the solar system are on display on the terrace by the Independence Avenue entrance.  They are part of the From Earth to the Solar System exhibition developed by the Smithsonian Astrophysical Observatory/Chandra with the NASA Astrobiology Institute.

 

Titan

The Mysterious Titan: A Moon of Saturn. This moon may hold the answers to other forms of life. Take "A Myriad of Moons Tour" and learn about how it differs from our own planet’s development.

Make connections between our home planet and the rest of our solar system and take an exciting journey from the soil of our planet to the far reaches of cold space. If you aren’t able to make it to the National Mall this month to see the exhibition, a preview is available online, and it will be traveling around the world over the next year.

The amazing images in this exhibition show our efforts to explore other worlds to uncover their secrets. Let’s take a quick tour. Starting with our understanding of the Earth and moving outwards, we apply this knowledge to each world we encounter opening a new window to the limits of our solar system. We begin our investigation with Australian stromatolites, ancient rock structures created by microbes. Next, studies at Mono Lake, CA have revealed a different possibility that life can sprout from unexpected sources such as arsenic. These examples provide two points of reference when studying solar system objects. Titan, compared to an early Earth, may be the home to methane/ethane-based organisms similar to the organisms at Mono Lake. These are only a few connections. More exploration and study reveals ever-increasing intrigue existing between our own experiences on Earth and the many diverse planets, moons, and other bodies within our solar system.

Each weekday of June, we will offer two 15-minute tours at 9:40am and 9:45am. Take a tour about the theme Cosmic Weather and find out about other solar system bodies with seasons. Created and presented by intern Lauren Bittle, this tour discusses the connection between atmosphere and weather on Earth as well as throughout the solar system. Highlights of this tour include solar activity, volcanic Io, and the great storms of the solar system. What would our moon look like if it were covered in volcanoes? Take the A Myriad of Moons tour, created and presented by intern Ameé Salois, and learn the answer, along with many other facts about the diversity of moons in the solar system. Highlights of the tour include investigations into our own Moon; Io and Europa, moons of Jupiter; and Titan and Iapetus, moons of Saturn.

 

Lauren Bittle

Lauren Bittle visits her favorite moon, Io, on the "Cosmic Weather" tour.

Please come join us for one or both of these exciting journeys through the solar system.

 

Ameé Salois

Find out about ice skating on Europa in "A Myriad of Moons" tour by Ameé Salois.

 

From Earth to the Solar System is a continuation of the 2009 exhibition From the Earth to the Universe, created for the International Year of Astronomy, which visited the Museum that summer. The National Center for Earth and Space Science Education is helping coordinate exhibit locations.

Lauren Bittle and Ameé Salois are astronomy education interns this summer.

 

 

Transit Authority

Published by The National Air and Space Museum on April 5, 2011 in Astronomy and Education.
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On the morning of March 2, I got an excited text message from fellow astronomy educator Shelley Witte, telling me that the International Space Station (ISS) and Space Shuttle Discovery would be coming very close to transiting the Sun from our position at the National Air and Space Museum’s Public Observatory at exactly 3:08 pm.  A transit is when one object in space passes in front of another object; in this case it was the ISS and Discovery passing in front of the Sun, appearing as a dark shape on the Sun’s disk. She got this information from calsky.com, a website that lets observers know when and where the ISS will be passing overhead at any location, including any encounters with the Sun, Moon, planets, or bright stars.  We were unsure about whether or not we could actually see the transit across the Sun, since we were just outside of the predicted path, but we decided to try our luck.

We have several telescopes, which let through different types of light that highlight different features on the Sun. For the transit of the ISS, we used our Tele Vue-85 refracting telescope equipped with a filter that significantly dims the Sun’s light evenly, letting through the light from the Sun’ surface. Using this filter, we can see sunspots in great detail.

sun

Sunspots through Tele Vue-85

We set up our Sun imaging laptop, telescope, and video camera at about 3:00 pm, and waited for the big moment. Fellow Astronomy Educators Katie Moore, Shelley Witte, and other Museum staff and volunteers eagerly watched a large monitor connected to the laptop displaying a live image of what the video camera could see through the telescope.  We began recording a video at 3:07 pm, and waited. At 3:10 pm, we were still waiting for something to happen, and concluded that the ISS and shuttle Discovery must have been too far away from the Sun after all.

The next Friday, I decided to look more carefully at the video just to make sure that we had not captured anything.  About one minute into the video I saw something streak across the top left corner of the Sun and disappear as quickly as it had come. We HAD caught the ISS and Discovery passing in front of the Sun!  Somehow none of the six people watching in real time had seen it with their own eyes.

I was able to process each frame of the video that caught the ISS streaking across the Sun, and make it into a series of images that shows its progression.  I also processed a nice still image that shows most of the ISS’ silhouette against the bright Sun. Unfortunately you cannot see Discovery, even though it was docked with the ISS at the time of the transit. We were all overjoyed to have captured such a rare and fleeting event!

ISS Transit

This image of the International Space Station transiting the Sun was taken on March 2, 2011 at 3:08 pm from the terrace outside of the Pubic Observatory. The ISS is transiting the Sun to the upper left.

ISS Transit

This series of images shows the ISS moving across the Sun in slow motion, and repeats to allow you to see the details.

Erin Braswell is an astronomy educator in the Public Observatory of the National Air and Space Museum.

Jumping In Tweet First

Published by Vicki Portway on April 3, 2011 in Astronomy, Behind The Scenes, Education and Web & New Media.
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On Saturday, March 19, I was thrilled to participate in the first ever Sun-Earth Day Tweetup organized by the NASA Goddard Spaceflight Center. It was also the first time the Smithsonian officially participated in a Tweetup. The event was a great opportunity to give twitter fans (aka “tweeps”) some face-to-face interaction with our research scientists, curators and educators, and provide some fun hands-on learning that illustrated the Sun-Earth connection.

We had discussed the idea of holding a Tweetup at the National Air and Space Museum for some time, so when Aleya Van Doren at NASA Goddard asked our Museum to participate in the Sun-Earth Day Tweetup, it was  a no-brainer for me and co-host Isabel Lara in our Office of Communications. We jumped at the opportunity to partner with NASA, learn from their experience, and meet some great Twitter fans. Museum educators, scientists, and volunteers were eager to participate as well, and we enlisted two of our social media friends at the Smithsonian, Sarah Banks (National Museum of Natural History) and Sarah Taylor (Public Affairs), to help us host.

On the big day, 100 Tweetup participants and NASA Goddard team members arrived at the Museum before we opened to the public.  Usually, this is a quiet time in the Museum, but that day there was a great deal of activity as staff and volunteers prepared for the Kites of Asia Family Day.  After watching the “3D SUN” IMAX film (as perhaps the first group of theater patrons ever encouraged to use our phones – we had to tweet, after all!), everyone split up into groups and took off to explore learning stations setup around the Museum.

RT JoeCLucas: Watching the surface of the sun in 3D on an IMAX screen. Freaking awesome. #nasatweetup #sed2011

The pace was very fast as we moved through the activities. Educator Dr. Steve Williams described Galileo’s observations of the Sun some 400 years ago, and showed copies of his original drawings, which are in the Smithsonian collection. Participants were able to touch a 4.6 billion year old Allende meteorite, leftover debris from the formation of the solar system. Astronomy curator Dr. David DeVorkin talked about telescopic observations of the Sun made from the Skylab Orbital Workshop in the 1970s, and the legacy of Skylab’s Apollo Telescope Mount in today’s Solar Dynamics Observatory. Planetary geologist Sharon Wilson Purdy described her work on the Mars HiRISE mission and explained the role of the Sun in studying seasonal and global climate change on Mars. Tweeps got a chance to view the Sun through three different telescopes outside by our Public Observatory.  The forecast had been for cloudy skies all week, so we were relieved when Saturday came and the skies were clear. The viewing of sun spots and solar prominences was great!  Our three astronomy educators Katie Moore, Erin Braswell, and Shelley Witte, and volunteer Heather Goss, were all on hand to answer questions.  Tweeps were excited to learn one of the telescopes they were looking through was a real Dobsonian telescope built by amateur astronomer John Dobson in 1988. Everyone was tweeting the experience and sharing photos using the #sed2011 and #NASATweetup hash tags.

RT @chaalz: Just touched a rock that was created before our solar system was created. #NASATweetup #SED2011

A Tweetup participant views the Sun through an original Dobsonian telescope. Photo by Todd Stowell.

RT: @pilotconway: Saw some sun spots. So cool. #sed2011 #nasatweetup

A Tweetup participant looks at the Sun (safely) through a solar safe telescope at our Public Observatory. Photo by Camilla Corona SDO.

Tweetup participants could view solar prominences through two telescopes. This image of the Sun's chromosphere was taken through one of the telescopes at the Public Observatory that day. Image by Shelley Witte.

Last but not least, tweeps took a quick tour of Museum highlights led by our knowledgeable volunteer docents, many of whom are pilots, engineers, or scientists and have had amazing careers in the aviation and space industry. Days before the event, I told them not to worry if the group was looking down at their phones a lot; it just means they’re telling everyone about the cool things they’re learning on their tours!  Participants saw objects representing early powered flight to landing humans on the Moon and beyond, including the 1903 Wright Flyer, Spirit of St. Louis, Moon rock, Apollo 11 Command Module Columbia, and SpaceShipOne.

RT @CG____: Amazing. Only 66 years elapsed between Wright Bros flight and landing on the moon. #NASATweetup @airandspace

RT @adcunningham: Do you want to inspire a kid today? Bring him/her to @airandspace #sed2011 #nastweetup

All of the Tweetup participants were friendly and fun, but I have to say I have a particular fondness for NASA SDO’s BFF Camilla Corona SDO (aka @Camilla_SDO). She was a big hit with tweeps and visitors alike, posing beside many of our most famous objects and tweeting photos and fun historical facts.

Camilla gets ready for a showing of "3D Sun" in the Museum's IMAX theater. Photo by Todd Stowell.

Camilla checks out sun spots on the monitor connected to one of the telescopes at the Public Observatory. Photo by Camilla Corona SDO.

Camilla enjoys the "Space Race" exhibition. Photo by Camilla Corona SDO.

Camilla examines the Moon rock that visitors can touch (rubber chickens too, if they could reach). Photo by Todd Stowell.

The entire morning was buzzing with excitement. There was plenty of sharing going on, not just among the Tweetup participants, but also via @NASA and others who were following on Twitter.  So much so that at one point, we discovered, @airandspace and @Camilla_SDO were trending on Twitter in the DC region. In the end, we all had a great time, learned and shared a lot, and we made a lot of new friends. Before the Tweetup group left to return to NASA Goddard, they posed for a photo outside the Museum.

NASA Goddard Sun Earth Day Tweetup participants and Smithsonian hosts. Photo by Mark Avino.

RT @Smithsonian: Group photo of super fun tweeps who came to @airandspace for the #sed2011 #NASATweetup. Enjoy @nasagoddard! http://ow.ly/i/9kRx

RT @bsettlemyer‎ My fave was probably the solar telescopes. But the description of galileo telescope and drawing was interesting too. #NASATweetup #SED2011

Sarah Banks and I were also able to attend the NASA Goddard portion of the Tweetup, where participants watched a NASA EDGE webcast and toured the NASA Goddard facilities, meeting many of the scientists and engineers working on missions like Solar Dynamics Observatory (@NASA_SDO), Lunar Reconnaissance Orbiter (@LRO_NASA) and more.  The NASA Goddard team produced an amazing event and we were so glad to be a part of it.

What’s next? I’m eager to see the Smithsonian host Tweetups to engage more directly with Twitter followers and provide some great behind-the-scenes access to our experts and collections. My Tweetup co-host Isabel and I are actively planning an official Tweetup at the National Air and Space Museum. Stay tuned and follow @airandspace on Twitter for more info!  Also, look for the Public Observatory to start tweeting soon!

Would you like to participate in a National Air and Space Museum Tweetup?  What would you like to see?  Help us plan by sharing your thoughts!

Vicki Portway is Chair of the Web & New Media Division in Collections and Curatorial Affairs at the National Air and Space Museum.

Ten Events of Great Significance in Space Exploration during the Twenty-first Century’s First Decade

Published by The National Air and Space Museum on December 30, 2010 in Astronomy, History, On View at the Museum and space.
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As the first decade of the twenty-first century comes to a close—I know that one could make the case that the first decade ended in 2009 but we had this argument during Y2K and I’m not going to rehash it here—what might we consider the ten most important events in space exploration and discovery? Everyone is free to come up with their own lists, but here is mine. These are in no particular order, at least it is not a countdown, and it is weighted toward recent acquisitions at the National Air and Space Museum. What would your list look like?

•   SpaceShipOne, June 21, 2004, September 29, 2004, and October 4, 2004: Launched from its White Knight mothership, the rocket-powered SpaceShipOne and its pilot ascended just beyond the atmosphere, arced through space (but not into orbit), then glided safely back to Earth. The three flights of SpaceShipOne represented the first times in which a privately-developed spacecraft reached space. The flights were part of the Ansari X-Prize competition to develop a robust and reliable piloted space vehicle that could offer space tourism to a broad set of participants. Based on this success, prospects for suborbital space tourism are expanding as successor vehicles are being built. SpaceShipOne is on display in the National Air and Space Museum’s “Milestones of Flight” exhibition.

SpaceShipOne

•    Mars Exploration Rovers, 2004-Present: On January 3, 2004, the “Spirit” rover landed on Mars in Gusev crater, followed on January 25 by “Opportunity” reaching the Sinus Meridiani region, halfway around the planet from its twin. Since that time, both rovers have been operating on the Martian surface and returning stunning scientific findings that are restructuring our knowledge of the red planet. For one, we now know that Mars was once a watery world, and that water may yet be under its surface. This discovery has profound consequences for the possibilities of life having once been there. A mockup of the Mars Exploration Rover is on display in the National Air and Space Museum’s “Exploring the Planets” exhibition.

Mars Exploration Rover (Image courtesy NASA/JPL)

•    Stardust Comet Sample Return Mission, 1999-2006, extended mission, on-going: Stardust was the first U.S. space mission dedicated solely to returning extraterrestrial material from beyond the Moon. It collected samples from Comet Wild 2 and interstellar dust. Launched in 1999, it returned to Earth seven years later, parachuting to a landing in the Utah desert in 2006. The Stardust canister containing samples was sealed in an exterior shell that protected them from the heat of reentry. The material Stardust returned may date from the formation of the solar system. Scientific studies of the samples are altering our understanding of the universe. One major discovery is that ice-rich comets, the coldest and most distant bodies in the solar system, also contain fragments of materials. This return capsule is on display in the National Air and Space Museum’s “Milestones of Flight” exhibition.

Stardust Return Capsule on display in "Milestones of Flight"

•    Columbia Accident, 2003, and return to flight, 2005: The tragedy of STS-107 on February 1, 2003, cannot be overemphasized. It led to a stand down of the Space Shuttle program for more than two years, a hiatus on most construction for the International Space Station, and the decision to retire the shuttle by the end of the decade. The loss of the crew of seven, including international astronauts, was traumatic. The return to flight with STS-114 on July 26, 2005, brought a return to activity for the U.S. human spaceflight program, but the imminent retirement of the Space Shuttle opens questions about how the U.S. will undertake human activities in space. The Space Shuttle program is a major focus of the “Moving Beyond Earth” exhibition at the National Air and Space Museum.

Space Shuttle Discovery Launches on Return to Flight mission STS-114, July 26, 2005. (Image courtesy NASA/KSC)

•    Building of International Space Station (ISS), 1998-2009: With the first elements launched and joined in orbit in 1998, the building of ISS has consumed most of the human space missions of both the United States and Russia for the last decade. Since the occupation of the Expedition One crew to ISS—William M. (Bill) Shepherd, Yuri Pavlovich Gidzenko, and Sergei K. Krikalev—in 2001 there has been a crew of between two and six aboard the station throughout the decade. The ISS is a major focus of the “Moving Beyond Earth” exhibition at the National Air and Space Museum.

International Space Station (ISS) in August of 2001. Photographed from the Shuttle Orbiter Discovery (STS-105) after separating from the ISS. (Image courtesy NASA/MSFC)

•    Discovery of Extrasolar Planets, 1995-present: The first planet discovered around another star was announced on October 6, 1995, and since that time 358 extrasolar planets have been discovered. Although no Earth-like planets have been discovered yet, the prospects seem good for discovery in the next few years. Imagine the excitement of such a discovery? Information about cosmology, astronomy, and astrophysics is available in the National Air and Space Museum’s “Explore the Universe” exhibition.

Artists concept of an extrasolar planet. (Image courtesy NASA/STScI)

•    Near Earth Asteroid Rendezvous (NEAR) Shoemaker Mission, 1996-2001: NEAR Shoemaker was launched on February 17, 1996, journeyed to the Mathilde asteroid for a flyby, and then landed on the Asteroid 433 Eros on February 12, 2001, while transmitting 69 close-up images of the surface during its final descent. It was the first spacecraft mission specifically designed to study an asteroid. We would really like to collect NEAR Shoemaker for the National Air and Space Museum, but that will have to await a return to Asteroid 433 Eros with capability to return cargo. I probably won’t see this in my lifetime. There is more information on asteroids and their exploration in the National Air and Space Museum’s “Exploring the Planets” exhibition.

433 Eros (Image courtesy JHU/APL)

Last image of 433 Eros sent back from NEAR Shoemaker before it landed. (Image courtesy JHU/APL)

•    Chandra X-Ray Observatory, 1999-Present: Since its launch on July 23, 1999, the Chandra X-ray Observatory has engaged in X-ray astronomy of the universe, taking its place in the fleet of what NASA calls its “Great Observatories” program. Designed to observe X-rays from high-energy regions of the universe, such as the remnants of exploded stars and even particles up to the last second before they fall into a black hole, Chandra has greatly enhanced our understanding of the origin and evolution of the universe. There is a Chandra 1/5-scale model in the National Air and Space Museum’s “Explore the Universe” exhibition.

1/5-scale model of Chandra X-ray Observatory hangs in "Explore The Universe"

•    Hubble Servicing Missions, STS-109 (2002), STS-125 (2009): The Hubble Space Telescope is acclaimed as one of the most significant astronomical instruments in history. First deployed in 1990, it has been serviced five times by astronauts visiting it aboard the Space Shuttle. These missions have extended its service life, and the most recent in 2009 appears to have extended its capabilities for the better part of the next decade. The structural dynamics test article for the Hubble Space Telescope is on display in the “Space Race” exhibition at the National Air and Space Museum. During that last servicing mission, NASA removed the Corrective Optics Space Telescope Axial Replacement (COSTAR) and it is on display in the National Air and Space Museum’s “Moving Beyond Earth” exhibition.

Hubble Test Telescope in "Space Race"

COSTAR

•    Shenzou V, 2003: Until 2003 only two nations had sent humans into space. On October 15-16, 2003, China joined Russia and United States in that exclusive club when taikonaut Yang Liwei completed 14 orbits of the Earth. The trip into space started when the Long March rocket carrying Yang in the Shenzhou V capsule blasted off from the Jiuquan launch center. The National Air and Space Museum looks forward to the prospect of displaying objects associated with the Chinese space program.

I could have offered several other events for this list—the completion of the Milstar constellation, the advance of GPS into everyday life, the launch of Falcon 9 with its Dragon capsule, and the recognition of John Mather and George Smoot with the Nobel Prize for their elucidation of the Big Bang theory with data from the Cosmic Background Explore—all come to mind. I invite others to offer their own lists of significant space events in the first decade of the twenty-first century.

Roger D. Launius is senior curator in the Space History Division of the National Air and Space Museum.

Imaging the Lunar Eclipse

Published by The National Air and Space Museum on December 21, 2010 in Astronomy, Education and space.
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I was pleasantly surprised when the clouds rolled out and the weather turned out to be favorable for the total lunar eclipse last night!  After work, I went home for a quick nap and put on layers and layers of clothing to help me brave the cold on the eve of the winter solstice.  Friends and coworkers told me I was crazy to come back to work at midnight for the eclipse, especially with the temperatures predicted to be in the 20s.  But the clear skies, which have been hard to come by so far this month, were more than this astronomy educator could resist.

So I met fellow astronomy educator Erin Braswell at National Air and Space Museum’s Public Observatory at 1 a.m. to begin preparations for a night of observing and imaging the lunar eclipse.  Our goal was twofold: to experience the eclipse for ourselves, and to capture it to share with our colleagues and visitors.

The 16-inch Boller and Chivens which is the main telescope at the Public Observatory, is a very high-powered telescope, great for seeing the tiny details of the Moon’s craters and other features. However, it magnifies too much to see the entire Moon in one shot so isn’t a great choice for eclipse viewing or imaging. Instead, we used the Public Observatory’s TeleVue-85 refracting telescope along with a Lumenera 2-0 color camera and a Lumenera 2-2 monochromatic camera.

eclipse

Lunar eclipse seen from The National Air and Space Museum's Public Observatory on the morning of December 21, 2010. Photos by Erin Braswell and Katie Moore.

The photograph, above, will give you a quick snapshot of our experience.  If you observed the eclipse, you might notice that the photo does not do it justice. The human eye is much more capable of seeing a range of details and colors on the bright and the eclipsed portions of the Moon, while the camera can only detect one part at a time.  In reality, the “dark” portion of the Moon is still easily visible to the naked eye, although noticeably fainter than normal.  Our cameras only capture, the brighter, uneclipsed portions of the Moon during the partial phases. During totality, they capture the fainter, eclipsed Moon.  In addition, the color is more vivid to the naked eye, during totality.

As predicted, during totality, the Moon was not uniform in brightness – it was slightly dimmer at the bottom, which was closer to the center of the Earth’s shadow.  Also, since the Moon didn’t pass through the middle of the Earth’s umbra, the eclipse doesn’t progress straight across the Moon.

The things I most enjoy about lunar eclipses are seeing such a familiar object as the Moon take on an unusual appearance,  and thinking about how our closest celestial neighbors are arranged to make it happen.  The Sun’s rays usually illuminate the Moon directly, but during a lunar eclipse, the Earth gets in the way.  This causes the partial stages of the eclipse.  Here you can rediscover that the Earth is a spherical object when watching the curved shadow of the Earth moving across the Moon! Then, during totality, the Moon is illuminated by sunlight that seeps through the Earth’s atmosphere, giving it the fainter, reddish glow.  You can almost feel the heavens line up!

Did you photograph the total lunar eclipse? We’d love to see the results! Upload your images to the Public Observatory Project’s group page on Flickr.

Katie Moore is an astronomy educator at the National Air and Space Museum

Total Lunar Eclipse

Published by The National Air and Space Museum on December 17, 2010 in Astronomy and Education.
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The Moon is one of the most easily recognized celestial objects and arguably the easiest one to observe. It is simple to view the changing phases from day to day, with your naked eyes. Binoculars or a telescope will reveal countless craters, ancient lava flows, and other intriguing lunar features. Of the handful of thrilling astronomical events a person can witness in their lifetime, such as meteor showers, planetary transits and oppositions and auroras, solar and lunar eclipses are a must-see.

During the waning hours of December 20th and into the early hours of December 21st, people in North America will have the chance to witness a total lunar eclipse. A total lunar eclipse occurs when the Sun, Earth, and Moon are precisely aligned and the Moon passes into the shadow of the Earth. In other words, the Earth is preventing sunlight from reaching the Moon. Although an eclipsed Moon is always full, a lunar eclipse will not occur every time there is a full Moon since the Moon’s orbit is slightly tilted compared to the plane in which Earth orbits the Sun. When the Moon reaches one of the two points in its orbit where it lines up exactly with the Sun and the Earth, either a solar or lunar eclipse will occur.

eclipse diagram

This shows the geometry of a lunar eclipse. When the Sun, Earth, and Moon, are precisely aligned, a lunar eclipse will occur. During an eclipse the Earth blocks sunlight from reaching the Moon. Earth creates two shadows: the outer, pale shadow called the penumbra, and the dark, inner shadow called the umbra. The eclipse is noticeable once the Moon enters the umbra.

A lunar eclipse is much easier to observe than a solar eclipse.  To view a solar eclipse, one has to travel to a very specific location on Earth. For a lunar eclipse, anyone located on the night side of the Earth has the opportunity to observe it. North America will have the best seat in the house for this total lunar eclipse. Provided they have clear skies, viewers should be able to see the entire eclipse from start to finish. Observers in East Asia, Australia, and New Zealand will see the Moon rising during the eclipse while those in Europe, West Africa, and South America will see the Moon set during the eclipse.

To watch a lunar eclipse you don’t need to use a telescope or any special equipment; simply go outside and enjoy the view. The duration of this total lunar eclipse is approximately four and half hours. If you don’t want to be extremely tired at work or school on Tuesday by staying up for the entire event, you can still see different stages of the eclipse in just over an hours’ time. On the east coast of the United States, the lunar eclipse officially begins around 1 am on the morning of December 21st. However, the exciting part of the eclipse won’t begin until a half hour later.

eclipse sequence

This is a sequence of images taken and arranged by amateur astronomer, Fred Espenak. During a total lunar eclipse, viewers will see the shadow of the Earth slowly move across the surface of the Moon, covering it. Totality occurs when the Moon is fully covered. After totality, the Moon slowly moves out of Earth's shadow. Courtesy of Fred Espenak.

A total lunar eclipse begins when the Moon enters the pale, outer portion of the Earth’s shadow, known as the penumbra. This causes a very subtle darkening of the Moon which is almost undetectable. The umbra is Earth’s dark, inner shadow where no direct sunlight reaches. When the Moon moves into the umbra, the partial eclipse begins, and you will begin to see a dark, curved shadow creep across the lunar surface. Partial eclipse begins at 1:33 a.m. on December 21st for east coast viewers. Totality begins at 2:41 a.m. EST when the umbra has completely engulfed the Moon.

totality

During totality, the Moon is still visible. Sunlight passing through Earth's atmosphere projects itself onto the lunar surface and casts it in an orange or reddish glow. Courtesy of Fred Espenak.

Despite not receiving any direct sunlight, the Moon will still be visible during totality, cast in an orange or reddish glow. This is due to scattered sunlight passing through Earth’s atmosphere and projecting onto the Moon. You have most likely seen this type of scattering of sunlight during brilliantly colored sunrises and sunsets. The color of the Moon during totality will depend on the clarity of the atmosphere during the time of the eclipse. If it’s clear, the Moon will have an orange tint. However, if there’s enough dust in the atmosphere (like from a volcanic eruption), the Moon might appear dark red, grey, or a reddish black.

lunar eclipse diagram

This diagram shows the progression of the total lunar eclipse on December 20th and December 21st, 2010. Each number corresponds with the beginning of a specific stage in the eclipse. 1) Partial eclipse begins 2) Total eclipse begins 3) Mid-eclipse 4) Total eclipse ends 5) Partial eclipse ends. Moon images courtesy of Nathan S. Barrow. (Diagram created by Shelley Witte)

Totality will last 72 minutes and then the Moon will start to reemerge from the umbra — replaying the eclipse events in reverse. If you don’t have enough time or energy to watch the eclipse in its entirety, I recommend watching from partial eclipse until totality or vice versa. Check the chart below/above to find the times the lunar eclipse is visible from your neck of the woods.

time chart

North America will have a great view of the total lunar eclipse on December 20-21, 2010. Listed here are the times when viewers in the contiguous United States can observe the different stages of the eclipse.

If the skies are favorable during the night of the total lunar eclipse, take the opportunity to witness a fascinating celestial phenomenon; if you live in North America you won’t get to watch another one like this until April of 2014!

Planning on photographing the total lunar eclipse? We’d love to see the results! Upload your images to the Public Observatory Project’s group page on Flickr.

To see more eclipse imagery from Fred Espenak, please visit MrEclipse.com.

Shelley Witte is an astronomy educator at the National Air and Space Museum.