Once in a Blue Moon
Cover Photo Credit: Chris Smith
For decades NASA’s plans for human space exploration have focused on Mars as the preeminent target. However, in December 2017, the Trump administration issued a national policy directive through its freshly reconstituted Space Council calling for a return to the Moon—not just with Apollo-style landings, but “for long-term exploration and utilization.” Over the next couple decades, NASA’s efforts may focus on the establishment of a lunar base in the style of Antarctic research centers or the International Space Station—continuously staffed but relying on supplies from Earth.But there are those who look to the Moon as a place where humanity will found an independent, self-sufficient existence.
The rationale goes beyond George Mallory’s famous quip about his reason for climbing Mount Everest:“Because it’s there.” Instead of being a goal in and of itself, lunar exploration is seen as a path to the extraction of valuable and even unique resources. Perhaps chief among these is helium-3, a light, non-radioactive isotope of helium that is implanted into the lunar surface via the solar wind and could be readily mined from the lunar soil (or regolith). Helium-3 is a potential source of clean nuclear fusion energy once such reactor technology is developed.
Water is another resource that is plentiful on the Moon—surprisingly so, given the stark, airless environment, which is subject nearly everywhere to enormous temperature extremes. In addition to ice deposits found in permanently shadowed (and thus extremely cold) polar craters, vast stretches of the lunar surface have been found to contain tiny concentrations of water outgassed from the Moon’s interior or generated in interactions with the solar wind. Water could be conventionally mined from the poles or simply baked out of the lunar regolith by roving, robotic ovens. As a resource, water is incredibly useful for several reasons: as liquid for human consumption, broken into its constituent elements for oxygen for breathing, and for the combination of hydrogen and oxygen as rocket fuel.
Even more ambitious visionaries see a future in which human existence on the Moon is not limited to isolated, enclosed habitats, but one in which the whole environment of the Moon has been altered or “terraformed” into a small version of Earth. The generation of an oxygen atmosphere thick enough to support life could be accomplished by impacting hundreds of comets the size of Halley’s Comet onto the Moon—a task impossible with current technology, but perfectly feasible given straightforward physics. Although the Moon’s low gravity means that oxygen atoms would escape into space far more readily than from Earth and any atmosphere would only be temporary, the timescale for such loss could still extend into millions of years. This is short on geological scales, explaining the Moon’s current airless state, but long in personal human terms.
Indeed, there is evidence that the Moon may have possessed a short- lived atmosphere billions of years ago. Several rocks recovered from the Moon by Apollo 16 astronauts were found to contain bits of natural iron that had somehow rusted—a process requiring the presence of oxygen and liquid water. Models of cometary impacts and volcanic activity suggest that temporary lunar atmospheres may have been formed many times over the past four billion years.
Whatever the scope of future human activity on the Moon, it is likely that someday we will return, and it may just be that this time it will be forever.
Adler Skywatch: January 2019
Bright stars and planets, meteors, an eclipse, a “Supermoon,” and a close approach by the Sun are all expected during January 2019.
In evening twilight this month, the planet Mars is high in the southern skies. The night of the 12th, it appears near a waxing crescent Moon. Each evening Mars appears higher in the sky than the night before; but it also gets slightly dimmer each night, as it moves further from Earth after its close approach last summer. By about 10:00 pm CT, Mars is very low in the west.
The rest of the month’s planetary viewing occurs during early-morning darkness. The two brightest planets, Venus and Jupiter, are above the southeast horizon by 6:00 am CT. Venus is the brighter of the two—though both are brighter than any of the stars in the night sky. From the 1st through the 24th, Venus appears higher than Jupiter. But on the 25th and 26th they appear at about the same altitude. By the 28th Jupiter appears higher than Venus. A waning crescent Moon appears between the two planets on the 31st.
The planets Mercury and Saturn appear so close to the Sun this month that they are difficult if not impossible to view.
Perihelion, when the Sun is closest to Earth for the year, occurs on the 2nd, at 11:19 pm CT. At perihelion, Earth is about 91.4 million miles from the Sun, which is about 3 million miles closer than it is at its furthest, which occurs in early July.
Also in January, the annual Quadrantids Meteor Shower peaks the night of the 3rd and morning of the 4th. From very dark, very clear skies, a peak of about 40 meteors per hour is expected. This year the waning crescent Moon doesn’t rise until morning twilight on the 4th, so it won’t interfere with the sky’s darkness. The Quadrantids appear to radiate from the constellation Boötes, which rises in the northeast around midnight Central time—but the meteors can appear anywhere in the sky. No special equipment is needed—just dress warmly for the weather, and look up!
The month’s biggest astronomical event is the night of the 20th, when a total lunar eclipse is visible from most of North and South America. In the Chicago area, the partial phase of the eclipse starts about 9:34 pm Central time, as the Moon slips into Earth’s shadow. Totality, when the Moon is entirely within Earth’s shadow, begins at 10:41 pm. During totality the Moon is likely to turn a deep reddish color. Totality ends at 11:43 pm; and the partial phase ends at 12:50 am on the 21st. Look now while you can, because this is the last total lunar eclipse anywhere until May 2021.
The 20th is also the night of 2019’s first “Supermoon”—a Full or New Moon near perigee, the point in the Moon’s orbit when it’s closest to Earth. A Supermoon often looks slightly larger than a usual Moon. This year the February and March Full Moons will also be considered Supermoons.
New Moon: January 5th
First Quarter Moon: January 14th
Full Moon: January 20th
Last Quarter Moon: January 27th
Please note: these descriptions are for the Chicago area, using Central time.
A Total Lunar Eclipse
Did you get to see the lunar eclipse this past January right before sunrise? It was tough to see. The Moon was low in the west, and we didn’t get to view the entire eclipse because the Moon set before the eclipse finished. Folks out in the western U.S. got a much better chance to see it than we did since the Moon was higher in the sky for them than it was for us. But on January 20, 2019, if the weather is clear, we’ll be treated to a great lunar show in the sky from start to finish!
A lunar eclipse occurs when the Sun, Earth, and Moon are perfectly aligned. Sunlight falls on Earth, and Earth casts its shadow into space. The Moon’s orbit is tilted a bit with respect to the Earth, so as the Moon orbits Earth, usually the Moon passes a bit above or below the shadow. But, when the Moon passes through the Earth’s shadow, we see the Moon turn brown, red, orange, or gray. This is called a lunar eclipse. If you were standing on the surface of the Moon, the Earth would appear to eclipse the Sun.
The next lunar eclipse visible from the Chicago area will be on January 20, 2019—a Sunday night. The Moon will be in the eastern sky when the eclipse starts at 8:36 pm CST. As it begins to pass into the lighter part of the Earth’s shadow, the color of the Moon will start to change from bright light gray to a progressively deeper tan. Starting at 9:33 pm CST, the Moon will begin to encounter the darker part of the Earth’s shadow and look a bit like a cookie with a bite taken out of it. At 10:41 pm CST, the Moon will be fully within the Earth’s shadow, looking dark red or dark gray. This is called totality. Totality ends at 11:43 pm CST, and the Earth exits the darker part of the Earth’s shadow at 12:50 am CST on January 21. The Moon fully exits the lighter part of the Earth’s shadow at 1:48 am CST on January 21.
If it is clear out and you are away from tall buildings and trees, you should have no trouble spotting the eclipse. The Moon will be high in the sky to the east, southeast, and south. Remember: It will be January, so if it is clear out, it may be VERY cold. Don’t forget to bundle up warmly and grab some hot cocoa or coffee!
It takes a great deal of confidence to make our visions reality. I understand this firsthand because, like so many people, I’ve had ambitious ideas, but had no idea how to make them come to fruition.
In 2014, I had the opportunity to update the exhibit about Captain Jim Lovell’s life and contributions to getting humanity to the Moon and back. Working on this exhibit would be a massive opportunity for me professionally, and the pressure was on. At the time, it felt like a daunting task with limitless possibilities, but no clear way to begin. I took inspiration from the man I was researching and decided to take action on my crazy ideas and not to fear failure because failure is part of the process. It would take a year to complete the project, and there were many ups and downs along the way; but in April 2015, ideas that existed only as dreams and crazy ideas became a reality. Mission Moon opened to the public.
Captain Lovell has inspired generations to look up, explore, and achieve the impossible. To commemorate his 90th birthday, we updated Mission Moon by launching Letters to Lovell. We asked you to share how Captain Lovell’s story has encouraged you to pursue your dreams and find new frontiers to explore in a letter-writing campaign. So far, you have shared your dreams and aspirations parallel to Captain Lovell’s boyhood dream of becoming a rocket engineer, launching rockets, and becoming an astronaut. Perhaps people dismissed Captain Lovell’s ambitions as boyhood daydreams—and there indeed was a lot of uncertainty—but like so many of us, Captain Lovell’s drive and willingness to act on opportunities as they presented themselves helped him make his dreams a reality.
What are your dreams? Does your future career currently exist, or will you need to forge a path and open new frontiers? Will you need to engineer the ideas that only exist in your imagination?
Change and infinite possibilities are on the horizon. The way we live, work and relate to one another will be fostered by you. Take inspiration from Captain Lovell: Dream big and don’t let the fear of failure stop you from making your dreams a reality. You will reinvent the world, again and again, and again. Thank you, Captain Lovell, for this amazing legacy.
Adler Staff Star: Meet Yolanda!
Guest Services Shift Supervisor
What do you enjoy the most about working at the Adler?
What I enjoy most about working at the Adler is leading a great team on a daily basis and watching them give our guests memorable experiences.
What is one of your favorite memories from your time at the Adler?
One of my favorite memories at the Adler was our Eclipse 2017 event. It was crazy to see how many people we hosted at once!
Why, in your opinion, is space freaking awesome?
I think space is freaking awesome because we keep discovering new things all the time.
What do you like to do outside the Adler?
I like to go out with friends and do fun activities with them, like going to concerts and checking out new restaurants.
Share one interesting fact about yourself!
I once climbed the pyramids in Mexico!
Sailing to the Moon and Back
This December, we celebrate the 50th anniversary of the Apollo 8 mission to the Moon, one of the most amazing journeys of exploration in human history. This was the first time humans ever ventured away from Earth’s immediate vicinity, and the first time anyone saw both sides of the Moon with their own eyes.
On Christmas Eve of 1968, Apollo 8 astronauts Frank Borman, William Anders, and James Lovell were on the far side of the Moon, out of contact with Earth. A rocket boost was required to enter lunar orbit. Too much of a burn and the spacecraft would crash into the surface. Too little and the crew would be sent into a trajectory that could have made it impossible for them to return home.The maneuver, perhaps the riskiest of the whole mission, was executed perfectly. After a journey of almost a quarter of a million miles, it hit its target: an altitude of about sixty miles above the lunar surface. The success of Apollo 8 lead to the subsequent Apollo missions that landed on the lunar surface.
Leading up to the Moon missions, NASA and its contractors had to address many challenges. Among the biggest: How could a spacecraft be navigated with pinpoint accuracy all the way to the Moon and back?
The earlier Gemini spaceflights of the 1960s tested solutions for space navigation. Lovell also flew on Gemini XII, the final flight of the Gemini program, with astronaut Buzz Aldrin. In the spacecraft was a sextant which Aldrin used to take readings of star positions. Today the Gemini XII spacecraft is displayed at the Adler. You can see where the sextant was stowed on the interior “ceiling” between the two hatches.
Developed after extensive testing, the Apollo navigation systems included celestial navigation based on measuring star positions and radio navigation using signals from Earth. For centuries, navigators have used tools such as sextants and chronometers to determine position. Just like sailing ships, the Apollo spacecraft carried sextants. These worked on the same principles used by historic sextants in the collections of the Adler Planetarium.
During flights to the Moon, an astronaut would maneuver the spacecraft to make a star visible in the sextant, measure the angle between the star and Earth, then enter a code into the computer. James Lovell had primary responsibility for testing the navigation system during Apollo 8. Lovell made more than 70 sextant sightings on the way to the Moon and a similar number on the return journey. Lovell performed more celestial navigation sightings in space than any other person, a mark that stands to this day. By the end of the Apollo 8 mission, both the celestial and radio methods of navigation were in almost perfect agreement.
The journey to the Moon was followed by the crew’s dramatic Christmas Eve reading from the book of Genesis and the “Earthrise” image, one of the most famous photographs ever taken. Later, another rocket burn was required to leave lunar orbit and get back to Earth. To everyone’s relief, the crew made radio contact when they emerged from behind the Moon on the correct trajectory. Lovell reported back to Mission Control, “Please be informed there is a Santa Claus!”
Apollo 8 proved to be a unique turning point for space exploration. It was the last time humans extensively tested traditional celestial navigation techniques in space. For future Apollo missions the ground-based radio positioning took precedence. The space travelers of Apollo 8 expanded the human presence beyond the Earth for the first time. Along the way they briefly navigated in the manner of eighteenth- and nineteenth-century sea captains, connecting their voyage with centuries of human ingenuity and innovation.
The Secret Life of the Sun
The Sun looks pretty boring, right? It’s just a glowing ball in the sky that doesn’t appear to do anything particularly remarkable. But, I’m here to tell you that there’s more to the Sun than meets the naked eye.
The Sun emits light in many different wavelengths. Specialized telescopes can observe the Sun in multiple wavelengths of light, including those not visible with our eyes. This helps scientists to learn about the different processes that occur on the Sun’s surface and in various layers of its atmosphere.
Tangled Magnetic Fields
Observing the Sun in ultraviolet wavelengths reveals giant arches of hot gas extended above the Sun’s surface. These arches trace out loops of extreme magnetic fields that can reach distances up to 10 times the Earth’s diameter above the Sun. On the Sun’s surface, at the base of these arches, are dark Earth-sized regions of intense magnetism called sunspots.
Why should we care about the Sun’s (usually invisible to our eyes) magnetic fields? Frequently, regions of solar magnetism release an enormous amount of stored magnetic energy. Often referred to as solar storms, these explosions accelerate a tangled cloud of magnetic fields and hot gases away from the Sun with an energy equivalent to millions of simultaneous hydrogen bomb detonations. Solar storms can expose astronauts to high levels of radiation, damage communication satellites, and produce electrical surges in our power grid. But, solar storms also produce the aurora–the northern and southern lights.
The Sun’s Magnetic Furnace
The Sun creates all of its magnetic fields from scratch through a process called a dynamo. The Sun’s dynamo converts the energy from the motion of the hot gas in its interior into magnetic fields. To study how the Sun and other stars create their magnetism, I use a branch of physics called magnetohydrodynamics. Using supercomputers, and pencil and paper, I combine the equations of electricity and magnetism and the motion of fluids to understand the Sun’s magnetic furnace. We still do not have a complete theory to describe and predict the Sun’s magnetic behavior, which has an impact on our habitability and technological world. My work is just one important piece of this puzzle.
See it for yourself!
The Sun has a secret magnetic life. This magnetism is created deep in its interior well beyond the reach of telescopes. But, this magnetism reveals itself on and above its surface if we observe it in wavelengths of light hidden from our eyes.
At the Adler Planetarium in our Space Visualization Laboratory, you can see 3D videos of the Sun’s magnetic fields taken from new telescope observations and cutting-edge computer simulations. On cloud-free mornings, you can also catch a glimpse of the Sun’s surface through portable telescopes at the Adler Planetarium or in our Doane Observatory. Maybe you’ll find a sunspot or two. While you’re at it, stop by our historical book collection to see some of Galileo’s first drawings of sunspots. You can also help solar and stellar physicists with their research as a citizen scientist. Join the Zooniverse projects Solar Stormwatch or Protect Our Planet From Solar Storms to help track solar storms through space, or the Variable Star Zoo project to help classify observed brightness variations in stars, occasionally caused by stellar magnetism.
A Holiday Comet?
Have you ever seen a comet in the night sky? I suspect most of the people reading this haven’t. It’s not that there aren’t a lot of comets in the Solar System—more than 5,000 have been discovered so far and several dozen can be spotted using very large telescopes each year—but because most comets are extremely dim and only a handful have brightened enough to overcome our light polluted skies, this makes seeing a comet one of the more rare experiences in astronomy.
This December, Comet 46P/Wirtanen is getting a bit of attention because as of early December, it has become bright enough to be seen using binoculars under dark skies far from city lights. Will it get brighter? Only time will tell.
What, exactly, is a comet? The name “comet” comes from the Latin word “coma,” which means “hair,” the name given because these objects looked very fuzzy & hairy in the sky. A comet is a chunk of mostly various ices, dust, and rock. Comets generally orbit the Sun, some with orbits of just a few years and some with orbits that are much longer than that, like Comet Halley’s 76 year orbit around the Sun, Comet Hale-Bopp’s ~2,500 year orbit, and Comet Hyakutake’s ~70,000 year orbit. Some might visit our neighborhood in the Solar System just once before heading off into the deep-freeze of space. The head, or the ice chunk itself, of a comet can range in size from less than a mile wide to a few tens of miles wide. As a comet approaches the Sun, its ices start to heat up, causing the head of the comet to let loose some of this material. The material streaming away from the head forms the comet’s tail. Comet tails can stretch for millions or even tens of millions of miles, and a comet may have more than one tail.
Comet 46P/Wirtanen (pronounced vir-TUN-nen) orbits our Sun in just over 5 years, and it was discovered by American astronomer Carl Wirtanen in 1948. In December 2018, Comet Wirtanen is passing particularly to Earth, about 7 million miles away, which places this comet among the top 10 closest comets to pass by Earth since 1966. This close distance combined with its predicted brightness has caused amateur astronomers to get a little excited about the possibility of seeing a decently-bright comet.
Comet 46P’s orbit is well known, but its brightness is difficult to predict. Several comets in the past few decades have disappointed us with a brightness—or dimness, actually—that is less than impressive. We don’t know for sure what a comet is going to do when the Sun interacts with it. One extreme example was 2012’s Comet ISON, named for the International Scientific Optical Network (ISON, sometimes pronounced “EYE-sahn”) in Russia that discovered it. Comet ISON passed just over 500,000 miles from the Sun and was going to swing around to be seen in our December 2012 evening skies—and maybe even bright enough for us to spot it from cities! We let ourselves get a bit excited, and we made preliminary plans at the Adler Planetarium to try to spot it after it rounded the Sun, but excitement was soon replaced by utter disappointment as Comet ISON disintegrated after passing close to the Sun. To paraphrase Monty Python: Comet ISON is no more. Comet ISON has ceased to be. Comet ISON is an ex-comet.
Two comets that I mentioned previously did, however, live up to the brightness hype: Comet Hyakutake, named for Yuji Hyakutake (pronounced HYAH-ku-TAH-kay), a Japanese amateur astronomer, and Comet Hale-Bopp, named for Alan Hale and Thomas Bopp, two people who separately discovered it on the same night. Comet Hale-Bopp was discovered in 1995, about two years before it was going to swing past the Earth and Sun. This comet started getting active when it was out near Jupiter’s orbit, which is rare for comets. Yuji Hyakutake discovered his namesake comet in 1996 just a couple months before it was going to pass closest to the Earth and Sun. Comet Hyakutake was dim at first but brightened rapidly, and by the end of March, we could see it from the Adler Planetarium without telescopes or binoculars even under Chicago’s light polluted skies. And just a year later, Comet Hale-Bopp swung by. Both comets were absolutely spectacular.
Below are two pictures that I took of Comet Hyakutake, both from the western suburbs of Chicago. The third picture is of Comet Hale-Bopp, as seen from in front of the Adler Planetarium.
If you missed these comets or if you are too young to remember them, next time you chat with an amateur astronomer who was scanning the skies around that time, ask him or her to tell you about those comets. She or he may gaze wistfully into the distance, with a look that might say, “Will we ever see a comet like that again?”
Will Comet 46P/Wirtanen be bright enough to be seen with just our eyes or could we spot it under light polluted skies? More than likely, light pollution might win out this time, but it won’t stop folks from trying to see it. That’s what makes astronomy fun… getting out and trying to find something yourself!. Behind the scenes at the Adler, we’ve been keeping an eye on reports about this comet for about two2 months now, trying to figure out if it is going to be worth braving December’s cold lakefront weather to attempt to show it to you. Images shared by the astronomy community show a beautiful green comet, but these are very long-exposure images, not how the comet truly appears to our unaided eyes. Recent reports we’ve received from local amateur astronomers suggest that the comet is currently visible under very dark, clear, dry skies, but when you add in a little light pollution or haze, the comet isn’t so easily spotted.
Want to try to find Comet 46P/Wirtanen? Go out where it is VERY dark—far from city lights—and use the map below to pinpoint the comet’s position during December 2018. Use a small telescope or binoculars and look for a faint fuzzy blob. We’ll keep an eye on it here at the Adler, and if it is bright enough, and if the weather cooperates, maybe we’ll be able to get our telescopes out to show it to you. Keep an eye on our social media channels, just in case. And if Comet 46P isn’t the next great comet, then we’ll just sit back, gaze wistfully off into the distance, and think about the time when two beautiful comets graced our Chicago skies.
Navigating to the Moon and Back: Celebrating the 50th Anniversary of Apollo 8
It’s strange to imagine, but humans left the vicinity of the Earth for the first time just 50 years ago this month. The Apollo 8 flight was an incredible feat of exploration that required astronauts to navigate using sextants and radio signals. Highlights from this 6-day mission include the successful (and difficult) placement of the spacecraft into lunar orbit, a live broadcast from the shuttle on Christmas Eve, and the iconic Earthrise photo.
To help celebrate the 50th anniversary of Apollo 8, a group from the Adler Planetarium is in Washington D.C. to share a special object from the Adler’s Collections during public events at the National Cathedral and the National Air and Space Museum.
Tonight, they will attend a celebration of Apollo 8 at the National Cathedral where the flight plan carried to the Moon and back by astronaut Captain James Lovell Jr. will be on display. This treasured artifact typically calls the Adler’s Mission Moon exhibition home, and includes a detailed flight schedule and notes for the famous Bible reading that occurred during the historic Christmas Eve broadcast in 1968.
Captain Lovell himself will be in attendance and you, too, can join the celebration at the National Cathedral tonight at 7:00 pm CT via NASA TV.
Tomorrow, Wednesday, December 12, Adler’s VP for Astronomy and Collections, Dr. Andrew Johnston, will be leading a talk that showcases the flight plan along with other objects of lunar exploration at the National Air and Space Museum. You can catch Andrew’s talk on Facebook Live at 10:00 am CT via the National Air and Space Museum’s Facebook page.
Throughout history, humans have curiously observed and watched the Moon. From observing with only the naked eye to looking through the lenses of high powered telescopes, we have imagined the possibilities. And in 1968, Apollo 8 challenged our understanding of human limitations. No longer was the Moon a distant object in our sky, but a new world we would find ourselves longing to step foot on.
“Relevance of Collections”—the Artefacts meeting comes to Chicago
For more than two decades now, the Artefacts consortium has been promoting an annual meeting that brings together museum professionals and scholars working with scientific and technological collections. This year’s meeting, the 23rd in the series, was hosted by the Adler Planetarium, under the theme “Relevance of Collections.”
During the three days of Artefacts XXIII (Oct. 14-16; see program here), we witnessed a wonderful roll of presentations given by speakers from nine countries and 16 institutions. We saw how overlooked or “sleeping” objects in science and technology museums gain new lives when their stories are researched deeper. Or when we think of them not in terms of success vs. failure, but as material evidence for dynamic processes of inquiry and invention, and personal endeavor. We heard about museum artifacts acquiring new meanings when revisited with the aid of modern technologies—for example, early sound recordings literally being made to speak, revealing their content after decades of silence.
We learned more about the immense potential of digital technologies, be it to engage audiences all over the world with a museum collection through video-gaming, or to rekindle a traditional exhibition project that was hampered by political events, but which came to fruition nonetheless in digital form. Digital images and storytelling tools will never replace the actual artifacts, but they can be a powerful aid in overcoming various kinds of obstacles as we seek to make museum objects ever more visible and accessible.
Art historians and curators shared their views on the intersections and overlaps between art and science collections, which are much more intertwined than the traditional disciplinary divisions followed by cultural institutions may suggest. In fact, the need to go beyond conceptual and institutional boundaries, including within institutions, came across several presentations. It was particularly evident in a session led by staff from the Adler’s collections, citizen science, and visualization teams, which highlighted how important it is to raise awareness for collections among museum staff at large and to foster collaboration across different departments in order to further explore their potential.
In the closing session, we went back to the fundamental issues underlying the whole meeting: what to preserve, what for, for whom? Or, as one the last speakers aptly puts it, “What’s worth preserving?”. There will never be definitive answers to such questions, and it is up to each institution to find the responses that will suit them best. But it’s certainly worth, helpful, and inspiring to debate these issues with colleagues from all over the world in a lively, friendly, and thought-provoking environment, as we experienced at the Adler over the three days of Artefacts XXIII. And one thing is for sure—museum collections will remain relevant as long as the museum community strive to make them meaningful to broader society, and keep on exploring creative ways to do so.
Header image: Cathleen Lewis speaking about the changing meaning of the National Air and Space Museum’s spacesuit collection.