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Space Topics: Planetary AnalogsStars Above, Earth BelowAstronomy and Space Exploration in America's National Parks
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Come See the Milky Way Government posters during the Great Depression urged Americans to visit the national parks and see the wonders of the country. If you know where to look, a visit today can show you the wonders of the Universe. Credit: Tyler Nordgren |
by Tyler Nordgren
Astronomer, University of Redlands
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Denali National Park and Chugach National Forest, Alaska (July 1 – 3, 2007)
Northern climates are where the first signs of global warming are predicted to manifest themselves. In the last century a number of glaciers in Alaskan parks have shown significant recession. I visited Portage Glacier in the Chugach National Forest as well as traveled to Denali National Park in support of my work on planetary atmospheres later at Glacier National Park in Montana.
» July 10, 2007: What Was Once Then, Is Not Now
Rocky Mountain National Park, Colorado (August 8 – 22, 2007)
The tectonic forces which build mountains are one of the four geologic mechanisms which act on a planet’s surface (the others being erosion, volcanism, and impacts). Mountains and mountain ranges of one form or another are found on many planets and moons within the solar system. What are the forces that cause the Rocky Mountains? In what way are they similar to the forces building mountains on other planets and moons? Historically, the best scientific knowledge of mountain and continental formation of the 18th century led early explorers like Lewis and Clark (1804) to grossly underestimate what they would find at the Continental Divide. Sometimes the best scientific ideas, hampered by a lack of initial observations or imagination, lead to spectacular surprises. The discovery of the first planets around other stars is one such example.
» August 12, 2007: Go to the Mountains
» August 23, 2007: Rocky Mountain Night
Sky Park
Grand Teton National Park, Wyoming (August 26 – 29, 2007)
On August 21, 2017, at 11:36 am Mountain Daylight Time, a total solar eclipse
was visible from Grand Teton National Park. What
are eclipses? How can
we predict eclipses so accurately? The defining characteristic of science is
its ability to make accurate predictions. Almost ten years earlier, on August
28, 2007, a total lunar eclipse will be visible from the western United States,
including Grand Teton.
Lunar eclipse over the Grand Tetons Tyler Nordgren captured this lunar eclipse sequence from his campsite in Grand Teton National Park on the night of August 29, 2007. He took an exposure of the moon every 10 minutes until it disappeared and the sun lit up the mountains with alpenglow. Credit: Tyler Nordgren |
Glacier National Park, Montana (September 1 – 8, 2007)
Current research using NASA spacecraft shows both Mars and Venus once had very different climates than they do today. For Mars, the evidence is contained in the rocks and landforms visible on the surface and from space. For Venus, much of what we know about the “greenhouse effect” on Earth comes from our observations of a “runaway” effect in Venus’ atmosphere. Glaciers on Earth are one way in which we learn about the history of climate change on Earth. The shapes of valleys and other geological evidence point to the recent history of glaciation over much of North America. Similar features on Mars have been found in imagery returned from orbit. Much work has gone into how Mars’ climate changed and whether or not it was ever warm and wet enough to support life. I propose to use knowledge of glaciers in the Rocky Mountains as an introductory tool for exploring past climate changes on both planets. Venus’ climate, on the other hand, offers a perspective on one possible fate for Earth’s climate. A number of lines of study show the Earth has begun to warm as a result of man-made changes to our atmosphere. A number of the scientists most convinced of this are NASA scientists with backgrounds studying Venus’ atmosphere. Recent studies of declining glacier fields have been cited as strong indicators of the Earth’s warming. Again, using glaciers to study our atmosphere’s past serves as a barometer for understanding its future.
» September 7, 2007: Ex-Glacier Park
Acadia National Park, Maine (September 20 – October 16, 2007)
Ocean tides are one of the astronomical phenomena with which the public is most familiar but yet is least aware has an astronomical cause. In addition to the height of the ocean, tidal forces are responsible for many phenomena including why most moons (including our own) always keep the same face towards their parent planet. Tidal forces acting on many moons of the outer solar system result in a surprising degree of activity. Tidal forces acting on Jupiter’s moon Io, and Saturn’s moon Enceladus, produce volcanoes of rock and ice, respectively. On Europa, however, tidal forces from Jupiter are believed to have melted the subsurface ice resulting in an “ocean planet” covered by a potentially thin layer of ice. From a biological perspective, Europa is now viewed one of the most likely spots in the solar system, other than the Earth, where life may have arisen. Many of NASA’s plans for astrobiology now center on Europa. While the effects of tides may be viewed in many places, Acadia is one of the few parks along the East Coast, and is one of the top ten most frequently visited parks in the nation.
» September 24, 2007: Out and About with
the Tide
» October 10, 2007: An Island of Stars
Great Smoky Mountains National Park, North Carolina (October 17 – 25, 2007)
In many parts of the eastern United States, fall wouldn’t be fall without the myriad colors of changing leaves sweeping across valleys and hillsides. Seasons occur on every planet with a rotation axis tilted with respect to the Sun. Mars, like Earth, is tilted to the Sun by an angle of 23 degrees. Uranus is tilted by a little over 90 degrees and so in summer has one hemisphere pointed directly at the Sun, while the other hemisphere is in perpetual darkness. Current theory says that these axial tilts may be the result of enormous planetary impacts early in the formation of the solar system. Impacts are also believed to be responsible for the formation of the moon, extinction of the dinosaurs, and to represent a danger to us still. Using the seasons as a starting point I will present the evidence supporting the need for continued monitoring of the skies for potential impact hazards.
» October 25, 2007: Smoke and Seasons
A Thousand Years of Astronomy
Petroglyphs of the moon, supernova, and a comet (bottom wall) in Chaco Culture National Historic Park in northwestern New Mexico attest to the importance of astronomy to cultures over the ages. Credit: Tyler Nordgren |
Chaco Culture National Historic Park, New Mexico (December 1 – 22, 2007)
The ancestors of today’s Puebloan people, who inhabited the American southwest, had a rich astronomical tradition that can still be seen to this day. The large numbers of astronomical alignments that appear to have been built into the Great Houses are strong evidence of the importance the Sun and Moon played in their ceremonial life. The sun dagger petroglyph on Fajada Butte speaks to the observational sophistication of the Chacoans, while the pictographs of a supernova and possible comet and a potential solar eclipse petroglyph all point to the importance they placed on monitoring the sky for unexpected events. The culture centered in Chaco Canyon had an obvious connection to the sun and sky. Today, many people look for a similar connection through mysticism and pseudoscience. The science of astronomy gives a much more direct connection through the lives of stars since, in the words of the late Carl Sagan, we are all “star stuff.”
» December 9, 2007: Astronomy National
Park
» January 3, 2008: The Center of the Universe
The Milky Way Above Lipan Point
The Milky Way in Cygnus is still faintly visible over the western rim of the Grand Canyon. Lights from distant cities like Las Vegas light the undersides of clouds along the horizon. Credit: Tyler Nordgren |
Grand Canyon National Park, Arizona (January 6 – 27, 2008)
The erosion that has created the Grand Canyon is one of the four primary physical forces which shape the planets and moons in our solar system (tectonism, volcanism, and impacts, are the other three). How do canyons seen on other planets and moons in the solar system compare with the Grand Canyon? In particular, a number of canyon systems on Mars appear to be carved by flowing water. How do these systems and our understanding of their origins compare to the origin of the Grand Canyon? From a cultural perspective, every people has had its own creation stories or myths. The nearby Hopi tell that people first entered the world through a hole in the ground where the Colorado and Little Colorado rivers meet within the Grand Canyon. In addition to my geological research I plan to research creation stories of the Native American peoples living in and around the Grand Canyon area. Because the forces which excavate the Grand Canyon are ones that work slowly over very long periods of time, the Grand Canyon itself serves as an excellent analog for the scientific story of the creation of the universe, the planet, and life itself, all of which depend on understanding the slow process of change over billions of years.
» January 21, 2008: The Long Road Back
from Long Ago
Cold Faithful Planetary Park
Come see the geysers! Watch out for the campfires. Future park poster printed by the U.S. Department of the Exterior. Credit: Tyler Nordgren |
Yellowstone National Park, Wyoming (February 3 – 24, 2008)
Yellowstone has many connections to astronomy and the night sky. First, Yellowstone
has been found by Chad Moore’s observations to be one of the 10 darkest
parks in the nation. Like similarly dark parks, stargazing and appreciation
of the night sky are an important component to a significant number of park
visitors. Secondly, the volcanism at work under the park which gives rise to
the many famous geological features found there are excellent analogues to
features found on other volcanically active bodies in the solar system. In
August 2004 a meeting of NASA astronomers studying volcanoes on Jupiter's
moon Io visited Yellowstone expressly because of this connection. In addition, NASA
scientists in the field of astrobiology regard the thermophiles living within
the hydrothermal features at Yellowstone as important laboratories for possible
biologies on other planets. Lastly, Yellowstone’s history and creation
as a national park through early exploration by scientific teams and artists
serves as a powerful analogy for NASA’s current scientific exploration
of the solar system.
The Milky Way and Tyler Nordgren
At 3:30 am I watch the Galaxy rise. Before me is the center of the Galaxy, 8,500 parsecs (30 thousand light years) away. To my left is Cygnus, the direction the Sun travels as it orbits the Galactic center. To my right is the direction from which we have traveled. The Sun makes one complete orbit every 250 million years or so. Notice the Milky Way looks dim and reddened near the horizon. This is due to dust in our atmosphere, just as the light of the rising or setting sun is red and dim. Now, however, it is the light of a billion sunrises. Credit: Tyler Nordgren |
» February 14, 2008: Cold Faithful
Big Bend National Park, Texas (March 9 - 14, 2008)
Big Bend is one of the largest, yet least visited parks in the continental United States. It is also one of the darkest. In late spring, a park visitor to Big Bend can watch as the winter Milky Way sets and summer Milky Way rises during the middle of the night. At the moment between these two events, the Milky Way wraps around the horizon, an event only visible from Big Bend because of its unique position at the southern border of the U.S.
» March 20, 2008: Standing Tall in
the Galaxy
Arches National Park, Utah (March 28 – April 18, 2008)
Look at any recent image from Mars spacecraft, either in orbit or roving over its surface, and you will be struck by the similarities with the desert southwest. The first images sent back by the Spirit rover looked like a dry red lakebed one might find in southern Utah. Orbital images from Mars Reconnaissance Orbiter appear to show canyons, mesas, and buttes one might see around Moab. My purpose in visiting Arches National Park and the red rock country around it is to learn about the geological forces that produce the many recognizable landmarks of the area. In what way are these forces similar to, and different from, what one will encounter on Mars? These questions start with the very simple: “What makes the red rock country red, and is this the same as what makes the red planet red?” and lead to complicated questions such as, “What are the forces that make hoodoos and buttes and will the lower surface gravity on Mars make these taller, or will the complete lack of rain cause there to be far less dramatic erosion of the landforms?” In short, is there the Martian equivalent of Arches and what would it look like?
» April 11, 2008: Red Rock Planet
Milky Way over Yosemite
The light of the Milky Way shines down on campers in Yosemite Valley in this mosaic of the dark night skies within the California park. Credit: Dan Duriscoe and Chad Moore, National Park Service |
Yosemite National Park, California (May 4 - 11, 2008)
During 2003 Yosemite National Park was the fourth most visited park in the nation. Because of its popularity and its proximity to San Francisco and Los Angeles it is one of the primary places where urban residents are able to see the Milky Way galaxy. Yosemite’s clear night skies therefore join El Capitan and Half Dome as one of its landmark attractions. During the month of May, when visitors descend upon the park at the start of the summer tourist season, the Milky Way rises to the east near midnight and can be seen arching over the canyon for the rest of the night. From a cultural perspective, the Milky Way has a prominent place in many Native American myths and stories. The Chumash of southern California have a very detailed story involving the path a young bride’s and groom’s souls take on the way to the house of the dead. The story’s events along this path have been shown to closely match observable features along the band of the Milky Way.
» May 10, 2008: Hiking the Paths of the Dead
Bryce Canyon National Park, Utah (June 8 - 28, 2008)
Amateur astronomers flock to the national parks as they are one of the last truly dark sky sights left for average Americans to visit. The National Park Service is aware of this fact and has formed the Night Sky Team, headed by Chad Moore at Bryce Canyon National Park in order to quantify and monitor the amount of light pollution above our parks. These observations have shown that Bryce is one of the darkest national parks, yet it is beginning to experience pollution from the nearby Interstate 15 corridor to the west. These are issues affecting many parks, and many more communities around the country. How the National Park Service educates the public on this issue, and how the public responds, are of enormous importance for how this issue is addressed in towns and cities elsewhere in the country. For the moment, because of Bryce’s dark skies, it is one of the premier destinations for the amateur astronomical community. In 2008, Bryce will play host to the 8th annual Bryce Canyon Astronomy Festival (June 25-28).
» June 22, 2008: Starry Sky National Park
Glacier National Park, Montana (July 20 - August 13, 2008)
I will be returning to Glacier National Park to give public talks, telescope viewings and possibly even an astrophotography demonstration. My final stop on my year in the parks will be as a scientist Artist-In-Residence.
» August 3, 2008: Glaciers and the Cosmos
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