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Space Topics: Planetary AnalogsStars Above, Earth BelowAstronomy and Space Exploration in America's National Parks
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The Continental Divide Research Learning Center at Rocky Mountain National Park
Newly restored wood cabins that once housed city dwellers looking to ride horses and sing campfire songs now house scientists (the nerd herd) studying virtually every aspect of Rocky Mountain National Park. Credit: Tyler Nordgren |
The sky over Longs Peak, Rocky Mountain National Park Longs Peak (on the left) is the tallest mountain in Rocky Mountain National Park at 4,345 meters (14,255 feet). It and the light of our galaxy is reflected in the waters of Bear Lake. Credit: Tyler Nordgren |
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 |
Today it is the Continental Divide Research Learning Center, a wonderfully restored collection of log ranch houses and wood cabins looking much as it did in its 1940s heyday. While most of the dude ranches are now gone, the proliferation of hotels, motels, and resorts in every mountain town with an interstate highway attests to the power the mountains still have for us as a place to get away from it all. Here is where we try to experience the untamed wilderness, the way the world is supposed to be.
Part of my project is to identify those places that you can go and take the family to see examples of our world as a planet and be able to connect them to places in our solar system that today’s spacecraft and planetary scientists are revealing. Geysers at Yellowstone? No problem! Stand there on the boardwalk with the throngs of other vacationers and you are seeing processes at work similar to those producing geysers of gargantuan proportions on Saturn’s moon Enceladus.
The Rocky Mountains in Rocky Mountain National Park are a different matter,
however. While the geological processes that shape mountains on Earth can be
found on other planets and moons in our solar system (volcanoes on Venus, Mars and Io;
liquid and wind erosion on Mars and probably Titan;
tectonics on virtually every solid body in the solar system) on Earth they
all come together in a way to make Earth’s mountain ranges unique. Look
at a topographic map of the Earth, or even just North America for that matter,
and one of the obvious features that sticks out is that our mountains are not
loners but rather tend to be laid out in great ragged ribbons. On Earth, tectonism
(the rising, stretching, folding, shrinking, and buckling of a planet’s
crust that are the primary means by which mountains are formed) is found in
the form of plate tectonics.
Our planet’s crust is broken up into about a dozen individual plates
that move around, driven by the forces of heat welling up from inside the planet.
It is at the boundaries of these plates where titanic sections of the planet’s
crust move over, under, or up against one another. The great mountain ranges
form along the edges of these continental plates and where lower density continental
crust and higher density oceanic crusts meet (the Sierra Nevada in the west
and the Appalachians in the east, for example). Over time the location of these
boundaries change as material is added on to the edges of the plates and crustal
material buckles and brakes. The Colorado Plateau in the western US with the
Rocky Mountains at its eastern edge is a record of the history of these interactions.
Topographic map of north and central America
Composite satellite topographic map of North and Central America. Colors denote elevation. Notice the band of the Rockies extending from Northern Canada all the way through Central America on the west and the Appalachians running the Atlantic coast on the east. Credit: NASA |
Earth is alone in having these plates. There just isn’t anything like them in elsewhere in the solar system. Venus, similar in size to Earth, appears to have a solid surface through which its internal heat struggles to escape. Great blobs of molten material well up to deform the surface creating enormous circular chains of fractures called coronae. Two great volcanoes (Alpha and Beta Regio) on opposite sides of the planet produce a network of planetary stretch marks looking something like mountain chains bordering deep rifts. But on the dry, blazing inferno of Venus’ surface, no future explorer is going to mistake these rift valleys for the Rocky Mountains’ towering cliffs of granite formed deep in the Earth and cracked and carved by the freezing cycle of water.
Flattop mountain
The faces of the Rocky Mountains have been weathered extensively by the freezing and thawing of water, an action not found on any other planet or moon in the solar system. Credit: Tyler Nordgren |
Through a small telescope the Moon is revealed to have mountain chains. The lunar Apennines are a favorite of mine. But like on Venus, these mountain chains are also laid out in great circles. These mountains, however, are the rough walls of ancient impact basins. In the airless void of space, no melting snow waters have weathered these mountains in four billion years, so they remain soft and rounded as gravity slowly relaxes them.
Mountains on the Moon
These lunar mountain ranges along the terminator are the boundary of an enormous impact basin. Credit: Tyler Nordgren |
On Mars the most obvious tectonic features are the enormous mass of the Tharsis Bulge (with its giant volcanoes) and the attendant cracks in its surface that radiate outwards (Valles Marinaris being the spectacular chief example). But even on Mars we heed Muir’s call, and so while I stop and admire the stars from the summit of the Rockies I think about the first extraterrestrial mountain climber still rolling across the tops of the Columbia Hills on Mars’ Gusev Crater.
Star from the Summit
Star trails from the 3,700-meter (12,000-foot) summit of the Trail Ridge Road through RMNP. From this point one can look both north and south along the chain of the Rocky Mountains. Credit: Tyler Nordgren |
Spirit panorama: "Everest," sols 620-622
Spirit crawled to the true summit of Husband Hill to capture this breathtaking view of the interior of Gusev crater from sols 620 to 622 (October 1 to 3, 2005). For the full-resolution image, visit the Pancam website. Credit: NASA / JPL / Cornell |
I’m in the middle of giving a number of public talks on the work of the National Park Service Night Sky Team, and next week I will be meeting with park personnel to talk more about light pollution. I have received tremendously positive responses to my presentations so far, including requests for my talks to be made available online. I will take care of that within the next couple of weeks. In the meantime, I am here for a little more than a week before heading off to Grand Tetons National Park for the total lunar eclipse on August 28.
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