NASA Craft To Leave Vesta Heads For Dwarf Planet Ceres 116
DevotedSkeptic writes "NASA's Dawn probe is gearing up to depart the giant asteroid Vesta next week and begin the long trek to the dwarf planet Ceres, the largest object in the asteroid belt. The Dawn spacecraft is slated to leave Vesta on the night of Sept. 4 (early morning Sept. 5 EDT), ending a 14-month stay at the 330-mile-wide (530 kilometers) body. The journey to Ceres should take roughly 2.5 years, with Dawn reaching the dwarf planet in early 2015, researchers said. 'Thrust is engaged, and we are now climbing away from Vesta atop a blue-green pillar of xenon ions,' Dawn chief engineer and mission director Marc Rayman, of NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. 'We are feeling somewhat wistful about concluding a fantastically productive and exciting exploration of Vesta, but now have our sights set on dwarf planet Ceres.'"
Vesta flyby video (Score:5, Interesting)
Here's a cool video [youtube.com] generated from pictures taken by the probe as it orbited the asteroid.
Asteroid Vesta and dwarf planet Ceres (Score:3, Interesting)
According to NASA - http://www.nasa.gov/mission_pages/dawn/ceresvesta/index.html [nasa.gov] - Asteroid Vesta mainly consists of rock while dwarf planet Ceres is mainly ice
What is interesting is the picture of the meteorite that NASA claims is from asteroid Vesta. That rock is made up of almost entirely mineral Pyroxene - http://en.wikipedia.org/wiki/Pyroxene [wikipedia.org] - which is common in lava flow
Hmm ...
How can an asteroid of only 330 mile wide have volcano that spewed out lava ?
Re:Good luck Dawn (Score:4, Interesting)
Space is cold, and dry. It can be pretty hard to find water out there, and gas stations are far between.
Planetary Resources [planetaryresources.com] is a company in Seattle set up to mine asteroids. The big deal at first is asteroid-borne water, which comprises up to 30% of some asteroids. They are going after asteroids that pass near the Earth at first.
The big deal is what potentials this opens up for expoloration of our solar system and the stars. With energy water can be converted into LH2/LO2 fuel. The problem is that lifting up the fuel from our deep gravity well makes this prohibitively expensive.
Ceres may have 200 million cubic kilometers [wikipedia.org] of water ice, almost all of it relatively pure and on the surface, 100km thick. That's more water than all of the fresh water on Earth. Ceres has a surface gravity of 0.03 g, so getting the ice or fuel away from there is no big deal. There may be other volatiles there as well - Xenon would be a great find. We've found water on the moon and Mars, but getting the water away is nearly impossible because the gravity on these bodies is just too high. Small asteroids aren't plentiful enough for a huge explosion of exploration and manned habitation in space.
Abundant water and energy are the two essential keys to human and robotic exploration of the solar system. If we can somehow with robots bring energy and equipment to this ball of water we can bring back enough fuel to scoop much larger payloads out of much cheaper near Earth Orbits and move them anywhere from there. That enables larger habitations with centrifugal simulated gravity, water ice mass shielding from radiation, million-kilo LH2/LO2 rockets that start in microgravity and so don't have to spend 90% of their fuel lifting up out of our gravity well.
Ice makes a great construction material too, so if we found a way to put humans on Ceres they need not worry too much about radiation or building materials. It's also a great thermal insulator, and we've learned how to carve habitats out of ice in Antarctica.
In short if that water is really there it is the key to humans establishing a permanent occupation of space, and maybe the fuel we'll use to send the first probes to nearby stars. We'll know in about 30 months.
Re:Good luck Dawn (Score:4, Interesting)
This is an interesting point. A sufficiently deep subsea human habitat that was self-sufficient might be enough to preserve mankind against even a planet-killer asteroid, if it survived the initial shock wave. Certainly many aquatic species survived the last dinosaur killer, including sharks. If you put it at the equator it should be safe from ice ages. Geothermal energy would be persistent enough, even if the uranium from seawater thing didn't work out. It would have to be a subsea city with pop > 100k though to provide a persistent level of science and culture.
There's probably a good trilogy of books in this one if you want to develop it.
Not proof against nuclear war though. If I know anything about my fellow men, they're griefers and when the shit hits the fan a subsea survival habitat is going to have several torpedos with its name on them, some of them nuclear.
Re:Good luck Dawn (Score:4, Interesting)
Colonization of Ceres requires that the humans live in a huge centrifuge because humans don't bear up well under such a tiny gravity in the long term and centripetal force is a fair substitute. Construction of such a centrifuge on Ceres would require considerable resources we don't have because Ceres has both significant gravity and spins on an axis. Ultimately a human habitat on orbit of Ceres seems more likely to me than one burrowed into the ice for this reason, as the centrifuge is simpler on orbit. In fact, the operation of human habitat polar centrifuges would alter the poles of Ceres and be self-defeating. But given such a habitat on orbit, short-term surface ventures and shelter from solar storms are trivial with a surface gravity of 0.03 g and unlimited available fuel from refinery operations. A space elevator on Ceres though, that would make better sense than anywhere else in the solar system.
No, I'm excited about Ceres only as a source of water for LH2/LO2 fuel, O2 for breathables, water for drinking, minerals for refining and fabrication - not as habitat. It may be 50 years or more before we put people there and that will be out of scope for me.