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Issue Date: July 8, 2007
Where we're headed
Mars. Rogue asteroids. It's exciting stuff. And this time around, it's not just NASA. Here are four trips to keep your eye on.
By Neil DeGrasse Tyson
Phoenix will go to Mars, with hopes of finding clues about possibilities of life on the planet.
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With dozens of missions now in the works, there has never been a more fascinating time for space exploration. The missions are intended to help us better understand our universe, whether we are investigating life on Mars or searching for solar systems beyond ours. They even seek to avert mass destruction on Earth that's due to an asteroid possibly headed our way. Some people find these to be expensive efforts that amount to scarcely anything of tangible value. But judging from the missions described here, I contend that, with each one, we'll gain a greater understanding of our world, the worlds unnumbered around us and our relationship to them.
1 Phoenix (August 2007) This mission will be launched next month, landing on Mars sometime in 2008. Planetary scientists are looking for possibilities of life on this planet and will use a robotic arm to dig down to a Martian ice layer to see if the arctic plains of Mars could have been -- or still could be -- suited to sustain life. We've always suspected that regions of Mars have frozen water near the surface and that water might, because of periodic changes in climate, melt enough to support life. The robotic arm of Phoenix is long enough to dig deeper than any previous Mars mission. How deep it digs will depend upon how close to the surface it hits a rock-hard ice layer -- maybe 2 inches, maybe 2 feet. Our anticipation is high because every aquifer on Earth supports some kind of life.
Ultimately, why should we care? Well, outside of our endless curiosity about life on other planets, there is our own survival to consider. We may learn that other living things out there -- microorganisms, plants or even what we might call animals -- have found ways to survive various diseases and circumstances that have challenged us here on Earth, possibly giving us greater insight on how to protect ourselves.
2. Selene(July 2007) and Chandrayaan-1 (September 2007) These missions are compelling because they demonstrate the global commitment to understanding outer space. Japan's Selene will orbit and map the moon, setting the stage for future lunar exploration. Chandrayaan-1 is an Indian Space Research Organization (ISRO) mission that will orbit and map the moon's surface over a two-year period, also intended to lead the way to future Indian missions. Will we see more missions conducted by nations not usually associated with space exploration? You'll recall that competition between the United States and the Soviet Union in the 1960s is what ignited the space race. Perhaps one day, nations will pool resources for expensive or complex missions, with the common goal of achieving a better understanding of our place in the cosmos.
3 Dawn (July 2007) This NASA mission will visit two of the largest asteroids in the solar system -- Vesta and Ceres -- studying their crowded environment within the asteroid belt and their composition. It is the first time ever that a spacecraft will orbit two different solar system bodies after launch. There is so much about asteroids that we don't know. Are they massive clumps of solid rock? Are they orbiting piles of rubble, held together by gravity? Today, planetary scientists are pinpointing the days that asteroids may get too close to Earth's surface for comfort. We may shortly need to come up with ways to nudge them off the path of causing damage to our planet. Thanks to missions such as Dawn, we may have a better sense of how to do that when the time comes.
4 Kepler (sometime in 2008) Kepler will be the first NASA mission of its kind, designed to discover planets that are the size of Earth orbiting distant stars. Kepler will need to monitor thousands of stars at once to ensure the best chances of catching a planet within its sights. Think about the possibilities -- that Earth and its solar system may be one of dozens, or hundreds, or thousands, or millions of others. So far, planet hunters have discovered nearly 250 planets beyond our solar system, but almost all of them are giant masses of gas, like Jupiter. Kepler's mission is to find terrestrial planets that may be habitable, like Earth.
Neil deGrasse Tyson, an astrophysicist, is the host of the "NOVA scienceNOW" TV series, airing every Tuesday in Julyat 8 p.m. ET on PBS (check local listings). He also is director of the Hayden Planetarium at the American Museum of Natural History in New York and, most recently, author of the book "Death by Black Hole: And Other Cosmic Quandaries" (W.W. Norton).
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