...continued scientific discoveries and bold human exploration that greatly increase human knowledge, understanding and cooperation (through sharing of information and scientific data).
For example, as early as the 19th century, telescope observations led some astronomers to speculate that Mars might harbor life. Subsequent robotic missions to mars during the 1960s and 1970s showed that the surface of Mars is currently inhospitable. However, more recent missions have transformed our understanding of Mars. New data indicate that liquid water likely flowed across the surface of Mars in the distant past and may still exist in large reservoirs deep underground. This raises the prospect that simple forms of life may have been developed early in Mars’ history and may persist beneath the surface of Mars to this day.
In the U.S., NASA is aggressively pursuing the search for water and life on Mars using robotic explorers. The MER Spirit and Opportunity rovers that landed on Mars in January 2004 are the latest in a series of research missions planned to explore Mars through 2010. By the end of this decade, three rovers, a lander, and two orbiters will have visited the planet. NASA will augment this program and prepare for the next decade of Mars research missions by investing in key capabilities to enable advanced robotic missions, such as returning geological samples from Mars or drilling under the surface of Mars. This suite of technologies will enable NASA to rapidly respond to discoveries this decade and pursue the search for water and life at Mars wherever it may lead next decade.
In addition, we know that our solar system is composed of nine planets, including Earth, that circle a central star—the Sun. Astronomers and philosophers have speculated for millennia about whether other stars harbor worlds like Earth and whether these worlds are inhabited. However, it is only in the last decade that telescopes have become powerful enough to detect whether planets of any type circle other stars. In 1995, astronomers discovered the first solar system besides our own. Since then, astronomers have found over 100 planets orbiting other stars—and the number continues to climb with new discoveries.
All of the extrasolar planets discovered to date are either very large planets or planets that circle very close to their parent stars. Some extrasolar planets are many times larger than the largest planet in our solar system, Jupiter, and orbit even closer to their parent star than the closest planet to our Sun, Mercury. Because of the obscuring effects of the earth’s atmosphere and very challenging optical requirements, the detection and characterization of small planets with very normal orbits like Earth is extremely challenging using ground-based telescopes or relatively inaccurate interferometric techniques.
Mr.
Robert
Lewis
Sackheim
Assistant Director & Chief Engineer for Propulsion
NASA, Marshall Space Flight Center, Huntsville, AL
Professional Category:
Engineering
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