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The search begins... Are we alone?
For
centuries, human beings have pondered this question. Medieval scholars
speculated that other worlds must exist and that some would harbor other
forms of life. In our time,
advances in science and technology have brought us to the threshold of
finding an answer to this timeless question. The recent
discovery of numerous planets around stars other than the Sun confirms that
our solar system is not unique. Indeed, these "extrasolar planets"
appear to be common in our galactic neighborhood. The
extrasolar planets we have discovered thus far are giants, like Jupiter and
Saturn. They are unlikely to support life as we know it. But some of these
planetary systems might also contain smaller, terrestrial planets like Mars
and Earth. Over the next
15 years, NASA is embarking on a bold series of missions to find and
characterize new worlds. These will be the most sensitive instruments ever
built, capable of reaching beyond the bounds of our own solar system.
The Keck
Interferometer will combine the light of the world's largest optical
telescopes, extending our vision to new distances. Using a
technique known as interferometry, the Keck will study dust clouds around
stars where planets may be forming. It may also provide the first direct
images of giant planets outside our solar system. The Space
Interferometry Mission will measure the distances and positions of stars with
unprecedented accuracy. SIM's precision will allow us to detect evidence of
planets just slightly larger than Earth. Finally, the
Terrestrial Planet Finder will build upon the legacy of all that have gone
before it. With an imaging power 100 times greater than the Hubble Space
Telescope, Terrestrial Planet Finder will send back the first photographs of
nearby planetary systems.
We will
analyze the atmospheres of these distant worlds, looking for carbon dioxide,
water and ozone. The substantial presence of all three gasses would suggest
that life is present. Such a
discovery would at last provide convincing evidence that we are not alone. We will have
found another Earth. |
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Children's Museum website |