The Kepler spacecraft is an American space
observatory, the
space-based portion of NASA's Kepler Mission to discover Earth-like planets orbiting other stars. The
spacecraft, named in honor of the 17th-century German astronomer Johannes
Kepler, was launched in March 2009with
a planned mission lifetime of at least 3.5 years.
The Kepler mission is "specifically designed to survey a
portion of our region of the Milky Way galaxy to discover dozens of
Earth-size planets in or near the habitable
zone and determine how many of the
billions of stars in our galaxy have such planets." Kepler's only instrument is a photometer that continuously monitors the
brightness of over 145,000 main sequence stars in a fixed field of view.
This data is analyzed to detect periodic fluctuations that
indicate the presence of extrasolar planets that are in the process
of crossing the face of other stars.
Mission Of Spacecraft
Mission Of Spacecraft
The centuries-old quest for other worlds like our Earth has
been rejuvenated by the intense excitement and popular interest surrounding the
discovery of hundreds of planets orbiting other stars. There is now clear
evidence for substantial numbers of three types of exoplanets; gas giants,
hot-super-Earths in short period orbits, and ice giants. The challenge now is
to find terrestrial planets (i.e., those one half to twice the size of the
Earth), especially those in thehabitable zone→ of their stars where liquid
water might exist on the surface of the planet.
The Kepler Mission, NASA Discovery mission #10, is specifically designed to survey our region of the Milky Way galaxy to discover hundreds of Earth-size and smaller planets in or near the habitable zone→ and determine the fraction of the hundreds of billions of stars in our galaxy that might have such planets.
The Kepler Mission, NASA Discovery mission #10, is specifically designed to survey our region of the Milky Way galaxy to discover hundreds of Earth-size and smaller planets in or near the habitable zone→ and determine the fraction of the hundreds of billions of stars in our galaxy that might have such planets.
Instrument
The Kepler instrument is a specially designed 0.95-meter
diameter telescope called a photometer or light meter. It has a very large
field of view for an astronomical telescope — 105 square degrees, which is
comparable to the area of your hand held at arm's length. It needs that large a
field in order to observe the necessary large number of stars. It stares at the
same star field for the entire mission and continuously and simultaneously
monitors the brightnesses of more than 100,000 stars for the life of the
mission—3.5 or more years.
The photometer must be spacebased to obtain the photometric precision needed to reliably see an Earth-like transit and to avoid interruptions caused by day-night cycles, seasonal cycles and atmospheric perturbations, such as, extinction associated with ground-based observing.
Results from the Kepler mission will allow us to place our solar system within the context of planetary systems in the Galaxy.
The photometer must be spacebased to obtain the photometric precision needed to reliably see an Earth-like transit and to avoid interruptions caused by day-night cycles, seasonal cycles and atmospheric perturbations, such as, extinction associated with ground-based observing.
Results from the Kepler mission will allow us to place our solar system within the context of planetary systems in the Galaxy.
Courtesy Wekipedia, NASA
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