Posted on Mar 02, 2009 05:02:27 PM | Kepler | 2 Comments
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The Kepler spacecraft precisely measures the light variations from thousands of distant stars, looking for a moment where the light will change. This light change could signify a planet.
Kepler has a telescope that will focus on the stars that are as large as our Sun. These are the stars that we think may have planets orbiting them. If these stars do have a planet orbiting them then there should be a time where the planet is blocking our solar system's view of the star. This is known as a transit.
Three or more transits of a given star all with a consistent period, brightness change and duration provide a rigorous method of detection and confirmation. Orbital period can be determined from the time between transits. Orbital size can be determined from the mass of the star and the length of time between transits, and temperature from the planet's orbit.
The results from this data can be used to calculate the fraction of stars that have planets, as well as the different planetary sizes and orbits for many different types of stars. These results are especially exciting because they will tell us how often planets occur in the habitable zone of other stars.
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On Jun 04, 2009 02:02:46 PM
guest
wrote:
Nice article!
- 1 On May 14, 2009 08:27:26 PM Charlie wrote:
It's not really correct to say "If these stars do have a planet orbiting them then there *should* be a time...". For each star and planet, there is a relatively small chance that the planet will transit the star. For example, for a distant observer to see the Earth pass in front of the Sun, he/she must be located in a narrow band, less than 1/4 deg above or below the Earth's orbital plane. This covers only about 6% of the sky. This is part of the challenge of Kepler, and the best reason to survey so many stars.
This mission looks at stars that are medium-far away. This gives a statistical estimate of the likelihood that any given star will have planets like ours. With this vital information, we can turn our attention to stars that are much closer to us, and with greater confidence, design a mission like TPF (tpf.jpl.nasa.gov) that could see their light directly, measure atmospheric spectra, and hopefully find evidence of photosynthesis and other biological processes. - 1 On May 14, 2009 08:27:26 PM Charlie wrote:
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