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The New Worlds Mission is a proposed project comprising a large occulter in space designed to block the light of nearby stars in order to observe their orbiting exoplanets. The observations could be taken with an existing space telescope, possibly the James Webb Space Telescope when it launches, or a dedicated visible light optical telescope optimally designed for the task of finding exoplanets. A preliminary research project was funded from 2005〔 through 2008 by NASA Institute for Advanced Concepts (NIAC) and headed by Webster Cash of the University of Colorado at Boulder in conjunction with Ball Aerospace & Technologies Corp., Northrop Grumman, Southwest Research Institute and others. Since 2010 the project has been looking for additional financing from NASA and other sources in the amount of roughly US$3 billion including its own 4-meter telescope,〔(The New Worlds Observer ). (PDF) Dr. Webster Cash. University of Colorado, Boulder 2010.〕 or $750 million for one starshade to be used with the James Webb Space Telescope.〔(New Worlds Technology Development for the New Worlds Observer ), (PDF) Dr. Webster Cash. University of Colorado, Boulder 2011.〕 If financed and launched, it would last 5 years. ==Purpose== Currently, the direct detection of extrasolar planets (or exoplanets) is extremely difficult. This is primarily due to: *Exoplanets appear extremely close to their host stars when observed at astronomical distances. Even the closest of stars are several light years away. This means that while looking for exoplanets, one would typically be observing very small angles from the star, on the order of several tens of milli-arcseconds. Angles this small are impossible to resolve from the ground due to astronomical seeing. *Exoplanets are extremely dim compared to their host stars. Typically, the star will be approximately a billion times brighter than the orbiting planet. This makes it near-impossible to see planets against the star's glare. The difficulty of observing such a dim planet so close to a bright star is the obstacle that has prevented astronomers from directly photographing exoplanets. To date, only a handful of exoplanets have been photographed. The first exoplanet to be photographed, 2M1207b, is in orbit around a star called 2M1207. Astronomers were only able to photograph this planet because it is a very unusual planet that is very far from its host star, approximately 55 astronomical units (about twice the distance of Neptune). Furthermore, the planet is orbiting a very dim star, known as a brown dwarf. To overcome the difficulty of distinguishing more Earth-like planets in the vicinity of a bright star, the New Worlds Mission would block the star's light with an occulter. The occulter would block all of the starlight from reaching the observer, while allowing the planet's light to pass undisturbed. The starshade would be tens of meters across and probably made out of Kapton, a lightweight material similar to Mylar.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「New Worlds Mission」の詳細全文を読む スポンサード リンク
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