The new technology will see on the planets for signs of life, such as oxygen and liquid water
Despite the fact that in the last 15 years have been discovered hundreds of planets orbiting other stars, we still can not answer the perennial question of whether there is life on any of these planets. However, new technology, NASA can make a difference by providing the opportunity to observe not only the planets similar to our size, located in a potentially habitable zone of its star, but also the opportunity to see such signs of life, such as oxygen and liquid water.
Scientists at the Research Center of NASA "Ames" in Moffitt Field, California, to develop new optics space telescope, which is able to not only detect planets similar to Earth, but also to photograph them. To create such pictures called 'direct visualization', the new technology will be used as a technique called phase induction amplitude apodization (PIAA). Apodization Development began in 2003, and during that time managed to demonstrate the correctness of the concept of ideas and technology. The researchers tested the prototype, and the project should be implemented during the upcoming space missions, organized by NASA to obtain images of exoplanets. The mission itself is planned for the 2020s.
"By blocking the glare and diffraction from the star, we can see those planets that without the new technology would be hidden. Thanks to the new product, we first obtain a direct image of exoplanet potentially habitable zone "- says Ruslan Belikov, an astrophysicist at NASA and the technical team leader in the Ames engaged in experimental development coronagraph.
PIAA system uses two specially designed aspherical optical device to change the light in the "vision" of the telescope and make this light "high contrast", suitable for photographic images. Photo from nasa.gov
Today, scientists generally use indirect methods, one of which, for example, is the "transit method" to detect planets outside the solar system. In accordance with measured dimming star when the planet passes between it and the line of sight of the telescope. Watching the stars lighting changes, scientists can determine the size of the planet, its distance from the star and its orbital period. This method is currently used by the mission "Kepler", launched by NASA in 2009; its purpose is to find a potentially habitable zone planets similar in size to Earth.
In the future, however, for the detection of biomarkers of life, such as oxygen and liquid water on planets that resemble Earth, orbiting a star similar to our sun, a different approach will be used in design and concept. PIAA has the ability to "direct visualization," which refers to the actual photograph exoplanets. The difficulties in creating such pictures that the brightness of the star causes diffraction and reflections, lighting orbiting planet. To solve this problem, the telescope is necessary to suppress the diffraction of light stars.
PIAA system uses two aspherical mirrors specially designed to convert light sensors registered a telescope, a new facility is recognized by their high contrast. This new high contrast is able to suppress diffraction and turn the bright light from the stars in the image in a small spot, which effectively blocks the light emitted by the star, which, however, does not affect the perception of the light emitted by the planets. Tools that block the light of the stars, commonly referred to as "coronagraphs"; originally they were designed to lock radiance of the Sun, so that we can see its outer shell of gas or crown. PIAA - is a kind of a particularly powerful type of the coronagraph, set up on the edge of modern knowledge of physics.
Telescope optics has tiny defects, so-called aberration, which causes image blurring in the star. At the present level of development of our civilization is not possible to create an entirely free from aberrations of the optics, but can be adjusted by means of separate mirrors that can rapidly change their shape. "Such mirrors are called deformed. They warn potential distortion optics of the telescope, "- said Belikov. PIAA coronagraph or a whole block of stars shine, but they are able to show the planet earth requested only if the size of the telescope optics is perfect, which never happens.