Journey to discover the Kepler spacecraft's

The $ 600 million Kepler spacecraft launched in space in March 2009, designed for the hunt for Earth-like planets outside the solar system.

How does the Kepler spacecraft find "Second Earth"?

Delta II missiles carrying the Kepler space probe from the US Aerospace Agency (NASA) leave the launch pad on March 6, 2009 from Canaveral air base in Florida, USA.(Photo: NASA)

Kepler was NASA's first space-based astronomical vessel, designed for the hunt for Earth-like planets over a three-and-a-half-year period, worth $ 600 million.

Scientists hypothesize that, in addition to the solar system, in the universe there are countless planet-type planets that orbit around a star like the Earth orbiting the Sun.However, it is difficult to detect these planets.

The Kepler spacecraft is designed to identify Earth-like planets, orbiting in the habitable zone around a star like the Sun.The appropriate area is the ideal distance from the planet to the star, where the temperature is not too hot, nor too cold to exist in liquid water.

The Kepler spacecraft has an extremely sensitive photosensitive sensor.To detect a planet the size of the Earth, the photometer must be able to sense light changes at 0.01%.This is like detecting car headlights dimmed in the blink of an eye, when a fly flies over.(Graphics: NASA)

The field of view of the Kepler spacecraft (square beam). (Graphics: NASA)
The area Kepler observed had about 150,000 stars like the Sun.It focuses on finding and measuring the amount of light emitted by stars in the constellation Lyra and Cygnus.

Kepler sought signs of a star's dip (dip) when a planet flew over it. Then, transmit data to NASA's Ames Research Center at Mountain View (California).
The computer here will redraw the light graphs of those stars, based on the data Kepler received.If the signs of this light drop show up continuously on the graph, it means that Kepler has discovered a star with planets flying around.(Photo: NASA)

Operation diagram of the Kepler spacecraft in space.
The sun supplies energy to the Kepler spacecraft through solar panels. Because Kepler's photosensitive sensor is very sensitive, care should be taken not to point it towards the Sun.
Once Kepler discovers planets like Earth, astronomers will redirect the telescope located on Earth, tracking the stars Kepler points out to learn more.

In total, Kepler discovered 4,661 planet candidates, of which 1,028 were confirmed by scientists.
Kepler-22b was announced in December 2011, the remaining three planets announced on April 18, 2013.All can survive life, but people have not yet determined their structure and atmosphere.(Graphics: NASA)

However, only 12 of them, nearly twice the size of the Earth, orbit around their mother stars at the right distance.
After years of searching, NASA announced last week that it had found the "Second Earth" Kepler-452b, about 1,400 light-years away, in the constellation Cygnus.
"Kepler-452b is a small step in the search for the answer, are we the only planet with life in the universe," said John Grunsfeld, NASA expert.

Journey to discover Kepler-452b.(Video: NASA)