On March 6, 2009, Kepler telescope was launched into space to detect Earth analogs, which are planets that have a star to orbit like our sun in the habitable zone. In doing so, Kepler can detect planets that orbit in front of their stars and document its existence. Kepler has a 95-megapixel array of charge-coupled devices, the largest camera currently launched into space. After Kepler’s 3-year mission, astronomers discovered the first Earth-size planet orbiting a star in the habitable zone (NASA, Kepler mission).
Kepler-186f” was discovered within the Kepler-186 system. Nearly 500 light-years from Earth in the constellation Cygnus, Kepler’s system has a total of four planets and an M dwarf star that orbits once every 130-days. In the Milky Way Galaxy, 70% of the stars are dwarfs. "M dwarfs are the most numerous stars," said Quintana. "The first signs of other life in the galaxy may well come from planets orbiting an M dwarf." The four planets that reside on the Kepler system are: Kepler-186b, Kepler-186c, Kepler-186d, and Kepler-186e.
According to researcher Thomas Barclay, "Being in the habitable zone does not mean we know this planet is habitable. The temperature on the planet is strongly dependent on what kind of atmosphere the planet has. Kepler-186f can be thought of as an Earth-cousin rather than an Earth-twin. It has many properties that resemble Earth."
Furthermore, the five
planets discovered around Kepler-186 are all expected to have a solid surface.
The smallest one, Kepler-186b, is only 8% larger than Earth, while the largest
one, Kepler-186d, is almost 40% larger. "The four innermost planets are
probably tidally locked, but Kepler-186f is further out, where the star's tidal
effects are much weaker, so there may not have been enough time for its spin to
slow down that much. Because of the very slow evolution of red dwarf stars, the
age of the Kepler-186 system is poorly constrained, although it is likely to be
greater than a few billion years. There is a roughly 50-50 chance it is
tidally locked. Since it is closer to its star than Earth is to the Sun, it
will probably rotate much more slowly than Earth; its day could be weeks or
months long." - Tidal effects on rotation rate, axial tilt and orbit
Comments
Post a Comment