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Astronomers have found more and more evidence of exoplanets similar to Earth. Many features are really similar to the Earth, with very regular seasonal variations and a stable climate. This is the first time that astronomers have been exploring the climatic stability of exoplanets, and it is useful to understand these neighboring worlds that may be suitable for survival.
Kepler-186f has about 492 lumens In the year, it was the first exoplanet to identify a Size close to the Earth and located in the habitable zone of the parental star. This means that if the planet is at a moderate distance from its parent star, it will allow surface water to exist in the liquid state.
The astronomer Gongjie Li (Li Gongjie?) Of Georgia Tech and others used computer simulation to badyze and confirm the dynamics of the outer axis of the exoplanet, so to determine the axis of rotation of an exoplanet. The size of the hanging and how it evolves over time. The tilt of the axis of rotation affects the angle and the energy distribution of the sun shining on the surface of the planet, which affects the seasonal changes and the climate of the planet .
Their results show that the Kepler-186f rotation axis is as stable as the Earth, so the seasonal variation of Kepler-186f is fairly steady and the climate is stable, then Kepler-62f is also found. The Kepler-62f is an extraterrestrial exoplanet, about 1,200 light-years away from Earth.
Although Mars is in the habitable zone of the Sun, the tilt of the axis of rotation of Mars can range from 0 to 60. A change of inclination as important will cause a dramatic change in the Perhaps the rich water climate of Mars billions of years ago. The state has become the main cause of the desert surface of today, and this instability can also be responsible for the loss of the Martian atmosphere and the evaporation of the waters. of surface. In contrast, the angle of inclination of the Earth's axis of rotation is quite mild, and the time of 22.1 degrees at 24.5 degrees is as long as 10,000 years.
The angle of orientation of a planet orbiting the orbit of a parent is oscillated by the gravitational interaction of other planets in the same planetary system. If the speed of oscillation is the same as the speed of the precession of the planetary axis of rotation, the axis of rotation will also oscillate back and forth, and sometimes the time of rotation. oscillation will be severe. Precession means that the orientation of the axis of rotation in the space will progressively evolve around a fixed axis, such as a gyroscope, the precession of the axis of rotation of the Earth being the source of precession.
The interaction between Mars and Earth is very strong, as well as Mercury and Venus. Therefore, their rotation axis precession and orbital orientation angle rotation speed are the same, which can significantly vary their angle of inclination of the ## EQU1 ## 39, axis of rotation. Fortunately, the presence of the moon accelerates the rate of precession of the earth's axis of rotation, making it different from orbital directional angular oscillation rate, thus stabilizing the Earth's axis of rotation . Mars is not so lucky, its two satellites are not big enough to stabilize its axis of rotation.
Li et al. The results show that Kepler-186f and Kepler-62f are very different from Earth and Mars because they do not interact well with their neighboring planets. It is not known whether they have satellites large enough, but according to their calculations, they show that even without satellites, their axis of rotation remains almost unchanged for tens of millions of years.
Kepler-186 is in the direction of Cygnus and is currently known to have five planets. The Kepler-186f radius is 10% larger than the Earth, but its mbad, chemical composition and density are unknown. The revolution period is about 130 days According to other NASA studies, the Kepler-186 star's brightness at midday at Kepler-186f is about the same as the brightness of sun seen before sunset on Earth.
Kepler-62 is in the direction of Lyra, and the number of known planets is also five, of which Kepler-62f is the outermost planet. The Kepler-62f has a radius of about 40% larger than the Earth, and can be a rocky planet or a world covered by the oceans. In 2014, the discovery of Kepler-186f brought out Kepler-62f from the most similar exoplanet throne.
The two planets are located in the habitat of their parent stars, but that does not mean that there must be water on their surface, let alone that it there is life. Currently, scientists do not know enough about the origin of life, so there is no way to exclude the possibility of life on the exoplanet with irregular seasons, even on Earth , the lifestyle is complicated and varied, showing that life has an astonishing elasticity. Survive in an environment that was not initially thought possible. However, in all cases, a planet with a stable climate is more conducive to life and survival.
Source: http://www.news.gatech.edu/2018/06/28/more-clues-earth-exoplanets-are-indeed-earth, 2018.06.28, KLC
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