[ad_1]
A new study provides clues indicating that an exoplanet – a planet located outside the solar system that is 500 light-years away and very much like Earth – is orbiting around the world. A star, reported SciTechDaily.com.
Kepler-186f is the first exoplanet the size of a planet identified as orbiting a star in the habitable zone. This means that it is the appropriate distance from its host star so that the liquid water is concentrated on the surface.
The Georgia Tech study used simulations to analyze and identify the dynamics of the spin axis of the exoplanet. These dynamics determine how much a planet tilts on its axis and how this angle of inclination evolves over time. The axial inclination contributes to the seasons and the climate as it affects how sunlight hits the surface of the planet.
The researchers suggest that the axial tilt of Kepler-186f is very stable, just like the Earth. . The Georgia Tech team thinks it's the same for Kepler-62f, a planet the size of a planet that revolves around a star about 1,200 light-years away. we.
What is the importance of axial inclination for climate? The great variability of the axial tilt could be one of the main reasons that Mars went from an aquatic landscape billions of years ago to the barren desert of today.
"Mars is in the habitable zone of our solar system, but its axial tilt is very unstable, ranging from 0 to 60 degrees," said Gongjie Li, assistant professor of Georgia Tech, who led the study. with Yutong Shan, a graduate student at the Harvard-Smithsonian Astrophysics Center in Cambridge, Massachusetts. "This instability probably contributed to the disintegration For comparison, the Earth's axial inclination oscillates more moderately – between 22 , 1 and 24.5 degrees, going from one extreme to the other every 10 000 years or so, reports SciTechDaily.com.
The angle of orientation of the l & # 39; orbit of a planet around its host star can be brought to oscill er by gravitational interaction with other planets in the same system. If the orbit oscillated at the same speed as the precession of the axis of rotation of the planet (similar to the circular motion presented by the axis of rotation of a vertex or d & # 39; a gyroscope), the axis of rotation would also flicker, sometimes dramatically. 19659003] Mars and Earth strongly interact with each other, as well as with Mercury and Venus. As a result, alone, their spin axes precede with the same speed as the orbital oscillation, which can cause significant variations in their axial inclination. Fortunately, the Moon keeps Earth's variations under control. The Moon increases the rate of precession of the axis of rotation of our planet and differentiates it from the rate of orbital oscillation. Mars, on the other hand, does not have a satellite large enough to stabilize its axial tilt.
"It seems that the two exoplanets are very different from Mars and Earth because they have a weaker connection with their twin planets," said Li, a faculty member at the School. of physics. "We do not know if they own moons, but our calculations show that even without satellites, the Kepler-186f and 62f spin axes would have remained constant over tens of millions of years."
Kepler-186f is less than 10% larger in radius than the Earth, but its mass, composition and density remain a mystery. It orbits around its star host every 130 days. According to NASA, the brightness of this star at high noon, standing on 186f, would look as bright as the sun just before sunset here on Earth. Kepler-186f is located in the constellation Cygnus as part of a star system of five planets
Kepler-62f was the Earth's most similar exoplanet until scientists noticed 186f in 2014. It is about 40% bigger than our planet. a terrestrial or oceanic world. It's in the constellation Lyra and it's the farthest planet among five exoplanets orbiting a single star, reports SciTechDaily.com
That's not to say that the # 39, exoplanet has water, not to mention life. "Our studies are among the first to study the climate stability of exoplanets and add to the growing understanding of these potentially habitable neighbor worlds," said Li.
"I do not think we understand enough about the origin of life to exclude the possibility of its presence on planets with irregular seasons, "added Shan of the CfA." Even on Earth, life is remarkably diverse and has shown incredible resilience in extraordinarily hostile environments. "[19659003] "But a climate-stable planet could be a more comfortable place to start."
Source link
