作者：Space 2019-08-10 16:55
Astronomers have found a nearby "super-Earth" exoplanet that may be capable of supporting life as we know it.
An international group of astronomers discovered the planet using NASA's Transiting Exoplanet Survey Satellite (TESS) earlier this year in the constellation Hydra, about 31 light-years from Earth, according to a statement by NASA.
(One light-year is the distance light travels in a year, about 6 trillion miles, or 10 trillion kilometers.)
The exoplanet, named GJ 357 d, is believed to be around twice the size of Earth and harbor six times Earth's mass.
这颗称为GJ 357 d的外星球据认为大约有地球两倍大，质量为地球的六倍。
Located in the outer edge of its host star's "habitable zone," scientists believe that this super-Earth could have water on its surface.
"If the planet has a dense atmosphere, which will take future studies to determine, it could trap enough heat to warm the planet and allow liquid water on its surface," Diana Kossakowski, a researcher at the Max Planck Institute for Astronomy in Heidelberg, Germany, and co-author of the recent study, said in the statement.
The potentially habitable planet and two neighboring worlds were found orbiting around a dwarf star, around a third the size and mass of our own sun and 40% cooler.
TESS noticed that the light coming from this small star dims slightly every 3.9 days — a clue that an exoplanet may be transiting its face.
That world is GJ 357 b, a "hot Earth" that orbits 11 times closer to its host star than Mercury does to the sun and likely has a surface temperature of around 490 degrees Fahrenheit (254 degrees Celsius).
这颗星球是GJ 357 b，被称为“热地球”，距离其主恒星的距离比水星与太阳的距离近11倍，表面温度可能约为490华氏度（254摄氏度）。
But GJ 357 b's possibly habitable neighbor planet soon stole the show.
但GJ 357 b旁边可能适宜居住的星球很快就抢占了风头。
Further observations showed that GJ 357 d orbits its star every 55.7 days at a distance of around a fifth of Earth's distance from the sun, and could have Earth-like conditions, according to a statement from Cornell University.
康奈尔大学的一份声明称，进一步的观察显示GJ 357 d围绕恒星的运行周期为55.7天，距离其主恒星的距离约为日地距离的五分之一，条件与地球相似。