寻找新地球

Kepler-22b is the first planet discovered inside the habitable zone of a Sun-like star. This artist’s conception from 2011, shows the first planet that NASA’s Kepler mission has confirmed to orbit the region around a star where liquid water, a requirement for life on Earth, could exist. This exoplanet is 2.4 times the size of Earth, making it the smallest yet found to orbit in the middle of the habitable zone of a star like our Sun.

At the time scientists did not know if the planet has a predominantly rocky, gaseous or liquid composition. It’s possible that the world would have clouds in its atmosphere, as depicted here in the artist’s interpretation.

Image Credit: NASA/Ames/JPL-Caltech

开普勒-22b是在类太阳恒星的宜居带内发现的第一颗行星。这是2011年的艺术家构想，显示了NASA开普勒任务确认的第一颗行星，该行星围绕一颗恒星运行，那里可能存在液态水，而液态水是地球上生命存在的必要条件。这颗系外行星的大小是地球的2.4倍，是迄今为止发现的在像太阳这样的恒星的宜居带中间运行的最小的行星。

当时，科学家们还不知道这颗行星的主要成分是岩石、气体还是液体。这个世界的大气中可能有云，正如艺术家在这里所描述的那样。

图片来源：NASA/Ames/JPL-Caltech