土星的夏天

NASA’s Hubble Space Telescope captured this image of Saturn and its colossal rings on July 4, 2020, during summer in the gas giant’s northern hemisphere. Two of Saturn’s icy moons are also clearly visible: Mimas at right, and Enceladus at bottom.

The light reddish haze over the northern hemisphere seen in this color composite could be due to heating from increased sunlight, which could either change the atmospheric circulation or remove ices from aerosols in the atmosphere. Another theory is that the increased sunlight in the summer months is changing the amounts of photochemical haze produced. Conversely, the just-now-visible south pole has a blue hue, reflecting changes in Saturn’s winter hemisphere.

This image was taken as part of the Outer Planets Atmospheres Legacy (OPAL) project. OPAL is helping scientists understand the atmospheric dynamics and evolution of our solar system’s gas giant planets. In Saturn’s case, astronomers continue tracking shifting weather patterns and storms.

Image credit: NASA, ESA, A. Simon (Goddard Space Flight Center), M.H. Wong (University of California, Berkeley), and the OPAL Team

NASA的哈勃太空望远镜在2020年7月4日拍摄了这张土星及其巨大光环的照片，当时正值这个气态巨行星的北半球夏季。土星的两个冰卫星也清晰可见：土卫一在右边，土卫二在底部。

在这幅彩色合成图中，北半球淡红色薄雾可能是阳光增加引起的加热造成的，这可能会改变大气环流或从大气中的气溶胶中去除冰。另一个理论是，夏季阳光的增加改变了光化学烟雾的产生量。相反，刚刚可见的南极呈蓝色，反映了土星冬季半球的变化。

这张照片是作为外行星大气遗产（OPAL）项目的一部分。OPAL正在帮助科学家了解我们太阳系气态巨行星的大气动力学和演化。就土星而言，天文学家继续追踪不断变化的天气模式和风暴。

影像来源: NASA, ESA, A. Simon (Goddard Space Flight Center), M.H. Wong (University of California, Berkeley), and the OPAL Team