The curvature of the Earth’s horizon (the limb) is clearly visible, as is the faint blue line of the upper atmosphere directly above it (at image top center).
地球地平线的曲线（周边）清晰可见，它的正上方隐约显现出高层大气的蓝线（图片中上部）。
2
The curvature of the Earth's horizon (the limb) is clearly visible, as is the faint blue line of the upper atmosphere directly above it (at image top center).
地球地平线的曲线(周边)清晰可见，它的正上方隐约显现出高层大气的蓝线(图片中上部)。
3
When viewed from northern latitudes, and as shown in the above horizontally compressed image, the Sun will make its lowest arc through the sky along the southern horizon.