The nearly circular orbit with which eight planets in our solar system revolve has certainly helped them in their quest for survival.

太阳系中八颗行星围绕的近圆形轨道无疑帮助了它们的生存之路。

That represents Earth's axial tilt, which astronomers call its obliquity, relative to the plane of its nearly circular orbit around the sun.

这代表地球相对于其围绕太阳的近圆形轨道平面的轴倾斜，天文学家称之为倾斜角。