x 1024 kg and radius RE = 6.371 x 10 m. 3. When the Earth reaches the aphelion of 1.52 x 101l m, its speed is 2.93 x 104 m/s. After a half year, the Earth moves to the perihelion of 1.47 x 101l m. Find: (a) The speed of the Earth at the perihelion. (b) The angular speeds of the Earth at the aphelion and perihelion. atellite