单词	periapsis
释义	periapsis /ˌpɛrɪˈapsɪs / noun (plural periapses /ˌpɛrɪˈapsiːz/) Astronomy The point in the path of an orbiting body at which it is nearest to the body that it orbits.For objects orbiting Earth, periapsis and apoapsis are known as perigee and apogee; for objects orbiting the Sun, these locations are known as perihelion and aphelion.... At periapsis [closest approach to Saturn] it's about 40 kilometers per second [90,000 miles per hour].
随便看	row barge rowboat row boss rowcast row crop row culture row de dow rowdily rowdiness row dog rowdy rowdy-dow rowdy dowdy rowdying rowdyish rowdyism roweite rowel rowen Rowe, Nicholas rower rower-back rowet rowett row-galley

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