| 释义 |
periapsis Astr.|pɛrɪˈæpsɪs|
[f. peri- + apsis, after perigee, perihelion, etc.]
That point in the path of a natural or artificial satellite at which it is closest to a primary.
1964J. L. Nayler Dict. Astronautics 194 Periastron (periapsis), the nearest point on the orbit of a stellar satellite to the star, or in a binary star the point at which the companion is nearest to the primary. 1971Nature 26 Nov. 168/3 The manoeuvre, which changed the orbit of the spacecraft so that periapsis (closest approach to Mars) is now 868 miles. 1972Daily Colonist (Victoria, B.C.) 25 Feb. 5/2 Pioneer will be close to Jupiter for about four days (100 hours) and will see the planet in full sunlight 50 hours before periapsis, or the closest point of the fly-by. 1976Sci. Amer. June 59/1 Those commands will..place the spacecraft in an elliptical orbit around Mars that will vary in altitude from 33,000 kilometers at apoapsis down to 1,500 kilometers at periapsis. |