| 释义 |
perilune Astr.|pɛrɪˈluːn|
[f. peri- + L. lūna moon; cf. perigee, perihelion, etc.]
That point at which a spacecraft in lunar orbit is closest to the moon's centre: applied esp. if the spacecraft was launched from the moon.
1960Aeroplane XCIX. 638/2 Lunar gravity should draw the probe into an orbit which has a period of about 10 hr., an apolune (farthest distance from the Moon) of approximately 3,000 miles and a perilune (closest distance) of 1,500 miles. 1968Sci. Jrnl. Oct. 5/2 The orbital velocity at perilune—altitude 100 km, 2°N latitude—was about 7200 km/hour relative to the Moon. 1969Nature 12 July 129/2 Choosing the major axis of the orbit to pass through the mascon..is equally effective in nullifying the orbital instability represented by cumulatively increasing displacements of perilune and apolune. |