libration

• اسم يشير إلى تذبذب أو تمايل حقيقي أو ظاهري لجسم فلكي كالقمر أو تابع، يُرى من جسم سماوي أكبر.

A noun referring to a real or apparent slow oscillation of a moon or satellite, as observed from a larger celestial body.

1. Astronomical oscillationC1formalscientific

   A real or apparent slow oscillation of a moon or satellite, such as the Moon, as seen from its primary planet.

   تراوح فلكي

   • The Moon's libration allows us to see slightly more than half of its surface from Earth.
   • Libration in longitude is caused by the Moon's elliptical orbit.
   • Astronomers study lunar libration to map the far side of the Moon.