Libration of the Moon.
As the orbit is ecliptic and the axis of rotation is inclined from the perpendicular to the orbital plane, there is an effect known as libration (in longitude and latitude) that we can see from our planet a little more than half of the lunar surface (59%).
The libration in longitude because the Moon rotates uniformly about its axis, while the orbital motion is faster near the perigee Maas and slower near the peak (by Kepler's second law). Therefore, a lunar surface detail, which at perigee and apogee is located right on the meridian of the place, find something to the east of the meridian when the Moon is between the perigee and apogee, and slightly to the west when it is between the apogee and perigee.
This implies that we see over 50% of the area lunar.El period of libration in longitude is equal to the anomalistic month.
The libration in latitude is due to the inclination of the lunar rotation axis perpendicular with respect to the orbital plane. The period of libration in latitude is equal draconítico month.
The night or parallactic libration depends on the place of observation on the surface of the Earth: two observers who are in two different points on the earth's surface at one time see something different regions of the lunar surface.
0 comments:
Post a Comment