Page:Illustrated Astronomy.pdf/57



The ancient Greeks were right when they thought that the Moon phases could be explained through its relative motion around the Earth and that it is much closer than the Sun. The reason why we can see some brightness, even in those parts where the Sun can’t light directly, is because of the sunlight reflection on the Earth’s surface.

DID YOU KNOW THAT…

...we can see more than one face of the Moon?

''In fact, we can see about 59 % of the Moon from Earth thanks to a phenomenon called libration. Libration is an oscillation of the Moon in relation to Earth, and it happens for three reasons: libration in longitude (results from the eccentricity of the lunar orbit); libration in latitude (results from a slight inclination of the rotation axis regarding its orbit with Earth); and diurnal libration, which is a consequence of the Earth’s rotation. So, if we see the Moon at breaking dawn, midday, or twilight, we have different perspectives of it, its position in the sky, and its size.''

DID YOU KNOW THAT…

...as the Earth reflects the Sunlight onto the Moon’s surface, some astronomers have observed the dark side of it using terrestrial telescopes?

How does this work?

''The Sunlight reflects itself on Earth, and gently lights up the dark side of the Moon. Such light has the characteristics, or chemical fingertips of the terrestrial atmosphere tattooed, allowing us to observe the Earth as if it were an exoplanet.'' • • • 57