Ganymede is the largest natural satellite that exists in the Solar System. It has a diameter greater than Mercury, and its size is three quarters of Mars. If instead of Ganymede orbiting Jupiter around the Sun, it would have been accepted as one more planet.
Magnification (or magnification) Dictionary of astronomy, letter M Magnification or magnification of a telescope is given by the relationship between the Focal distance of the objective and that of the eyepiece. As the objective of a telescope is fixed, to increase or reduce the magnification the eyepiece is changed. Every telescope, usually, is put on sale with a series of eyepieces that allow a wide selection of magnifications.
Selenology Astronomy dictionary, letter S Selenology is a branch of astronomy and consists in the study of the composition and evolution of the Moon as a celestial body and the structures that form its surface. Selenology is synonymous with lunar geology. This is a branch of science that can have a great future if, as expected, advances in astronautics allow for a continuous and direct study of our satellite.
Given that Neptune is one of the coldest planets and away from the Sun, talking about the "spring" may seem exaggerated, but the most recent images obtained using the Hubble space telescope can almost affirm it. Its southern hemisphere is brighter and astronomers think it is a seasonal change.
Angular diameter Astronomy dictionary, letter D It is the apparent diameter of a celestial object, measured in degrees and degree fractions. Let us underline the apparent word, since the Sun and the Moon, for example, seen from Earth have an equal angular diameter of approximately half a degree, while their effective diameter is respectively 1.
Voyager (probe) Dictionary of astronomy, letter V Name of two twin interplanetary automatic probes made by NASA, which between the late 1970s and the course of the 1980s revolutionized our knowledge of the bodies of the outer solar system, sending millions of data and images about the planets and their satellites of the Jupiterian type.