The time of opposition can occur as much as 8.5 days away from the closest approach. The distance at close approach varies between about 54 and about 103 million km due to the planets' elliptical orbits, which causes comparable variation in angular size.
Cosmos often simply means universe. But the word is generally used to suggest an orderly or harmonious universe, as it was originally used by Pythagoras in the 6th century B.C. Thus, a religious mystic may help put us in touch with the cosmos, and so may a physicist.
A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter. The word galaxy is derived from the Greek galaxias (Î³Î±Î»Î±Î¾Î¯Î±Ï), literally milky, a reference to the Milky Way. Galaxies range in size from dwarfs with just a few hundred million (108) stars to giants with one hundred trillion (1014) stars, each orbiting its galaxy's center of mass.