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Galaxies
++ Galaxies are vast systems of stars, gas, dust, and dark matter, + bound together by gravity. There are different types of galaxies, + including spiral galaxies, elliptical galaxies, and irregular + galaxies. Each type has unique characteristics and structures. +
+
Solar Systems
++ A solar system consists of a star and all the objects that are bound + to it by gravity, including planets, moons, asteroids, comets, and + meteoroids. Our solar system, with the Sun at its center, is just + one of many in the universe. There are various types of solar + systems, each with different arrangements and characteristics of + celestial bodies. +
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