Earth's solar system has only one sun, but if the word "sun" is taken to mean "any star with planets in orbit," the Milky Way might have as many as 400 billion suns. If the observed ratio of approximately one planet per ... More »

The exact number of stars in the universe is not known, and the total figure might be unknowable from the Earth's position in space. The universe almost certainly contains no fewer than 10^24, or 1 septillion, stars, and... More »

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According to NASA, more than 1,700 planets have been confirmed outside of our own solar system. However, the number of planets in the universe could essentially be infinite because scientists have yet to find the so call... More »

A nucleus of an atom can be compared to the sun of a solar system because the nucleus, like the sun, is the largest part of an atom and its electrons orbit around it, much like planets in a solar system. Atoms can also g... More »

The planets of the solar system revolve around the Sun due to the force of its gravitational pull. The elliptical orbit of the planets is a result of the Sun's gravity, which acts to pull the planets closer, balanced by ... More »

The planets of the solar system maintain their orbits around the Sun due to its gravitational pull. Planetary orbits are determined by two forces: the Sun's gravity pulling them inwards and the inertia of their movement,... More »

The Earth's orbit around the sun is controlled by two things. The first is the gravity of the sun, and the second is the way the earth moves sideways in space. More »