Actually there are lots of other planets/galaxies. You have the 8 planets plus the five official dwarf planets (Ceres, Pluto, Eris, Makemake, and Haumea.) of our solar system. And 77 known extrasolar planets. As for how many galaxies are in the univirse. There's 3,000 visible galaxies and The Hubble Space Telescope site estimates there are hundreds of billions of galaxies in the universe. A German super-computer simulation estimates that the number may be as high as 500 billion.
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