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An illustration of a known exoplanet orbiting the star HR8799, about 130 light-years from Earth. Image courtesy NASA, ESA, and Z. Levay (STScI)
Exoplanet:
Planets that circle distant stars beyond our own solar system are called exoplanets or extrasolar planets. We currently know of nearly 500 exoplanets but astronomers are constantly discovering more of them.
