Free-floating planets not as common as thought?
More than 3500 extrasolar planets have now been detected; the study of these extrasolar planets and our own solar system is one of the most exciting areas in astrophysics. Virtually all of these planets are found around other stars. For example, our Earth orbits around the Sun. However, theory predicts some planets are either formed or ejected from proto-planetary disks because of dynamical interactions during their formation. These planets are called free-floating or rogue planets (see the cover illustration).
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