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Are all planetary orbits elliptical?

Yes, all planetary orbits are elliptical. The exact shape does vary according to the celestial body, though. For instance, planets have elliptical orbits that appear almost circular, while comets display pronounced ellipses. The elliptical shape of any orbit is a result of the constant tension between an orbiting body’s momentum and the pull of gravity exerted by the larger body being orbited.

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