This artist’s view shows the planet orbiting the young star Beta Pictoris. This exoplanet is the first to have its rotation rate measured. Its eight-hour day corresponds to an equatorial rotation speed of 100,000 kilometers/hour — much faster than any planet in the Solar System.
Illustration credit: ESO L. Calçada/N. Risinger (skysurvey.org)
Note: For more information, see Length of Exoplanet Day Measured for First Time.