Fastest planets in space

The laws of gravity mean the closer a planet orbts its star, the faster it must move in its orbit. Our home world is moving along its orbit at a median speed of 29.8 kilometres (18.5 miles) per second, while Mercury has a fair higher top speed of 59 kilometres (37 miles) per second. But these speeds are nothing compared to the fastest moving planets in our galaxy so called ultra-short period planets, or USPPs, which orbit their stars in mere some hours. The fastest-known planet of this sort, called kepler-7ob, is assumed to be the exposed solid core of a planet that was once like jupiter, and orbits its star at a mean of 272 kilometres (169 miles) per second.

No planet could ever form in such an extreme orbit, so astronomers believe that instead, these gas giants originated much farther move into their solar systems, then spiralled inward through interacting with leftover material in clouds of plnet-forming material. a number of these 'hot jupiters' meet their doom by crashing into their parent stars. Rogue planets, kicked out of their planetary systems by the identical process that makes hypervelocity stars (see over page), can even achieve great speeds.