Discovering the planet in paradox

Astronomers in the UK have found the first planet to turn against its own star.

The star forms when a cloud of dust and gas shrinks, causing its own mass to increase (gravitational contraction). The direction of matter in the cloud determines the direction of rotation of the star. The planets also formed from the created cloud so scientists always thought they had to rotate in the same direction as stars.

Strange planet, named WASP-17b , and its star about 1,000 light-years from Earth. Scientists from the British Search for Extrasolar Planets (WASP) project have found the duo. The new planet has a mass of half Jupiter but its size is twice as large. Its level of material shrinkage is 70 times less than that of the earth. It is possible that the elliptical orbit makes WASP-17b so big, because with such an orbit the distance between the planet and the star changes constantly. Sometimes he came close to the star and then back away very far.

The planet moves in the opposite direction of the star as a very rare phenomenon in the universe.(Photo: shm.com.au)

" I'm sure this is one of the strangest planets we've ever known, " said astrophysicist Sara Seager of the Massachusetts Institute of Technology. Seager did not participate in the WASP project.

WASP-17b is one of the 17 planets that the WASP project found outside the solar system . According to astronomers, it is likely that it has been near a larger planet or star . Gravity from the other object causes its rotation to reverse.

" If two celestial bodies almost collide with each other, the gravitational force from a larger body will affect the opponent's rotation ," explained Coel Hellier, a scientist at Staffordshire University (UK).

Objects in the universe rarely collide with each other. Astronomers believe that the moon formed when the earth collided with an object the size of Mars. Earlier this week the Spitzer space telescope found evidence of a two-planet collision around a distant star. Some satellites in the solar system also have reverse trajectories. Scientists predict that they used to roam in space before being 'caught' by a planet. Neptune's Triton satellite is one of those reverse-rotating satellites.