by Jeanna Bryner And Robert Roy Britt
Planets orbit stars in the same direction that the stars rotate. They all do. Except one.
A newfound planet orbits the wrong way, backward compared to the rotation of its host star. Its discoverers think a near-collision may have created the retrograde orbit, as it is called.
The star and its planet, WASP-17, are about 1,000 light-years away. The setup was found by the UK's Wide Area Search for Planets (WASP) project in collaboration with Geneva Observatory. The discovery was announced today but has not yet been published in a journal.
What's going on
A star forms when a cloud of gas and dust collapses. Whatever movement the cloud had becomes intensified as it condenses, determining the rotational direction of the star. How planets form is less certain. They are, however, known to develop out of the leftover, typically disk-shaped mass of gas and dust that swirls around a newborn star, so whatever direction that material is moving, which is the direction of the star's rotation, becomes the direction of the planet's orbit.
WASP-17 likely had a close encounter with a larger planet, and the gravitational interaction acted like a slingshot to put WASP-17 on its odd course, the astronomers figure.
Cosmic collisions are not uncommon. Earth's moon was made when our planet collided with a Mars-sized object, astronomers think. And earlier this week NASA's Spitzer Space Telescope found evidence of two planets colliding around a distant, young star. Some moons in our solar system are on retrograde orbits, perhaps at least in some cases because they were flying through space alone and then captured; that's thought to be the case with Neptune's large moon Triton.
Please click on "external source" to access this entire article, including several interesting related links - one concerning the ten most intriguing extrasolar planets.
The following quote from The Urantia Book gives some corroboration to the scientific findings in this article.
From The Urantia Book:(bold is added by ed.)
57:5.14 All of the solar system material derived from the sun was originally endowed with a homogeneous direction of orbital swing, and had it not been for the intrusion of these three foreign space bodies, all solar system material would still maintain the same direction of orbital movement. As it was, the impact of the three Angona tributaries injected new and foreign directional forces into the emerging solar system with the resultant appearance of retrograde motion. Retrograde motion in any astronomic system is always accidental and always appears as a result of the collisional impact of foreign space bodies. Such collisions may not always produce retrograde motion, but no retrograde ever appears except in a system containing masses which have diverse origins.