Reverse orbits could make Earthlike neighbors unlikely
A bevy of backward-orbiting exoplanets could challenge theories of planet formation, new research suggests. The planets’ wonky orbits might also rule out the presence of Earthlike bodies in some planetary systems.
The wrong-way planets got where they are by cartwheeling over their stars’ heads, Andrew Collier Cameron of the University of St Andrews in Scotland proposed in an April 13 presentation at the Royal Astronomical Society’s National Astronomy Meeting in Glasgow, Scotland.
Planets are thought to form from the disk of gas and dust that surrounds a young star. Because the star and the disk both coalesce from the same cloud of material, theory holds that both should spin in the same direction &mdash