Rogue orbit of planet Fomalhaut b could lead to crash in 2032

Newly-released Hubble images of the Fomalhaut system, which was called 'Eye of Sauron' by some, shows a vast debris belt which is wider than previously known, and hosts a rogue planet on a potential collision path.

The material reveals that the planet, Fomalhaut b, follows a very eccentric orbit, and might even follows a potentially destructive path. The 2,000-year-long orbit swings as close to the star as 7.4 billion kilometers, and as far away as 43.5 billion kilometers.

"We are shocked. This is not what we expected," says Paul Kalas of the University of California at Berkeley and the SETI Institute in the release.

The team now suggests the scenario that there might be other planet-like bodies in the system that either collided with, or otherwise gravitationally disturbed Fomalhaut b to place it in such a long and elliptic orbit. There could be another, yet undiscovered large planet in the inner region of the system, which "kicked out" Fomalhaut b. Another option is that a hypothetical second dwarf planet suffered a catastrophic collision with Fomalhaut b and altered the orbit.

"Hot Jupiters get tossed through scattering events, where one planet goes in and one gets thrown out," says Mark Clampin of NASA's Goddard Space Flight Center. "This could be the planet that gets thrown out."

Another discovery from the new material shot by the Hubble telescope is that the planet's orbit could lie in the same plane as the massive dust belt, which Fomalhaut b will intersect with around 2032 on the outbound leg of its orbit. During the crossing, icy and rocky debris in the belt could crash into the planet's atmosphere and create the type of cosmic fireworks seen when Comet Shoemaker-Levy 9 crashed into Jupiter - but most of that in infrared light. And if Fomalhaut b isn't in the same plane as the belt, all that will be seen is a gradual dimming of the planet as it travels farther from the star.

The Fomalhaut system is special, says the team, because it looks a lot like our own solar system could have looked like 4 billion years ago. The planetary architecture is being redrawn, the comet belts are evolving, and planets may be gaining and losing their moons.