Orphaned planet and twin Earths that 'could share life' revealed

Take HD-106906b, or "fat Jupiter" as some observers have termed it.

A planet far larger than our incredibly massive neighbor which has become partially exiled from its solar system, ending up nearly 16 times farther away from its host star than Pluto is from the sun.

Fat Jupiter may have formed near the star like a normal world, before getting booted out to the very edges of the system by a dramatic event in the recent galactic past.

"We think the whole [fat Jupiter] system has recently been disturbed by some violent gravitational interaction, though we're not sure exactly what happened," said Paul Kalas, an adjunct professor of astronomy at the University of California at Berkeley.

"Something recently happened that kicked it out."

A similar event may have occurred in the distant history of our own solar system.

Scientists believe that we once shared our part of the Milky Way with a ninth planet (or tenth, if we're counting Pluto) before Jupiter's huge gravitational pull sent the other planet spinning out into the wastes of intergalactic space.

Extreme solar systems

Kalas was speaking at a press event for the Extreme Solar Systems (ExSS) conference taking place this week in Waikoloa Beach, Hawaii.

The conference, the third of its type since 2007, brings together 350 of the world's leading space scientists to discuss "every aspect of exoplanet research", according to American Astronomical Society Director of Communications Rick Feinberg.

Feinberg pointed out that the conference was being held at special time, the 20th anniversary of the discovery of 51 Pegasi b, the first planet outside our solar system found orbiting a sun-like star.

"51-Pegasi b is now part of history," Feinberg said.

Though the gassy, tidally-locked and incredibly hot 51-Pegasi b doesn't present much hope for life outside our solar system, other findings presented at the conference are may well do.

Twinned planets sharing life

While Earth is the only planet in our neighborhood that lies in the "Goldilocks zone" -- the area close enough to our star to get enough warmth but not so close it's roasted -- other solar systems may have two or more in the habitable area.

This could actually be an advantage when it comes to developing life, according to the University of Nevada's Jason Steffen and Gongjie Li of the Harvard-Smithsonian Center for Astrophysics.

"You're no worse off by having a neighboring planet that's also in the habitable zone," Steffen said at ExSS.

In fact, there may be significant upsides. Steffen and Li found that two inhabitable planets could easily share microbes and other material of life, assisting in the development and evolution of organisms on both worlds.

"Life in a multi-habitable system may have a higher probability of surviving," said Steffen.

Steffen and Li's theory builds on the concept of panspermia, that our own planet may have been "seeded" with life from meteorites, asteroids and other ejecta from far-away worlds.

Last month, scientists announced the discovery of GJ-1132b, "arguably the most important planet ever found outside the solar system", which may support basic forms of life such as bacteria.

(CNN)