科学美国人60秒:System Has Multiple Planets Off Kilter

Our solar system stretches out over billions of miles. But it’s relatively flat, with all the planets more or less in line with the sun’s equator. Now we know about another solar system that lives by a different set of rules. And it may help straighten out some mysteries about how planetary systems form.

Astronomers using NASA’s Kepler space telescope analyzed a giant star called Kepler 56, about 3,000 light-years from Earth. And they found that two of its three known planets orbit at a severe tilt. [Daniel Huber et al, Stellar Spin-Orbit Misalignment in a Multiplanet System, in Science]

Such skewed orbits are common for so-called hot Jupiters—gas giants that orbit close to their hosts. But the Kepler 56 system is the first one known where the orbits of multiple planets are out of alignment with their star’s equator.

Astronomers think a large, hidden third planet recently found lurking in the Kepler 56 system might have pushed the other two planets off course. Similar interference could be behind many misaligned hot Jupiters throughout the galaxy. Clearly, there’s more than one way to build a solar system.

—Clara Moskowitz

[The above text is a transcript of this podcast] 

Also see Kepler Exoplanet Hunter Limps into Sunset