Kepler telescope spots alien solar system that looks strangely like our own

Researchers studying the star system Kepler-30, which is 10,000 light-years from Earth, found that its three known worlds all orbit in the same plane, lined up with the rotation of the star — just like the planets in our own solar system.

Cristina Sanchis Ojeda
Three known exoplanets orbit the star Kepler-30 in a configuration that is similar to our solar system’s.

Astronomers have discovered an alien solar system whose planets are arranged much like those in our own solar system, a find that suggests most planetary systems start out looking the same, scientists say.

Researchers studying the star system Kepler-30, which is 10,000 light-years from Earth, found that its three known worlds all orbit in the same plane, lined up with the rotation of the star — just like the planets in our own solar system do. The result supports the leading theory of planet formation, which posits that planets take shape from a disk of dust and gas that spins around newborn stars.

"In agreement with the theory, we have found the star's spin to be aligned with the planets," said study co-author Dan Fabrycky, of the University of California, Santa Cruz. "So this result is profound because it is basic data testing the standard planet formation theory."

Interactions among planets can later throw such ordered arrangements out of whack, researchers added, creating the skewed orbits seen in many alien systems today. [Gallery: The Strangest Alien Planets]

Planets crossing starspots

The Kepler-30 system consists of three known extrasolar planets circling a sunlike star. All three worlds — Kepler-30b, Kepler-30c and Kepler-30d — are much larger than Earth, with two being even more massive than Jupiter.

The three planets were detected in January by NASA's Kepler space telescope, which has spotted more than 2,300 potential alien worlds since its March 2009 launch. Kepler uses the "transit method," noting the telltale brightness dips caused when a planet crosses, or transits, a star's face from the telescope's perspective.

In the new study, the scientists studied Kepler observations of the extrasolar system even more closely.

Like our own sun, Kepler-30 has starspots, temporary blotches that appear dark because they're significantly cooler than the rest of the star's surface. The research team determined that all three planets transited the same starspot repeatedly, showing that their orbits must be coplanar and aligned closely with the star's spin.

In this sense, the Kepler-30 system looks like our cosmic neighborhood, which sports eight planets all lined up neatly along the sun's rotational equator. Both systems probably formed from a spinning disk of dust and gas, researchers said.

Not all exoplanet systems are so well-ordered. For example, many so-called "hot Jupiters" — giant planets that sit very close to their host stars — have off-kilter or even retrograde orbits. But hot Jupiters likely weren't born this way; rather, they were probably knocked askew by gravitational run-ins with other planets.

"We have excellent statistical properties of obliquities of stars that host hot Jupiters, and it seems to support the theories in which they are due to dynamical interactions among massive bodies," Fabrycky told via email.

The study appears online today (July 25) in the journal Nature.

More data needed

The research team stressed that the new study is a starting point of sorts. Astronomers will need more data to get a better handle on planet formation processes.

"Our work is suggestive, but we will need to observe a few more systems to show that indeed, for all coplanar systems similar to our own solar, the star's spin is aligned with the planets," said lead author Roberto Sanchis-Ojeda of MIT. "So far, we have the solar system and Kepler-30; a few more systems will be helpful to be completely sure."

Kepler should allow astronomers to study more such systems soon, Sanchis-Ojeda added.

"So far, we have identified between five and 10 new systems where we think we can apply this method, but the number is likely to grow while more data is processed," he told via email. "We are confident that we will be able to test our predictions in the next few years."

Follow senior writer Mike Wall on Twitter @michaeldwall or @Spacedotcom. We're also on Facebook and Google+.

Copyright 2012, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

You've read  of  free articles. Subscribe to continue.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to