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February 28, 2011

Two planets found sharing one orbit

Found in data from the Hubble Telescope, two planets of the same solar system have been observed as having the same orbit around there sun. Scientist believe that this discovery could help support the Bolster theory which talks about our Moon being created by Mars knocking into Earth.

The two planets are part of a four planet solar system dubbed KO1-730. They orbit their parent-star every 9.8 days at exactly the same orbital distance, though one planet is permanently 60 degrees ahead of the other.

Scientist say that this phenomena can be explained by gravitational "sweet spots." This is the idea that when one body, like a planet, orbits a more massive body, like a star, that there are located two Lagrange points along the planet's orbit where a third body can orbit stably. An example of this theory lies in our own solar system; a group of asteroids called Trojans are at similar points, of the planet described above, along Jupiter's orbit. Scientist believe that, in theory, matter in a disc of material around a newborn star can coalesce into so-called "co-orbiting" planets and that this new discovery will be able to prove this theory.

I believe that this is a great new discovery. There are so many theories of how our moon was formed, and this could be the answer. I can't wait for the arguments and discoveries that come out of this information.


Posted by mackenro at February 28, 2011 08:23 PM


I find it really interesting that half of the planets in this solar system have the same orbit. I don't know if this is the answer to how the moon was formed. Surely, we need more information but this is definitely evidence that is substantial enough to further bolster the theory that Mars (or a large object) knocked into the Earth creating our moon.

Posted by: nikraman at February 28, 2011 11:20 PM

yea this is interesting in that it references the giant impact theory,(planet size object colliding with earth to form the moon) which we learned just a while ago.It is nice to apply what we learned to new astronomy news

Posted by: chomingc at March 7, 2011 10:11 PM

Gravity is quite an amazing thing. If there is time, I think Prof Monnier might talk about the so-called "Trojan" asteroids on Friday/Monday in class (Mar 11/14).

Posted by: christoq at March 9, 2011 05:40 PM

In class we talked about how for a large body to be considered a planet, it must clear its neighborhood. In sharing an orbit, does this meet the requirement? I know this was a controversial criteria for a planet because there are even planets in our solar system that haven't really done this (ex. Neptune crossing Pluto and Jupiter sharing its orbit with the Trojan asteroids)

Posted by: nelalam at March 22, 2011 07:50 PM

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