1.   Another question is why only one large planet has been found around each of the four stars.

2.   But the unsettling gravitational forces from such large planets in close proximity could have cleared the neighborhood of smaller bodies.

3.   For example, astronomers have observed that some stars seem to dim as large orbiting planets pass in front of them.

4.   Most astronomers believe such a large planet can only have formed much farther out, and spiraled in.

5.   Scientists discovered for the first time three large planets spinning around a star.

6.   Somewhere along the way, Jupiter snared Shoemaker-Levy away, and the comet began orbiting the large planet rather than the sun.

7.   That wobble, they determined, was being caused by a large planet racing around the star in a tight, four-day orbit.

8.   The gravitational influence of the large planets flung these cosmic gypsies to even further distances where they now swarm in formations called the Oort Cloud and Kuiper Belt.

9.   The spacecraft also found evidence that Ganymede is generating its own magnetic field, common for large planets but never before detected around a moon.

10.   This could have led to the rapid creation of a large planet at about the same time its parent stars were born.