1.   Johannes Kepler was the first person to realize that the planets orbit the Sun in just such paths.

2.   The planet Mercury orbits the Sun more closely than do any of the others.

3.   All the planets orbit the Sun in roughly the same plane, round its equator.

4.   Preliminary evidence suggested that a second planet was also orbiting the star further out.

5.   The planets orbit around the sun.

6.   And the planet is orbiting both stars at a distance about seven times that of the Earth-Sun distance.

7.   As far as scientists know, other, smaller planets may orbit these stars.

8.   Astronomers think they understand much about how the universe began, why stars shine and galaxies take majestic shape, and where planets orbit other stars.

9.   But NASA says solar-electric cells become inefficient in the outer solar system, far from the Sun, where the ringed planet Saturn orbits.