1.   And should Mount Wilson researchers discover a planet, or a planetary system still forming, the observatory will quickly recover some of its past prestige.

2.   Another planet has been discovered orbiting a distant star, and this one has the most Earth-like orbit of all.

3.   At least nine probable planets have been discovered orbiting other stars.

4.   But all these planets were discovered indirectly, by measuring very slight wobbles in the motion of the stars they accompany.

5.   In the past year, astronomers, after decades of fruitless search, have begun discovering giant planets orbiting other stars.

6.   While at least eight other planets have been discovered outside the solar system in the last two years, some astronomers question whether they are truly planets.

7.   And then there were those whose names are probably best known to their peers, including the man who discovered the planet Pluto, Clyde Tombaugh.

8.   Astronomers discover new planet.

9.   Clyde Tombaugh, the astronomer who discovered the planet Pluto, dies in Mesilla Park, New Mexico.

10.   The planets were discovered using a method that measures their gravitational pull on their star, not by direct observation.