1.   Early astronomers thought that our planet was the centre of the universe.

2.   And astronomers think the fun has just begun.

3.   Astronomers had thought that gas in the vast spaces between the galaxies would be in clumps or clouds, with empty space in between.

4.   Astronomers once thought the gravitational pull of small bodies like asteroids and comets to be too slight to hold onto moons.

5.   Astronomers think that such hot, ultraviolet-emitting stars in all globular clusters have the same intrinsic brightness.

6.   Astronomers think these star-sized black holes form from the death of an ordinary star that has consumed all its nuclear fuel and collapsed.

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

8.   Astronomers think they have an explanation.

9.   Astronomers think they have solved the mystery of the strange object that has confounded them ever since its discovery three years ago.

10.   At least, astronomers think it was a false alarm.