11.   Long-baseline interferometry, which astronomers use to make highly accurate observations of distant objects, needs extremely accurate atomic reference clocks.

12.   The astronomers used common assumptions about the frequency of large-scale collisions with Earth to calculate the chances that a large Earth-crosser will become an Earth-collider.

13.   The astronomers used the Cerro Tololo Inter-American Observatory in Chile to measure the expanding atmospheres of five huge exploding stars, or supernovas.

14.   The dispute is rooted in the detailed, sophisticated techniques astronomers use to study stars that are only points of light, even in the biggest telescopes.

15.   The results on galaxy halos give some insight into the multifarious ways in which astronomers will be using the coming tidal wave of Sloan data.

16.   To find other solar systems, astronomers have been using an ingenious technique.

17.   To measure the rate, astronomers used telescopes to analyze light from exploding stars or supernovae.

18.   Within our own solar system, the telescope will be used by astronomers hunting for comets and asteroids and studying the weather on Jupiter, Saturn and Neptune.

19.   Quasars can shine with the brilliance of a trillion suns and astronomers can use this light to silhouette objects nearer Earth.

20.   Astronomers are using telescopes to witness events that happened a long time ago in a galaxy far, far away.