1.   Astronomers have observed many systems in which two stars orbit around each other, attracted toward each other by gravity.

2.   Astronomers repeatedly observed two jets of gas shooting out at opposite sides and perpendicular to the disk of rotating matter around the protostar.

3.   Astronomers on Earth observe comets rushing through the inner solar system only fleetingly.

4.   Comets are the smallest objects astronomers have observed around other stars.

5.   Every stage in the life of this type of star is represented by many examples available in the sky for astronomers to observe and measure.

6.   For a long time, astronomers have observed stars in formation, because it is a process continuing through time.

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

8.   In time, astronomers observed two strange phenomena.

9.   Still, astronomers cannot observe the objects themselves, only their effects on nearby stars, gas and dust.

10.   The astronomers have observed such evidence of ice on some of the other Kuiper Belt objects.