Comets have been studied for many years.
Ancient Romans saw comets as part of the atmosphere.
Even Isaac Newton has followed the progress of comets through space.
Halley's Comet is named after the astronomer Edmund Halley.
According to Halley's research, comets do not stop moving.
Halley predicted his comet's return 76 years after its appearance in 1680.
The comet was named after Halley upon its reappearance in 1756.
Halley's Comet has been called the brightest of all comets.
Today comets are observed by many scientists.
The "nucleus" of a comet is the name for its largest part.
The nucleus of a comet could be as large as 60 miles wide.
Some nuclei can be as large as 350 feet wide.
The nucleus of a comet is surrounded by gases and ice.
The glow around the comet's nucleus is called its "coma."
Does the coma make the comet fuzzy?
Honore Flaugergues first saw his comet in March of 1811.
The Great Comet of 1843 caused a panic among the British people.
The Great Comet of 1843 was considered the end of time by many frightened people.
The Chinese had observed Halley's Comet as early as 240 B.C.
Halley's Comet was last seen in February of 1986.
Many people, like me, are fascinated by comets.
4. is named
5. do stop
7. was named
8. has been called
9. are observed
12. can be
13. is surrounded
14. is called
15. Does make
18. was considered
19. had observed
20. was seen