Comets are icy objects that orbit the sun. When close to the sun, they heat up and develop a glowing head and tail. Comets are typically named after their discoverer, such as a person or spacecraft. The most famous comet is Halley's Comet, which returns about every 75 years. It is named after Edmond Halley, who realized it was a periodic comet by examining sightings from the early 1600s and predicting its 1758 return.

1.  Comets are cosmic snowballs of frozen gases, rock and dust that orbit
the Sun. When frozen, they are the size of a small town.
 When a comet's orbit brings it close to the Sun, it heats up and spews
dust and gases into a giant glowing head larger than most planets. The
dust and gases form a tail that stretches away from the Sun for millions
of miles.
 There are likely billions of comets orbiting our Sun.

3. HOW COMETS GET THEIR NAMES?
 Comet naming can be complicated.
 Comets are generally named for their discoverer—either a person or a
spacecraft.This International Astronomical Union guideline was developed only
in the last century.
 For example, comet Shoemaker-Levy 9 was so named because it was the ninth
short-periodic comet discovered by Eugene and Carolyn Shoemaker and David
Levy.
 Since spacecraft are very effective at spotting comets many comets have
LINEAR, SOHO orWISE in their names.

4. Halley's Comet is arguably the most famous comet.
 It is a "periodic" comet and returns to Earth's vicinity about
every 75 years, making it possible for a human to see it twice
in his or her lifetime. The last time it was here was in 1986,
and it is projected to return in 2061.
 The comet is named after English astronomer Edmond
Halley, who examined reports of a comet approaching Earth
in 1531, 1607 and 1682. He concluded that these three
comets were actually the same comet returning over and over
again, and predicted the comet would come again in 1758.
 Halley didn't live to see the comet's return, but his discovery
led to the comet being named after him. Halley's calculations
showed that at least some comets orbit the sun.
Halley’s Comet