Comets

By: Kaya Umeda, Cierra

Yoshikawa

What is a Comet?

• Small, icy celestial body that orbits

around the sun

Comet Parts

• Nucleus (ice, gas and

dust)

– Most of comets mass

• Coma (water vapor,

CO2, and other gases)

– Surrounds nucleus

• Nucleus and Coma form

the head

Parts Cont.

• Ion Tail (gas)

– Approaching sun, trails

comet

– Leaving sun, leads comet

• Dust tail (dust)

– Long, wide tail composed

of microscopic dust

particles

Comet Path

• Travel in elliptical

orbits

• Velocity increases

near sun

• Visible near sun

Comet Life Cycle

• Departure:

– Some are not bound to the sun

• Extinction:

– Lose ice and dust each time they come near

the sun.

– They can lose all their ices and turn into

fragile similar to asteroid

Comet Life Cycle Cont.

• Breakup:

– Comets that lose all their ices break up

and dissipate into clouds of dust

• Collisions:

– Orbiting comets can collide with planets

and moons

Characteristics

• Short-period comets:

– Need about 200 yrs or less to complete

one orbit

– Originate from a disk-shaped band of icy

objects

Characteristics cont.

• Long-period comets:

– Takes more than 200 yrs

– Comes from the nearly spherical Oort

cloud even further out, which get slung

inward by gravitational pull of passing

stars

Comet Names

• Comet Halley- most famous comet

• Comet Neat

• Comet Kohoutek

• Comet Hyakutake

Cosmic Snowballs

• New theory that comets are

composed of frozen water are

constantly bombarding Earth

• Vaporize in the atmosphere, adding

water vapor to environment

Works Cited• “Comets.” All About Astronomy. N.p. 1999. Web. 11 Jan 2011.

<http://www.enchantedlearning.com/subjects/astronomy/comet/>

• “Comets.” The Nine Planets. N.p., 1994. Web. 11 Jan 2011.

<http://nineplanets.org/comets.html>

• “Comets: Formation, Discovery and Exploration.” Space.com. N.d.

Web. 11 Jan 2011.

<http://www.space.com/53-comets-formation-discovery-and-

exploration.html>

• Hamilton, J. Calvin. “Comet Introduction.” View of the Solar

System. N.p. 1995. Web. 11 Jan 2011.

<http://www.solarviews.com/eng/comet.htm>