(SEM1Q1, SCI) 4.1 - Comets

What is a comet?

a small body of ice, rock, and dust that follows a highly elliptical orbit around the snu

As a comet passes close to the sun, what does it give off? (2)

gas and dust

Where does a comet get its light from?

the sun

What does the speed of a comet depend on?

how far or how close it is to the sun (because if it's closer, its orbit is smaller; making it faster)

What elements can comets contain? (2)

sodium or argon

What element is Comet Hale Bopp made up of?

argon

Why was Comet Hale Bopp very bright?

due to argon

What did the astronomers believe in based on the composition of comets?

it was made of remains from when the solar system was formed

What are the two main regions where comets can be found in?

kuiper belt, oort cloud

What is the oort cloud?

region that surrounds the solar system and extends almost halfway to the nearest star

What are the 4 parts of a comet?

nucleus, coma, ion tail, dust tail

What is the nucleus composed of?

ice and rock

What happens when a comet approaches the sun?

solar radiation and heating cause the comet's ice to change into gas

What is a coma?

a spherical cloud of gas and dust that comes off of the nucleus

What is an ion tail?

gas that has been ionized or stripped of electrons from the sun

How does the solar wind affect the ion tail?

it pushes the gas away from the comet's head

In what direction does the ion tail point travel?

away from the sun

What is the dust tail?

a second tail made of dust and gas that curves backward along the comet's orbit

What is the Kuiper Belt?

a ring of icy bodies just outside of Neptune's orbit

Where do short-period comets originate?

Kuiper Belt

Where do long-period comets originate?

Oort Cloud

What do collisions between objects in the Kuiper Belt produce?

fragments that become comets

What is a short-period comet?

comets that take less than 200 years to orbit the sun with short life spans

What happens when a comet passes the sun?

It may start melting or losing its layers.

What is the famous comet and is the only known short-period comet?

Halley's Comet

How long does it take for Halley's comet to complete its orbit around the sun?

75 years

When can we see Halley's Comet again?

2061

How are comets formed in the Oort Cloud?

when two objects collide

What are long-period comets?

takes hundreds of thousands of years to orbit the sun

What comet has been speculated to be the Star of Bethlehem?

Halley's Comet