Comets

Question 1

What is a comet?

Answer 1

Comets are cosmic snowballs of frozen gases, rock and dust that orbit the Sun.

Question 2

What happens when they pass by the sun?

Answer 2

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.

Question 3

How many comets are there?

Answer 3

3,591

Question 4

How are comets born?

Answer 4

Dust and gas of Protoplanetary disk. on the fringes of the disk, fine grains of dust coated with frozen gases and water ice began clumping together

Clump of dust assembled into ice-rich rocks

Evolved into the mile-sized bodies

Question 5

Composition of a comet

Answer 5

1950-Fred Whipple proposed a model which explained most physical characteristics: 
Nucleus
Tails
Coma
Halo

Question 6

Orbits

Answer 6

Elliptical orbit

Kepler’s Law: closer to sun=faster

Question 7

Famous comet

Answer 7

Haley Comet.
Shoer period (less than 200 years to orbit the sun)
Returns to Earth every 76 years

Question 8

Long Period

Answer 8

comets can take as long as 30 million years to complete one trip around the Sun.

Question 9

How comets get their name?

Answer 9

P/indicates a periodic comet
C/indicates a non-periodic comet
X/indicates a comet for which no reliable orbit could be calculated
D/indicates a periodic comet that has disappeared, broken up, or been lost
A/indicates an object that was mistakenly identified as a comet, but is actually aminor planet.
I/indicates an interstellar object.