2.2 Comets And Meteors

Question 1

What is a comet

Answer 1

A ball of rock and ice that form tails in the course of they orbit around the sun

Question 2

What’s a comets orbit like

Answer 2

Highly Elliptical

Question 3

When does a comet develop a tail

Answer 3

As they approach the sun

Question 4

What is a comet tail like

Answer 4

An ion points in the opposite direction to the sun

A dust tail follows the way the comet is moving - sticks out behind

Question 5

What are the 2 types of comet

Answer 5

Short period comets

Long period comets

Question 6

Tell me some stuff about short period comets

Answer 6

originate from the Kuiper belt (30-50 au from sun) beyond Neptune and have a life of less than 200 years

Question 7

Tell me some things about long period comets

Answer 7

Long period comets originate from Oort Cloud which is about 50,000 au from sun

Life more than 200 years can be millions

Question 8

What do observations of long period comets indicate

Answer 8

Orbits often highly inclined to the ecliptic

Question 9

What happens to a comet when is approaches the sun

Answer 9

Temperature rises

Gas and dust form a coma (atmosphere)

At even closer distance 2 tails can be developed

Question 10

What is an ion tail like?

Answer 10

Faces opposite way to sun

Blue coloured

Consists mainly of carbon monoxide that has been ionised by solar wind

Question 11

What’s ionise

Answer 11

Convert atom, molecules or a substance into ions

Question 12

What’s a dust tail

Answer 12

A shorter, broader slightly curved tail

Produced by radiation pressure that pushes particles out of nucleus,

Tail stick out behind direction of motion

Question 13

How long can tails be

Answer 13

Several millions of kilometres long

Question 14

What is a meteor

Answer 14

A small body of matter from outer space that enters earths atmosphere becoming incandescent which then looks like a streak of light due to friction

Shooting star

Question 15

What’s a meteoroid

Answer 15

A small body moving in the solar system taming from micrometres to several metres

Usually orbit at speeds of 40km/s

Question 16

Where do meteoroids originate from

Answer 16

Dust tails of comets forming meteoroid streams/showers

Question 17

Meteors with a magnitude of -3 or less are called….

Answer 17

Fireballs

Question 18

What’s a meteorite

Answer 18

If a meteoroid survives through the atmosphere and lands in the earths surface it’s a meteorite

Question 19

What 3 categories are meteorites classified into

Answer 19

Stones

Irons

Stony irons

Question 20

What is the radiant

Answer 20

The point where meteors seem to diverge from this point in the sky even though they are actually travelling parallel

Question 21

How is a meteor shower named

Answer 21

After the constellation the radiant is found

Question 22

What is a PHO

Answer 22

Potentially hazardous object

Have orbits that bring them closer to us than 0.05 AU

Question 23

What’s a near earth object? (NEO)

Answer 23

An object whose trajectory might bring them closer than 0.3 AU

Question 24

Name some examples of solar system collisions

Answer 24

The moon - covered with impact craters from asteroids

Venus and Uranus rotate backwards and sideways and likely due to a gigantic collision in early solar system history

Barringer crater in Arizona

Tunguska event

Question 25

What diameter of PHOS pose the biggest threat

Answer 25

1km+ - could cause a catastrophe on global scale

Question 26

What is the Torino scale?

Answer 26

Used to categorise impact hazards

Like Richter scale for earth quakes, number 0-10, 0-1 likely miss

8,9,10 certain collision, capable of regional or world wide devastation

Question 27

How do we know the Oort Cloud is for real

Answer 27

We see Kuiper belts in other solar systems so the Oort Cloud could be s continuation of a Kuiper belt

Solar system formation models predict that the formation of the giant planets would have scattered small icy objects into the outer solar system. While some would be given enough energy to completely escape the solar system, others would be scattered out to the hypothetical Oort Cloud.

Question 28

What’s a mircometeorite

Answer 28

A meteorite that can land to the surface without lighting up- becoming incandescent

Question 29

If A PHO HIT earth what

Could happen

Answer 29

So much dust and debris would be thrown up into atmosphere there would be no sunlight - lowering temperatures and perhaps extincting life