Unit 4

Question 1

Where in our solar systems do many asteroids reside?

Answer 1

In the Asteroid Belt, between Mars and Jupiter

Question 2

Why is there an asteroid belt? How did it form?

Answer 2

It represents the material that never assembled into a planet

Question 3

Are all meteorites from the asteroid belt?

Answer 3

No, we also have meteorites from Mars and the Moon. Not so much from Venus, the trajectory will always be toward the greatest gravitational attraction, which is the Sun

Question 4

What does the Titius Bode Law allow us to predict?

Answer 4

The predicted planet spacing in AU

Question 5

Why is it important to learn about asteroids?

Answer 5

1. They represent very primitive material left over from formation of the Solar System 2.Much water and organic material came to Earth from them 3. Sooner or later a large asteroid impact is likely to put an end to many terrestrial species (including humans)

Question 6

Where are most asteroids found in the solar system?

Answer 6

In the Main Asteroid Belt

Question 7

What are asteroids and meteorites thought to represent? (e.g. age and material)

Answer 7

Meteorites shows that asteroids are the last remain of the planetesimals that built the planets 4.57B years ago

Question 8

Why did the asteroid belt form between Mars and Jupiter?

Answer 8

Jupiter’s has such a large mass that its gravity dramatically affects the motions of small bodies anywhere close to it

Question 9

If all the meteoroids and asteroids in the main asteroid belt coalesced, would there be an additional Earth-sized planet between Mars and Jupiter?

Answer 9

No, because Jupiters gravity prevents these objects to coalesced

Question 10

Why are some asteroids metallic while others are not?

Answer 10

????

Question 11

Are the most primitive asteroids closer to Mars or Jupiter?

Answer 11

Jupiter

Question 12

Why are the most plentiful asteroid types (carbonaceous chondrites) the least common meteorites found on Earth?

Answer 12

????

Question 13

What is a differentiated body?

Answer 13

Means that they have been heated, by radioactive decay and from the energy released during accretion, enough that their interior starts to melt

Question 14

Give an example of the kinds of features the spacecraft Dawn has observed on large asteroids.

Answer 14

Physical measurements revealed that it has a metal-rich core that is approx. 220m in diameter for Vesta

Question 15

When two asteroids of unequal size collide, will the fragments come from the larger body or the smaller one?

Answer 15

From the larger body because the smaller one would probably melt

Question 16

Do Near Earth Objects have circular or elliptical orbits?

Answer 16

HIGHLY elliptical

Question 17

What size of an impactor could cause global effects on Earth?

Answer 17

Larger than 1km in diameter

Question 18

What does it mean as numbers increase on the Torino Scale?

Answer 18

Scale of 0-10 to describe the level of concern of a certain event

Question 19

What are the sources of meteorites that we have found on Earth? How representative of the sources are the samples?

Answer 19

???

Question 20

Of Irons, Stony-Irons, and Stones, which is most commonly found on Earth?

Answer 20

Stones

Question 21

How are chondrules formed?

Answer 21

They condensed from a hot cloud of gas and dust, very early in the Solar System history, by a ‘flash-melting’ of dust aggregates in the solar nebula

Question 22

Why are scientists so excited about studying carbonaceous chondrites?

Answer 22

Taken as a whole their composition more closely matches that of the Sun than any other material we have to examine

Question 23

What are the possible sources of micro-meteoroids (a.k.a. interplanetary dust)

Answer 23

Composed of silicate minerals???

Question 24

How does a meteor shower occur? What is the difference between a meteor shower and a fireball?

Answer 24

They come from very specific regions of the sky, and travel together in space in the same direction along a common orbit. Different from a fireball because most meteoroids that produce fireballs are massive enough to survive atmospheric passage, often explosively disintegrating into several smaller pieces en-route while a meteor shower would never survive to reach Earth’s surface

Question 25

How is the light of a fireball formed? Why do the colours change?

Answer 25

The burning of the solid body itself and the Incandescence of the atmosphere immediately around the burning mass. Colours come from the composition of the vaporizing material and the luminous air surround the hot meteoroid

Question 26

Are meteorites hot when they land? Why or why not?

Answer 26

No they are actually quite cold, cause the melting phase doesn’t last long enough for heat to reach the interior

Question 27

How does the atmosphere slow a meteoroid’s momentum?

Answer 27

By creating a drag on it, thus slowing its velocity, further reduces it momentum by heating the meteoroid until it begins to lose mass by the ablation process

Question 28

Explain how a meteoroid’s mass and velocity affects its momentum and kinetic energy

Answer 28

The more mass the body has or the faster it is travelling, the greater the force necessary to change its state of motion, the greater a meteoroid’s mass and velocity, the greater the kinetic energy

Question 29

Many meteors are destroyed in the atmosphere before the reach the Earth’s surface – what kinds of meteors (size, speed) are more likely to survive?

Answer 29

Stony meteoroid, especially on the forward end, is sufficient to cause the mass to break into several smaller pieces. These pieces have a better chance of survival than the larger single mass, since smaller stones with less mass are more readily slowed in the atmosphere, therefore suffering less heating and ablation

Question 30

How does atmospheric friction affect the surface of the meteorite?

Answer 30

Small fragments may largely or totally melt

Question 31

Where are meteorites on Earth often found and why?

Answer 31

In the desert regions of Morocco, Oman and Antarctica because its easily spotted

Question 32

What techniques do we use to analyse a meteorite? What can we learn from these tests?

Answer 32

??