Lecture #10 -Meteorite Impacts

Question 1

How was the solar system formed?

Answer 1

Cloud of Gas and dust in space was disturbed by a supernova

4.6 billion years ago

Question 2

What is Nebular Hypothesis?

Answer 2

The explosion made was in space. This caused the formation of a solar nebula ( a flattened cloud of gas and dust)

Question 3

What is a super nova?

Answer 3

Explosion of a star

Question 4

How were the planets formed?

Answer 4

caused from the centre of the solar nebula grew hotter resulting int he formation of the sun
-the edges cooled causing clumps of particles that stick together and form planets

Question 5

Whats a galaxy?

Answer 5

A cluster of billions of stats

Question 6

Whats a star?

Answer 6

A hot glowing ball of gas that generates energy by converting H–>He

Question 7

How long does it take to travel from one side to the other of the galaxy?

Answer 7

~100,000 lightyears

Question 8

What is the temp in the middle of the sun?

Answer 8

15 million Degrees C

Question 9

What is the photosphere?

Answer 9

Outermost part of the sun

-6000 degrees C

Question 10

What controls the earths climate system

Answer 10

energy from the sun

Question 11

What is the order of the 8 planets?

Answer 11

Mercury-Venus-Earth-Mars-Saturn-Jupiter-Uranus-Neptune

Question 12

Why is Pluto not a planet?

Answer 12

Because there are a lot of other bolides that circle the solar system, that are the same size of Pluto and we don’t consider them planets so we took them out

Question 13

What happens at the end of a stars lifecycle?

Answer 13

They grow bigger until they explode and massive amounts of energy is released

Question 14

What is a bolide?

Answer 14

Extraterrestrial bodies that originate in outerspace

Question 15

What is an Asteroid

Answer 15

A rocky metallic material in space 10-100m in diameter originating in the asteroid belt

Question 16

What is a Meteoroid?

Answer 16

Smaller objects in space up to 10m in diameter

Question 17

What is a Meteor?

Answer 17

A meteoroid that has entered earths atmosphere

Question 18

What is a Meteorite?

Answer 18

A meteor that strikes the earth surface

Question 19

What is a comet?

Answer 19

These are distinguishable by a glowing tail of gas and dust

Question 20

What are comets made from?

Answer 20

gas and ice and has a rocky core

-they create the light as gases are released

Question 21

What is an air burst?

Answer 21

Bolide that travel at velocities of 12-72km/s. They enter the atmosphere and explode at an altitude between 12-50 km above the surface

Question 22

The Tunguska Airburst

Answer 22

Destroyed a lot of forest in 1908
-no crater was found so it was deemed and air burst
-asteroid was probably ~25-50m
0shockwave produced the airburst

Question 23

The Chelyabinsk Airburst

Answer 23

Feb 15 2013
Meteor exploded over a city in Russia
1500 people injured due to broken glass

Question 24

What is an ejecta blanket?

Answer 24

Layers of debris consists of rock fragments that were blow out of the crater on impact

Question 25

Why arent todays craters as deep?

Answer 25

Because of erosion and weathering over time

Question 26

Barringer Crater?

Answer 26

50 000 years old located in Arizona Hole filled in over time due to wind and erosion Shockwaves blew out the material

Question 27

What are simple craters?

Answer 27

Less than a few km | Doe not have an uplifted centre

Question 28

What is a complex crater?

Answer 28

Rim collapses under extreme faulting Centre flood that rises following impact greater than 6km

Question 29

Chesapeak Crater?

Answer 29

discovered by surface imaging Formed 35.5 million years ago didnt overlain with ocean and sediments

Question 30

Why are craters more common on the moon?

Answer 30

- Most impacts occur in the ocean so no crater is produced - most have eroded away - smaller bolides burn up in the atmosphere

Question 31

Shoemaker Level comet

Answer 31

Entered Jupiters atmosphere in 1994 released massive amounts of energy -this could happen to us one day too destroying everything

Question 32

What is the K-T boundary Mass extinction?

Answer 32

- 65 million years ago, an asteroid impacted the earth, ending the dinosaurs - Found large amounts of Iridium (uncommon on earth but common in space) - Crater discovered in 1991 in yucatan Peninsula Mexico under sediment and ocean - asteroid was prob ~10km

Question 33

Where to asteroids have to stay in order for them not to pose a risk to us?

Answer 33

Mars and Jupiter Asteroid belts

Question 34

how do we disturb an asteroids path?

Answer 34

Blowing it up or hitting it with another asteroid | -nuclear explosions