CHZ

Question 1

Four ways to define a habitable planet?

Answer 1

Liquids
Suitable star
Atmosphere
Suitable gravity

Question 2

Important factors to produce life

Answer 2

Chemical elements
Liquids
Gravity
Heavy elements
Collision impacts
Presence of nearby planets
Plate tectonics

Question 3

Of the 92 naturally occuring elements how many play a role in terrestrial life?

Answer 3

21

Question 4

What are the major biogenic elements?

Answer 4

C, H, O, N, Mg, Ca and Cl

Question 5

Why are H O N and C most significant?

Answer 5

Able to achieve electronic stability easily

Question 6

Why are liquids necessary?

Answer 6

Place for molecules to interact
Need polar solvent to establish H bonds

Question 7

Why does temperature need to be suitable?

Answer 7

Allows reactions to occur and organic bonds to form

Question 8

What if temperature is too high?

Answer 8

All moisture will evaporate causing greenhouse effect

Question 9

What if temperatures are too low on planey?

Answer 9

Planet could have permanent ice age

Question 10

What happened to venus and its temperature?

Answer 10

Greenhouse effect has dried up surface and raised temperatures to 460 degrees due to insulating atmosphere

Question 11

What is the Circumstellar habitable zone?

Answer 11

The region around a star within which planets can support liquid water at their surfaces

Question 12

What can massive ice formation lead to on Earth?

Answer 12

Snowball earth where albedo of surface goes up causing even further cooling

Question 13

Surface temperatures needed to liquid water

Answer 13

273 K to 373K

Question 14

What will affect the CHZ?

Answer 14

Long-term stellar variability such as sun becoming larger and brighter

Question 15

Why are lots of liquids needed?

Answer 15

Produce large pools to circulate vital minerals and elements

Question 16

How does the gravity need to be for life?

Answer 16

High enough to retain an atmospheric pressure large enough to prevent liquids from evaporating.

Question 17

Moon Atmosphere and Gravity

Answer 17

Gravity is 1/6 Earth so cant hold atmosphere and high day temperatures mean surface water would evaporate in the day

Question 18

Mars Gravity and Atmosphere

Answer 18

62% lower than earth
Holds a thin Co2 atmosphere so little insulation so surface temp is very low -50 degrees

Question 19

Why are heavy elements needed?

Answer 19

Needed to form rocky planets

Question 20

Which type of stars are heavy elements found in?

Answer 20

All Population - 1 type stars
Not in sufficient amounts in Population - 2 stars

Question 21

What percent heavy elements is needed to form rocky planets?

Answer 21

1-2%

Question 22

Where are Population 2 stars found?

Answer 22

Centre of the galaxy and unlikely to have few rocky planets

Question 23

How can impacts influence life?

Answer 23

Kill life
Also maybe key to introduce new ingredients

Question 24

How can the gas giants influence the impact rate?

Answer 24

• attract most of the loose solar system debris to protect rocky planets
• disrupt debris from stable orbits and send it towards rock planets

Question 25

How does moon influence planet?

Answer 25

Acts as stabiliser for planet spin
Encourages tidal activity that can encourage life diversity

Question 26

How much is the moon moving away?

Answer 26

3.8cm per years

Question 27

How does moon slow earths rotation?

Answer 27

Friction pushes tidal bulge in direct of earths rotation and moons gravity pulls it back slowing the rotation

Question 28

When will moon stop stabilizing our axis?

Answer 28

1-2 billion yrs

Question 29

How has plate tectonics influenced in recycling components?

Answer 29

Carries stored Co2 in shells back into the mantle and via volcanic activity its released back into the atmosphere

Question 30

How have plate tectonics influenced land?

Answer 30

Lead to natural terraforming to increase the quantity of available land since earths formation

Question 31

How was atmosphere first formed?

Answer 31

Outgassing from volcanoes