Lesson 1 - Earth as a Unique Planet

Question 1

the only planet in the universe that can support life

Answer 1

earth

Question 2

six things that make life on earth possible

Answer 2

1. our location is far from many hazards
2. our sun is a stable and long-lasting star
3. we are at just the right distance from the sun
4. we have the right stuff to host a dynamic core
5. we have a big moon to stabilize our axial wobble
6. we have an ozone layer to block harmful ray

Question 3

the presence of planet Jupiter, farther out in the solar system blocking Earth from much of the incoming debris

Answer 3

our location is far from many hazards

Question 4

the solar system sits far from the galactic core (almost 30,000 light-years), between two major spiral arms

Answer 4

our location is far from many hazards

Question 5

• the sun is a yellow dwarf, a relatively rare type of star that is both small and stable
• it also has a long life and probably would not start to fizzle out for another five billion years or more

Answer 5

our sun is a stable and long-lasting star

Question 6

earth is at an average distance of 93 million miles or 150 million kilometers away from the sun

Answer 6

we are just at the right distance from the sun

Question 7

zone where the planet receives enough energy to allow water to exist as a liquid on its surface

Answer 7

goldilocks zone

Question 8

• the Earth’s magnetic field serves to deflect most of the solar wind, whose charged particles would otherwise strip away the ozone layer that protects the Earth
• keeps the planet’s atmosphere in place and helps humans and animals to find their way around

Answer 8

we have the right stuff to host a dynamic core

Question 9

moon’s stabilizing effect on our orbit, our climate is a lot steadier

Answer 9

we have a big moon to stabilize our axial wobble

Question 10

what will happen if the moon is near the earth?

Answer 10

it would exert a greater gravitational force that would cause huge tides which could overflow onto the lowlands, causing great flooding

Question 11

ozone (O3) is a gas in the atmosphere that protects everything living on the Earth from harmful ultraviolet (UV) rays from the sun

Answer 11

we have an ozone layer to block harmful ray

Question 12

mixture of gases found in the atmosphere

Answer 12

• nitrogen 78% (atmosphere)
• oxygen 21% (greenhouse gas)
• argon 0.9% (greenhouse gas)