Week 1

Question 1

Explain what retrograde means

Answer 1

outer planets have smaller orbits so the earth overtakes it and it makes the planets look like they’re going back and forth.

Question 2

How long is Mar’s retrograde cycle

Answer 2

Two years

Question 3

What do we call the earths orbit?

Answer 3

The Milankovitch cycle

Question 4

Name the three factors effecting the Earth’s orbit

Answer 4

Obliquity, Eccentricity and Procession

Question 5

What is the definition of Obliquity?

Answer 5

This is the tilt of the earth

Question 6

What is the earth’s current obliquity?

Answer 6

23.45 degrees

Question 7

How long is the obliquity cycle?

Answer 7

It ranges from 22.1 to 24.5 every 41,000 years

Question 8

What is the definition of eccentricity?

Answer 8

The distance to the sun, this is dictated by its position in its orbit

Question 9

What is the furthest point of the earth’s orbit to the sun called?

Answer 9

Aphelion

Question 10

What is the closest point of the earth’s orbit to the sun called?

Answer 10

Perihelion

Question 11

How long is the eccentricity cycle

Answer 11

100,000 years

Question 12

What is the definition of a procession?

Answer 12

The wobble of earth’s rotation

Question 13

How long is a procession cycle

Answer 13

26,000 years

Question 14

Explain what causes northern hemisphere ice growth

Answer 14

1. Low obliquity
2. Northern hemisphere summers in aphelion
3. High eccentricity

Question 15

Explain what causes northern hemisphere ice shrinkage

Answer 15

1. High obliquity
2. Northern hemisphere summers in perihelion
3. Low eccentricity

Question 16

How did the moon arise?

Answer 16

The collision of earth with a mars-like protoplanet, the outfall came together in orbit to become our moon

Question 17

How far away is the sun from earth?

Answer 17

1 Astronomical unit=1.49x10^8 km

Question 18

What is the earth’s tilt with the moon?

Answer 18

The moon helps stabilise the earth to 22.1 degrees

Question 19

What is the name of the furthest point of the moons orbit?

Answer 19

Apogee

Question 20

What is the closest point of the moon’s orbit?

Answer 20

perigee

Question 21

What is a spring tide and how are they formed?

Answer 21

This is an increased tide and is caused by the combine gravitational pull of the sun and moon as it aligns

Question 22

What is a neap tide and how do they form?

Answer 22

This is the decreased tide and is caused by the sun and moon being perpendicular from eachother.

Question 23

Umbra definition

Answer 23

The full shadow caused by an eclipse

Question 24

Penumbra

Answer 24

Partial shadow caused by an eclipse

Question 25

What is a solar eclipse?

Answer 25

When the moon passes between the earth and the sun causing a shadow and an eclipse of the sun

Question 26

What is a lunar eclipse?

Answer 26

When the moon is totally eclipsed by the shadow of the earth