Chap 12

Question 1

How is the distance between the planets n the sun determined

Answer 1

• astronomical unit and light years are used to measure the relative distances between the planets and the sun

Question 2

explain astronomical unit (A.U.)

Answer 2

• is the average distance between the earth and the sun ( which is approx 93 million miles or 150 million km)
• 1 A.U. = 1.5 x 10^8 km

Question 3

explain light years (ly)

Answer 3

• refers to the distance travelled by light in one year
• light moves at a velocity of 300 000 km every second
• 1 light year = 9.5 x 10^12km

Question 4

What r the planets in solar system (in order)

Answer 4

-mercury
-venus
-earth
-mars
-jupiter
-saturn
-uranus
-neptune

Question 5

Explain about mercury

Answer 5

• the closest planet to the sun , approx 57.9 mil km
  -it is the smallest planet in the solar system
  -smaller than jupiter’s moon , Ganymede ‘ and saturn’s moon, titan
• surface is similar to the surface of the moon, w asteroid craters n cliffs which r tens of km high
• Sky appears dark in outer space bcuz light cannot be scattered in the absence of atmosphere

Question 6

Explain Venus

Answer 6

• second closest planet to the sun
• known as the greenhouse planet bcuz of the high content of carbon dioxide in its atmosphere
  -also rotates from east to west, which differs from other planets which rotate west to east, this causes the sun to rise from the west on venus
• the size n age of venus is the same as the earth, but its climate is far more challenging , w a temp of approx 460 C

Question 7

Explain about the earth

Answer 7

-third planet frm sun
- only place in the universe that is inhabited by living things
- has a layer of air known as the atmosphere , which protects the surface of the earth from solar wind, harmful ultraviolet rays and radiation from outer space
-more than 71% of the earth is covered in water n 29% land

Question 8

Explains about mars

Answer 8

• the fourth planet from the sun n is also known as the “red planet”
• has two moons , phobos n demos
• has a surface area that is only 25% that of the earth n its mass is 10% that of the earth
• if observed from earth, the atmosphere of mars can be divided into 2 diff areas
• the brighter area is covered in dust n reddish sand, while the poles contain frozen water n carbon dioxide

Question 9

Explain about jupiter

Answer 9

• fifth planet frm the sun
  -largest planet
• mass is almost 320 times that of earth, twice the amount of all the planets in the solar system
• said to be the protector of the earth, able to deflect huge objects from hitting earth w its strong gravity

Question 10

Explain about saturn

Answer 10

• sixth planet frm the sun n the 2nd largest planet
• classified as a giant gas planet
• has a ring system which mostly comprises of ice w a small amount of rocky material n dust
• 62 moons hv been found to orbit this planet

Question 11

Explain about uranus

Answer 11

• seventh planet frm the sun n third biggest planet
• first elements in the interior of uranus r ice n rock
• astronomers often refer to it as a giant gas planet
• has a ring system similar to saturn, but its thinner n darker
• has many moons
• is unique bcuz its axis of rotation is tilted, almost parallel to its orbit and the sun
• takes 84 years (time of earth) to orbit the sun

Question 12

explain neptune

Answer 12

• eighth planet from the sun
• classified as a giant gas planet
• takes almost 165 years (time on earth) to orbit the sun

Question 13

Explain the relationship between temp of a planet that do not hv an atmosphere n the sun

Answer 13

Mercury: -surface will cause the area that faces the sun to be extremely hot, more than 427 C
- darker area is extremely cold, temp can drop to -173 C

Question 14

Explain the relationship between temp of a planet that hv an atmosphere n the sun

Answer 14

Earth: - has clouds that reflect sunlight back into outer space but the atmosphere traps some of the heat, which causes greenhouse effect
Venus: has thick clouds that can reflect sunlight back into outer space, but the atmospheric layers consist carbon dioxide which cause greenhouse effect. More heat is trapped n surface temp can reach up to 462C
Mars: surface pressure of atmosphere is extremely low compared to that of earth, causing minimal effect on the surface temp
the surface temp fluctuates between -143C to 35 C

Question 15

Explain the relationship between temp of giant planets n the sun

Answer 15

Jupiter, Saturn, Uranus, Neptune:
- surface if these planets covered in gas
- receive very little sunlight
-surface temp r extremely low

Question 16

the gravity on the surface of a planet depends on

Answer 16

its mass and density

Question 17

the gravity of earth is

Answer 17

9.8 ms-2

Question 18

give a few facts about gravity in our solar system

Answer 18

• gravity of mercury n mars is lower than earth bcuz their masses r lower than earth
  -gravity of venus is almost the same as earth bcuz its mass is almost the same as earth’s mass
  -gravity of jupiter is much higher compared to earth bcuz its mass is extremely high although it has a low density
• although saturn, uranus n neptune hv very high mass, their gravity is not as high as the gravity of earth bcuz these giant gas planets hv low density.

Question 19

The further a planet is from the sun, :

Answer 19

the more time it needs to orbit the sun

Question 20

Explain abt the rotational direction of planets

Answer 20

• all planets rotate on their axis at diff angles
  -all planets rotate from west too east except venus n uranus
  -venus rotates from east to west while uranus rotates on its side

Question 21

What happens if the rotation of the earth slows down or stops completely?

Answer 21

• longer day and night duration in 2 diff parts of the earth
• change in high and low tides
• temp will drop in areas of the earth that do not receive sunlight
• more desert areas in parts of the earth that faces the sun

Question 22

whats natural satelites

Answer 22

• objects that move around planets on their own orbit
  -moon is the only natural satellite of the earth

Question 23

why would the moon be facing the earth at all times

Answer 23

• this is bcuz the moon also moves around the earth on its orbit, and the duration taken is also the same – 27 days.

Question 24

What r the few factors that allows earth to support life

Answer 24

-presence of water
-minerals
-temperature
-atmospheric content

Question 25

state the characteristics of earth

Answer 25

• has alot of water for all living processes
• has high oxygen content for respiratory process
• has a suitable temp range, not too hot or cold
• its atmosphere blocks harmful ultraviolet rays from reaching the earth
  -receives sunlight for plants to conduct photosynthesis
• has gravity that keeps object from floating

Question 26

meaning of ecological footprint

Answer 26

-the measure of the ability of water n land to provide the basic needs of humans aswell as the ability of the earth to absorb all human wastes n reproduce resources after they have been used by humans.

Question 27

ecological footprint is the ratio measurement for six areas, which are

Answer 27

• carbon dioxide waste treatment areas
• construction areas
  -forests
  -agricultural areas
• farming areas
  -fishing areas

Question 28

if the ecological footprint exceeds the ability of the earth to renew its resources,

Answer 28

the earth will be depleted of all its resources

Question 29

ecological footprint is different between

Answer 29

countries

Question 30

Why isnt mercury the hottest planet in the solar system

Answer 30

• mercury has very weak atmosphere so it cannot hold anything