Exploring our Solar System

Question 1

Order of planets in the solar system.

Answer 1

1. Mercury
2. Venus
3. Earth
4. Mars
5. Jupiter
6. Saturn
7. Uranus
8. Neptune
9. Pluto

Question 2

What type of orbits do comets have?

Answer 2

Comets have very elliptical orbits: they pass inside the orbit of mercury and go well beyond the orbit of Pluto.

Question 3

What are meteors made of and what do they do?

Answer 3

• A meteor is made from grains of dust that burn up as they pass through the Earth’s atmosphere.
• They heat the air around them which glows and the streak is known as a ‘shooting star’.

Question 4

Black Holes

Answer 4

• Are formed where large stars used to be.
• You cannot see a black hole because light cannot escape from it.
• It has a very large mass but a small size.

Question 5

Why do the moons orbit planets and planets orbit stars?

Answer 5

• Centripetal forces act on them:
  
  • Centripetal force acts towards the centre of the circular orbit.
  • Gravitational attraction is the source of the centripetal force.

Question 6

What are the advantages of unmanned probes?

Answer 6

• Unmanned probes can go where conditions are deadly for humans.
• An unmanned spacecraft in space costs less than an astronaut.
• They do not put astronauts lives at risk.

Question 7

A spacecraft

Answer 7

• Carrying humans has to have a large amount of food, water and oxygen aboard.
• Allows astronauts to wear normal clothes because the spacecraft is pressurised.

Question 8

When travelling in space…

Answer 8

Astronauts are subjected to a lower gravitational field than on earth.

Question 9

Outside the spacecraft they need to wear specialised suits:

Answer 9

• A dark visor stops an astronaut being blinded
• The suit is pressurized and has an oxygen supply for breathing.
• The surface of the suit facing towards sun can reach 120°C
• The surface of the suit facing away from the sun can be as cold as -160 °C

Question 10

What is the speed of light?

Answer 10

300,000 km/s

Question 11

Light from the:

Answer 11

• Sun takes about eight minutes to reach us on Earth
• Next nearest star (Proxima Centauri) takes 4.22 years

Question 12

What is America planning to do?

Answer 12

America plans a manned mission to mars after 2020 at a cost of £400 billion.