• Tennis ball
• Clay - size of a peppercorn x2

• Clay - size of salt grains x2
• Clay - size of poppy seeds  x2
• Clay - size of a pea x1
• Clay - size of a grape x1
• Ruler - use to measure 1 AU
• 11 label tags of paper & a pen

INSTRUCTIONS:
Go outside into the corridor or stoep for this activity. 

Start at one end of corridor/stoep:

1. Put the Tennis ball on the ground: this represents the Sun.
2. Measure 10 cm (1/3 AU) away from the tennis ball and put a salt-grain sized piece of clay on the floor (on a paper tag). This represents Mercury. Label the tag "Mercury". 
3. Repeat this for each of the planets in your Solar System, using the photo inserted below as guide to distances between the planets. (Use appropriate sizes) 
4. Remember: 1AU = 1 Ruler length.
5. Take a photo of your Solar System and send it to your teacher, together with your answers to these questions:
6. Answer the questions below:

• Are the planets evenly spaced? 
• Is there some pattern you can find which fits what is seen? 
• Could you find some mathematical equation which would fit the pattern? 
• How does a planet's distance from the Sun relate to its temperature? 

• Optical telescopes (e.g SALT, Hubble)
• Radio telescopes (e.g. SKA)

• The Sun's surface often has dark spots on it, called sunspots. 
• They are areas that are cooler than the rest of the Sun's surface. 
• The Sun's surface is about 5500 °C.
• A typical sunspot's temperature is about 3900 °C.

• Planet—Celestial body that is in orbit around the Sun, has sufficient mass to assume a round shape, and has cleared the neighborhood around its orbit.

• Dwarf planet - A large, roughly spherical object orbiting a star, but that is not large enough to sweep out other objects from its orbit, e.g. Pluto.

• Asteroid: A small rocky object orbiting the Sun.

• Comet—Celestial object consisting of a nucleus of ice and dust and, when near the Sun, a “tail” of gas and dust particles pointing away. 

• Sun - A 3rd generation star around which the Earth and other planets orbits.

• Pulsar - A rotating neutron star that emits regular pulses of radio waves and other electromagnetic radiation.

• Constellation - A group of stars that form a pattern in the sky as viewed from Earth, e.g. Orion, Pavo the peacock, Phoenix, the Southern Cross.

• Galaxy - A collection of several 100 billion stars, gas and dust held together by gravity. E.g. the Milky Way galaxy (200 billion stars).

• Universe - A collection of 100 billion galaxies. 

• Light year- the distance that light travels in one year
  outwards from the Sun            = ±10 trillion km
• Light hour - the distance that light travels in one hour outwards from the Sun.

• Nuclear fusion: the process by which stars produce their energy; light atomic nuclei come together and merge to form heavier atomic nuclei, releasing energy as they do so; in the Sun, hydrogen nuclei fuse with other hydrogen nuclei to form heavier helium nuclei.
  
  
• Oort Cloud: a huge cloud of icy objects (comets) surrounding the Sun at the edge of the solar system. 

• Proxima Centauri: 2nd closest star after the Sun.
  
  
• Receiver: a device that detects radio wave signals.
  
  
• SALT: the Southern African Large Telescope, the largest optical telescope in the southern hemisphere.
  
  
• SKA: the Square Kilometer Array, the largest planned radio telescope array in the world.

• Solar wind: the continuous flow of charged particles from the Sun that extends out to the far reaches of the solar system.
  
  
• Spiral arm: a region of stars, gas and dust forming a curved shape spiraling out from the centre of a spiral galaxy.
  
  
• Star: a massive ball of burning gas which emits energy in the form of light and heat.

• Sunspot: a dark region or spot which appears on the surface of the Sun from time to time; sunspots are cooler than the rest of the Sun's surface.
  
  
• Telescope: an instrument used to look at distant objects, which makes distant objects appear brighter, larger and clearer. Some telescopes collect visible light (optical telescopes); others collect radio waves (radio telescopes).

• Kuiper Belt: region of space filled with trillions of small objects that lie in the outer reaches of the solar system, past the orbit of Neptune.
  
  
• Astronomical unit (AU): the average distance between the Earth and the Sun, equal to around 150 million kilometers.

• Decide on what equipment you will use to make your space station, spaceship or satellite.
• Design on paper before you start building.
• BUILD
• When you've finished, show off your finished creation to the class and answer questions regarding your project.

• Why did you choose to build this spacecraft?
• What does each part do?
• Do astronauts live in your creation? Where? 
• What would you do differently next time to improve your spacecraft?