1. Sizes and scales in Astronomy

2. 1mm

3. 1cm Earth: radius 6,400km equivalent to 0.5mm Jupiter 70,000km

4. Sun 700,000km Earth 6,400km Jupiter 70,000km

5. Distance from Earth to Sun is 149,600,000km = 1AU (12m) Sun EarthJupiter 1 AU 4 AU

6. Heliopause – 100 AU (1.2km) Pluto’s Orbit – 40 AU

7. 6km

8. 100km

9. 1500km

10. 3000km Solar System Proxima Centauri

11. 20,000km Stars Nearer than 5 pc: 70

12. Solar System 200 AU equivalent to 1mm (Earth is size of atom); 1 pc equivalent to 1m Rescale:

13. Stars within 5 pc

14. Milky way: 300,000pc across (300km)

15. Milky Way 30 galaxies, 10,000km across

16. Rescale: Milky Way 300,000pc equivalent to 10cm - Solar system smaller than size of atom - Earth 1,000 times smaller than the smallest sub-atomic particle known

17. Local Group Local Supercluster (Virgo, 2000 galaxies)

18. Observable Universe: 96,000,000,000pc across