1. Surveying The Solar System Poking Around the Neighbourhood

2. What’s Out There? What are the celestial bodies? How far away are they? What does the earth have in common with them? How is the Earth different?

3. We’ve gotten a few answers… Hubble Space Probes –Venera –Solar Observer –Pioneer –Viking –Voyager –Pathfinder (Mars) –Apollo (manned)

4. The Sun 1.4 Million km in diameter –1,400,00 km –1.4 x 10 6 km Composed mostly of hydrogen Surface constantly churns and writhes Some areas are cooler - appear darker –Known as sun spots Violent outbursts called solar flares erupt regularly Flares make solar wind

7. Sun Statistics Mass (kg)1.989e+30 Mass (Earth = 1)332,830 Equatorial radius (km)695,000 km Equatorial radius (Earth = 1)108.97 Mean density (gm/cm^3)1.410 Rotational period (days)25-36* Escape velocity (km/sec)618.02 Mean surface temperature6,000°C Corona Temperature1,000,000 °C Internal Temp15 000 000 °C Age (billion years)4.5

8. Principal chemistry Hydrogen 92.1% Helium 7.8% Oxygen 0.061% Carbon 0.030% Nitrogen 0.0084% NeonIron 0.0076% Silicon 0.0037% Magnesium 0.0031% Sulfur 0.0024% All others 0.0015%

9. The Planets There are 9 planets in our solar system All are quite different from each other Inner 4 are rocky (M, V, E, M) Outer 4 are gas giants (J, S, U, N) Last on - Pluto - just plain weird (P) M y V accuum E xploded M om it J ust S ucks U p N othing - P oop!

11. Scale - using the Earth as 1 Earth –Diameter -> 12750 km ( 1 ED) –Distance From the Sun -> 149 599 000 km = 1 AU Venus –Diameter -> 12000 km (0.95 ED) 12000 / 12750 Inside the SS we use Astronomical Units Outside the SS we use light years