1. How many light years away is Proxima Centauri if it is 2.5 x 10 13 miles away? Let’s start here: How many feet are in 3 miles? How many seconds are in 14.5 years? How many cm are in 6 inches? Back to Proxima Centauri… Light-Years

2. Warm-up 9/8-9 1. What makes a star a main sequence star? 2. Why does the size of the core of a main sequence star not change? 3. What will eventually happen to our Sun and why?

3. Scientific Notation Metric Conversion Unit Conversion Review

4. 32,000 0.00176 124,820 0.000004 8,000,000 0.0000001245 5.9228 0.00003987 16

5. 1.503 x 10 4 4.91 x 10 -2 9.5 x 10 12 2.3701 x 10 -8 5.9 x 10 12 7.354 x 10 0 6.900002 x 10 2 8.091 x 10 -12 4.02981 x 10 8

6. 921 m = ___ mm 140,000 mg = ___ cg 15 kL = ___ cL 3.2 cm = ___ km 16.48 hg = ___ g 150.2 kL = ___ mL 93,400 mm = ___ km 67.2 cg = ___ g 2 L = ___ mm

7. The diameter of the Milky Way is 100,000 light years. How many km is that? Mercury's average distance from the sun is 57,910,000 km. How many ly is that? The Earth is approximately 93,000,000 miles from the sun. How many ly is that?

8. Betelgeuse is 642.5 light years from Earth. How many km is that? How many miles is that? Gliese 581 c is a ‘super-Earth’ that is 1.9285 x 10 14 km away. How many light years is that? How many miles is that?