1. Measuring the Universe
Big Numbers
At a rate of 200/minute
$200/min
200 km/min
200 years/min
How long will it take to reach:
1,000?
1 million (1,000,000)?
1 billion (1,000,000,000)?
1 trillion (1,000,000,000,000)?

2. 2. Distance Units in Astronomy
Astronomical Unit (AU) (pg 718 in Earth Sci text)
Average distance between Earth and the Sun
1 AU = 150 million km (90 million miles)
ex: Jupiter is 5.2 AU’s from the Sun
B) Light Year (LY)
The distance that light travels in a year
Speed of light = 300,000 km/sec (186,000 mile/sec)
LY = 9.5 trillion km (6 trillion miles)
C) Parsec = 3.26 LY’s

3. Travel Time Calculation
Time required = distance traveled / speed Example: Drive to New York City Distance = 2,892 miles Speed = 60 MPH Time = 2,892 mi / 60 mph = 48.2 hours Days? 48.2 / 24 = 2.0 days