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Appendix E: YOU AND THE UNIVERSE
The distances between galaxies
Milky Way Galaxy Andromeda Galaxy (M31)
Whirlpool Galaxy (M51)
The Sun
2.2 million light-years 35 million light-years
The distance from the Earth to the Moon
The distances between the planets
The distance between stars
The distance from the Earth to the Sun is 93 million miles or 1 Astronomical Unit (AU)
Pluto’s elliptical orbitis eccentric and carriesthe planet
inside theorbit ofNeptune at itsclosest approachto theSun.
The distance from the Sun to the nearest star is about 4.3 light-years, or 25 trillion miles. This distance is so large that if a scale
model were created with the Earth one inch away from the Sun, the nearest star would have to be placed over 4 miles away!
Approximately one hundred billion stars, including the Sun, comprise the Milky Way Galaxy, which is a spiral-shaped
collection of stars believed to be more than 100,000 light years in diameter.
Radius = 239,000 miles
