Today: Placing the Universe in Context: Sizes & Scales

It’s All Relative & Units Matter Earth is BIG Home Base - Earth

Earth is BIG

Radius = 6378 km (3963 mi)

3rd Planet from the Sun Earth is BIG Home Base - Earth

Earth is Massive

Mass = 6x1024 kilograms (kg)

3rd Planet from the Sun The Solar System is BIGGER Earth is part of the Solar System

• One star (the Sun) Mercury • Eight Major Planets Venus • 4 (or more?) Dwarf Planets Earth • 166+ moons Mars • Asteroids Jupiter • Comets Saturn • A lot of Dust Uranus We are here Neptune The Solar System is BIGGER Earth is part of the Solar System

Mercury • Terrestrial Planets: Mercury, Venus, Earth, Mars Venus • Jovian Planets: Jupiter, Saturn, Uranus, Neptune Earth Mars • Mass of Jupiter = 318x Earth Jupiter Saturn Uranus We are here Neptune

318 Earth masses The Universe is BIG Observable Universe Local Universe Virgo Supercluster Local Group The Milky Way Local Stellar Neighborhood Sun & Solar System Earth 0.1 light-seconds around (25,000 miles)

1.3 light-seconds

8 light-minutes (1 Astronomical Unit) The Universe is BIG Observable Universe Pluto: 5 light-hours Local Universe Virgo Supercluster Local Group The Milky Way Local Stellar Neighborhood Sun & Solar System Nearest Star: 4 light-years Earth

Orion: 1,500 light-years

Center of the Milky Way: 26,000 light-years The Universe is BIG Andromeda Galaxy: Observable Universe 2.5 Million light-years Local Universe Virgo Supercluster Local Group Virgo Supercluster: The Milky Way Local Stellar Neighborhood 100 Million light-years Sun & Solar System Earth

Local Universe: 1 Billion light-years

Observable Universe: 93 Billion light-years ??