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 ??.