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Solar System Exploration
Planets
Planets
Sun Mercury Venus Earth Earth's Moon Mars Jupiter Saturn Uranus Neptune Dwarf Planets Dwarf Planets Dwarf Planets Comets Asteroids Meteroids Beyond Our Solar System Kuiper Belt Solar System
From our small world we have gazed upon the cosmic ocean for thousands of years. Ancient astronomers observed points of light that appeared to move among the stars.

Select a Solar System body to learn more.
Planet Selector Map

Our galaxy - the Milky Way - is a spiral galaxy with arms extending from the center like a pinwheel. Our solar system is in the Orion arm of the Milky Way. Our Sun is one of about 100 billion stars in the Milky Way. And our galaxy is just one of roughly 100 billion in the visible universe.

Eyes on the Solar System: Explore our galactic neighborhood in 3D!
Solar System Scoreboard
Scoreboard Box
Compare the Planets
Select a planet name from each column to compare their sizes.
Earth
Mars
  DIAMETER  
12742 km
6779 km
  RATIO  
1.88 km
1 km
Sources
USGS Astrogeology: Gazetteer of Planetary Nomenclature - Planetary Body Names and Discoverers
Solar System Dynamics - Planetary Satellite Discovery Circumstances
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Last Updated: 23 Jan 2013