National Aeronautics and Space Administration Logo
Follow this link to skip to the main content NASA Banner
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

A solar system refers to a star and all the objects that travel in orbit around it. Our solar system consists of the sun - our star - eight planets and their natural satellites (such as our moon); dwarf planets; asteroids and comets. Our solar system is located in an outward spiral of the Milky Way galaxy.

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
Full Source List
Awards and Recognition   Solar System Exploration Roadmap   Contact Us   Site Map   Print This Page
NASA Official: Kristen Erickson
Advisory: Dr. James Green, Director of Planetary Science
Outreach Manager: Alice Wessen
Curator/Editor: Phil Davis
Science Writer: Autumn Burdick
Producer: Greg Baerg
Webmaster: David Martin
> NASA Science Mission Directorate
> Budgets, Strategic Plans and Accountability Reports
> Equal Employment Opportunity Data
   Posted Pursuant to the No Fear Act
> Information-Dissemination Policies and Inventories
> Freedom of Information Act
> Privacy Policy & Important Notices
> Inspector General Hotline
> Office of the Inspector General
> NASA Communications Policy
> USA.gov
> ExpectMore.gov
> NASA Advisory Council
> Open Government at NASA
Last Updated: 3 Aug 2014