(See notes following tables.)
| planet or object | type | average distance from Sun (Earth=1) | orbital period (d)ays or (y)ears | diameter (Earth=1) | average surface temperature Celsius | structure | atmosphere | surface | known moons |
|---|---|---|---|---|---|---|---|---|---|
| (Sun) | star | -- | -- | 109 | 5600° (sunspots 3500°) | H and He plasma, fusion reactions in core, corona and solar wind above surface | 13 planets and dwarf planets, 777,015 asteroids, 2,716 TNOs, 6,339 comets | ||
| Mercury | terrestrial | 0.4 | 90 d | 0.38 | 180° (430° to -170°) | rock, metal core | none | craters | none |
| Venus | terrestrial | 0.7 | 220 d | 0.95 | 460° | rock, metal core | thick, CO2, some N2 | plains, volcanic features, covered by clouds | none |
| Earth | terrestrial | 1.0 | 1.0 y | 1.0 | 10° (40° to -20°) | rock, metal core | N2, O2 | water oceans, varied geologic activity on land, life | 1 large |
| Mars | terrestrial | 1.5 | 1.9 y | 0.53 | -45° (-100° to 0°) | rock, metal core | thin, CO2, some N2 | craters, plains, volcanoes, canyons, polar caps | 2 small |
| Jupiter | jovian | 5 | 12 y | 12 | -120° (cloudtops) | mostly liquid metallic hydrogen, atmosphere, rock core | thick, H2, He | cloudtops: cloud bands, circular storms | 79 (4 large, 75 small); faint rings |
| Saturn | jovian | 10 | 30 y | 9 | -155° (cloudtops) | liquid hydrogen, atmosphere, rock/ice core | thick, H2, He | cloudtops: cloud bands, haze | 62 (1 large, 6 medium, 55 small); rings |
| Uranus | jovian | 19 | 80 y | 4 | -200° (cloudtops) | atmosphere, ice, rock core | thick, H2, He, CH4 | cloudtops: clouds, haze | 27 (5 medium, 22 small); narrow rings |
| Neptune | jovian | 30 | 160 y | 4 | -205° (cloudtops) | atmosphere, ice, rock core | thick, H2, He, CH4 | cloudtops: cloud bands, storms | 14 (1 large, 13 small); narrow rings |
Note: In 2006 the International Astronomical Union reclassified Pluto as a dwarf planet instead of a planet. Some astronomers still recognize Pluto as a planet.
| object | type | average distance from Sun (Earth=1) | orbital period (y)ears | diameter (Earth=1) | average surface temperature Celsius | structure | atmosphere | surface | known moons |
|---|---|---|---|---|---|---|---|---|---|
| Ceres | asteroid | 2.8 | 4.6 y | 0.07 | -110° | rock and ice | none | craters, salt deposits | none |
| Orcus* | TNO | 39 (range 30-48) | 250 y | 0.07 | -230° | various ices, rock core? | none? | various ices? | 1 medium |
| Pluto | TNO | 40 (range 30-50) | 250 y | 0.19 | -240° | various ices, rock core | thin, N2, CH4, CO | ice plains, craters, water ice mountains, nitrogen glaciers, methane deposits | 5 (1 medium, 4 small) |
| (307261) 2002 MS4* | TNO | 42 (range 36-48) | 270 y | 0.07 | -230° | various ices, rock core? | none? | various ices? | none |
| Salacia* | TNO | 42 (range 37-47) | 270 y | 0.07 | -230° | various ices, rock core? | none? | various ices? | 1 small |
| Haumea | TNO | 43 (range 35-52) | 280 y | 0.13 | -240° | various ices, rock core | ? | various ices? | 2 (1 medium, 1 small); rings |
| Quaoar* | TNO | 44 | 290 y | 0.08 | -230° | various ices, rock core? | none? | various ices? | 1 small |
| Makemake | TNO | 46 (range 38-53) | 310 y | 0.11 | -245° | various ices, rock core | ? | various ices? | 1 small |
| (225088) 2007 OR10* | TNO | 67 (range 33-101) | 550 y | 0.12 | -225° to -245° | various ices, rock core? | ? | various ices? | 1 small |
| Eris | TNO | 68 (range 38-97) | 560 y | 0.18 | -260° | various ices, rock core | ? | various ices? | 1 medium |
| Sedna* | TNO | 480 (range 76-880) | 10,500 y | 0.08 | -245° to -265° | various ices, rock core? | none? | various ices? | none |
Note: Only Pluto, Eris, Haumea, Makemake, and Ceres are officially designated dwarf planets. Of many candidate dwarf planets, the largest are listed here and designated with *.
| moon | primary planet | average distance from center of planet | orbital period (d)ays | diameter (Earth=1) | average surface temperature Celsius | structure | atmosphere | surface |
|---|---|---|---|---|---|---|---|---|
| Moon | Earth | 380,000 km | 27 d | 0.27 | 100° to -170° | rock/metal | none | craters, lava plains |
| Io | Jupiter | 400,000 km | 2 d | 0.28 | 0° to -190° | rock, metal core | none | volcanoes, volcanic runoff |
| Europa | Jupiter | 700,000 km | 4 d | 0.25 | -150° to -190° | rock/metal, ice crust over a water ocean | none | ice, frozen fractures |
| Ganymede | Jupiter | 1,100,000 km | 7 d | 0.41 | -130° to -190° | ice, rock core | none | dirty ice plains, craters, ridges |
| Callisto | Jupiter | 1,900,000 km | 17 d | 0.38 | -130° to -190° | rock, ice | none | craters, ice and dirt |
| Titan | Saturn | 1,200,000 km | 16 d | 0.40 | -140° to -190° | rock, ices | N2, CH4 | various ices, methane seas, covered by haze |
| Triton | Neptune | 350,000 km | 6 d | 0.18 | -230° | rock, ices | thin, N2, CH4 | plains of various ices, craters, geysers |
These tables are intentionally simplified to give a quick overview of planetary characteristics--you should not prefer this data over more precise or up-to-date data from other sources. More data, and more precise data, are available from many sources such as the National Space Science Data Center at http://nssdc.gsfc.nasa.gov/planetary/. Date of this data: July 2018.
The jovian planets do not have accessible surfaces, so information at their cloudtops is substituted for "surface" data. The Earth-Sun average distance is 150,000,000 kilometers (km); Earth's diameter is 12,700 km. "TNO" is trans-Neptunian object, which refers to large icy asteroid-like objects beyond Neptune. "Ice" refers to water ice, "ices" may include other ices: nitrogen, methane, ammonia. For size of moons, "large" refers to those over 2,000 km diameter and "medium" to those between 350 and 2,000 km in diameter. In addition to the 198 known moons of planets and dwarf planets, there are 276 known moons of asteroids and 80 known moons of trans-Neptunian objects.
The chemical symbols used are for methane (CH4), carbon monoxide (CO), carbon dioxide (CO2), hydrogen (H), molecular hydrogen (H2), helium (He), nitrogen (N2), oxygen (O2).
Last modified 30 January 2019.
Return to Home. Return to Other Information Resources.