Planets - Data Table

Dwarf Planets are listed in a separate table below.

Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune
diameter (Earth=1) 0.382 0.949 1 0.532 11.209 9.44 4.007 3.883
diameter (km) 4,878 12,104 12,756 6,787 142,800 120,000 51,118 49,528
mass (Earth=1) 0.055 0.815 1 0.107 318 95 15 17
mean distance from Sun (AU) 0.39 0.72 1 1.52 5.20 9.54 19.18 30.06
orbital period (Earth years) 0.24 0.62 1 1.88 11.86 29.46 84.01 164.8
orbital eccentricity 0.2056 0.0068 0.0167 0.0934 0.0483 0.0560 0.0461 0.0097
mean orbital velocity (km/sec) 47.89 35.03 29.79 24.13 13.06 9.64 6.81 5.43
rotation period (in Earth days) 58.65 -243* 1 1.03 0.41 0.44 -0.72* 0.72
inclination of axis (degrees) 0.0 177.4 23.45 23.98 3.08 26.73 97.92 28.8
mean temperature at surface (C) -180 to 430 465 -89 to 58 -82 to 0 -150 -170 -200 -210
gravity at equator (Earth=1) 0.38 0.9 1 0.38 2.64 0.93 0.89 1.12
escape velocity (km/sec) 4.25 10.36 11.18 5.02 59.54 35.49 21.29 23.71
mean density (water=1) 5.43 5.25 5.52 3.93 1.33 0.71 1.24 1.67
atmospheric composition none CO2 N2 + O2 CO2 H2+He H2+He H2+He H2+He
number of moons
rings? no no no no yes yes yes yes

Dwarf Planets

Ceres Pluto Haumea Makemake Eris
diameter (Earth=1) 0.076 0.180 0.110
(average)
0.102-0.149 0.188-0.235
diameter (km) 974.6 2,300 1,960 x 1,518 x 996
(ellipsoid)
1,300-1,900 2,400-3,000
mass (Earth=1) 0.00016 0.002 0.00070 0.00067 0.0028
mean distance from Sun (AU) 2.76596 39.44 43.335 45.791 67.6681
orbital period (Earth years) 4.599 247.7 285.4 309.88 557
orbital eccentricity 0.07976 0.2482 0.18874 0.159 0.44177
mean orbital velocity (km/sec) 17.882 4.74 4.484 4.419 3.436
rotation period (in Earth days) 0.378 -6.38* 0.163 ? > 8 hrs ?
inclination of axis (degrees) 3 122 ? ? ?
mean temperature at surface (°C) -106 -220 -223 -240 -230
gravity at equator (Earth=1) 0.028 0.06 0.045 0.051 0.082
escape velocity (km/sec) 0.51 1.27 0.84 0.8 1.31
mean density (water=1) 2.077 2.03 2.6-3.3 2 1.18-2.31
atmospheric composition none CH4 none? maybe CH4 maybe CH4
number of moons
rings? no no no no no
* Negative values of rotation period indicate that the planet rotates in the direction opposite to that in which it orbits the Sun. This is called retrograde rotation.

The eccentricity (e) is a number which measures how elliptical orbits are. If e=0, the orbit is a circle. All the planets have eccentricities close to 0, so they must have orbits which are nearly circular.

Last modified October 9, 2008 by Randy Russell.

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Dwarf Planets

In 2006 the International Astronomical Union (IAU) approved a new classification scheme for planets and smaller objects in our Solar System. Their scheme includes three classes of objects: "small solar...more

Eccentricity of an Orbit

You may think that most objects in space that orbit something else move in circles, but that isn't the case. Although some objects follow circular orbits, most orbits are shaped more like "stretched...more

Carbon Dioxide - CO2

Carbon dioxide (CO2) is a kind of gas. There isn't that much carbon dioxide in Earth's atmosphere, but it is still very important. Carbon dioxide is a greenhouse gas. That means it helps trap heat coming...more

Nitrogen

There is more nitrogen gas in the air than any other kind of gas. About 4/5ths of Earth's atmosphere is nitrogen gas! A molecule of nitrogen gas is made up of two nitrogen atoms. There are other molecules...more

Oxygen

Oxygen (O2) is a kind of gas. A lot of the air you breathe is oxygen. That's a good thing, since we need oxygen to stay alive! About 4/5ths of the air in Earth's atmosphere is nitrogen (N2). Almost all...more

Pluto

Pluto is a frigid ball of ice and rock that orbits far from the Sun on the frozen fringes of our Solar System. Considered a planet, though a rather odd one, from its discovery in 1930 until 2006, it was...more

Makemake: a Dwarf Planet

Makemake is a dwarf planet in our Solar System. Makemake was discovered in March 2005 by a team of astronomers led by Mike Brown. Makemake officially became a dwarf planet in July 2008. There were three...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA