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Bob the Alien's Tour of the Solar System
The Sun Mercury Venus Earth The Moon Mars Jupiter Saturn Uranus Neptune Pluto and Dwarf Planets Comets

Table of Planetary Statistics

Below is a table of statistics about the solar system's eight planets and five dwarf planets.

Regular Planets


Name of Planet Average Distance from Sun Diameter Time to Spin on Axis (a day) Time to Orbit Sun (a year) Gravity (Earth = 1) Average Temperature Contents of Atmosphere Year of Discovery Number of Known Moons
Mercury 57,900,000 km (36,000,000 miles) 4,878 km (3,031 miles) 59 days 88 days 0.38 -183 C to 427 C
(-297 F to 800 F)
Sodium, helium n/a None
Venus 108,160,000 km (67,000,000 miles) 12,104 km (7,521 miles) 243 days 224 days 0.9 480 C
(896 F)
Carbon Dioxide (96%), Nitrogen (3.5%) n/a None
Earth 149,600,000 km (92,960,000 miles) 12,756 km (7,926 miles) 23 hours, 56 mins 365.25 days 1 14 C
(57 F)
Nitrogen (77%), Oxygen (21%) n/a 1
Mars 227,936,640 km (141,700,000 miles) 6,794 km (4,222 miles) 24 hours, 37 mins 687 days 0.38 -63 C
(-81 F)
Carbon Dioxide(95.3%), Argon n/a 2
Jupiter 778,369,000 km (483,500,000 miles) 142,984 km (88,846 miles) 9 hours, 55 mins 11.86 years 2.64 -130 C
(-202 F)
Hydrogen, Helium n/a 66
Saturn 1,427,034,000 km (888,750,000 miles) 120,536 km (74,900 miles) 10 hours, 39 mins 29 years 1.16 -130 C
(-202 F)
Hydrogen, Helium n/a 62
Uranus 2,870,658,186 km (1,783,744,300 miles) 51,118 km (31,763 miles) 17 hours, 14 mins 84 years 1.11 -200 C
(-328 F)
Hydrogen, Helium, Methane 1781 27
Neptune 4,496,976,000 km (2,797,770,000 miles) 49,532 km (30,779 miles) 16 hours, 7 mins 164.8 years 1.21 -200 C
(-328 F)
Hydrogen, Helium, Methane 1846 13

Dwarf Planets


Name of Dwarf Planet Average Distance from Sun Diameter Time to Spin on Axis (a day) Time to Orbit Sun (a year) Average Temperature Year of Discovery Number of Known Moons
Ceres 413,900,000 km (257,031,000 miles) 950 km
(590 miles)
9 hours, 5 minutes 4 years, 220 days -106 C
(-159 F)
1801 None
Pluto 4,436,820,000 to
7,375,930,000 km (2,756,902,000 to 4,583,190,000 miles)
2,390 km
(1430 miles)
6 days, 9 hours 248 years -228 C
(-378 F)
n/a 5
Haumea 5,260,000,000 to
7,708,000,000 km (3,268,000,000 to 4,789,000,000 miles)
1960 x 1518 x 996 km
(1218 x 943 x 619 miles)
4 hours 285 years -240 C
(-400 F)
2004 2
Makemake 5,760,800,000 to
7.939,700,000 km (3,579,000,000 to 4,933,000,000 miles)
Between 1300 and 1900 km
(808 to
1180 miles)
7 hours, 46 minutes 309 years -243 C
(-405 F)
2005 None
Eris 5,665,500,000 to
14,634,000,000 km 3,518,000,000 to 9,088,000,000 miles
3,000 km (1,850 miles) 8 hours 557 years -248 to -232 C
-414 to -386 F
2005 1

Additional Information

DISTANCE FROM THE SUN:
The distance from the Sun given in the above table is the average distance the planet is away from the Sun. The planets don't orbit in completely circular orbits but in most cases, the difference between the planet's closest distance from the Sun doesn't vary greatly from its furthest point. Where the orbits are more elliptical than circular (where the planet's closest distance from the Sun varies greatly from its furthest point) the range is given.

DIAMETER:
The diameters of Jupiter and Saturn are wider across the equator (the values given in the table) than they are from their North to their South Poles. This is because of their fast rotational speeds which "squash" the planets. Dwarf Planet Haumea has an elongated shape so its dimensions rather than average diameter is given.

TIME TO SPIN ON AXIS:
This is the length of time it takes for the planet to complete one full rotation. This is measured in Earth time. For example, in the case of Mercury, it takes the planet 59 Earth days to spin on its axis.

TIME TO ORBIT SUN:
This is the length of time it takes for the planet to complete one full journey around the Sun. This is measured in Earth time. For example, in the case of Mars, it takes the planet 687 Earth days to orbit the Sun.

GRAVITY:
To work out your weight on another planet, multiply your weight by the number given in this column. Or use this handy calculator!

AVERAGE TEMPERATURE:
The average temperatures for the rocky Inner Planets (Mercury, Venus, Earth and Mars) and the Dwarf Planets (Ceres, Pluto and Eris) are the temperatures at the surface. The average temperatures for the Outer Planets (Jupiter, Saturn, Uranus and Neptune) are the temperatures at the tops of the planets' clouds. These gas planets will be hotter towards their - possibly solid - cores, generating their own heat sources, giving off more heat than they actually receive from the Sun.Where there is a large difference between the maximum and the minimum temperature on a planet, the full temperature range is given.

CONTENTS OF ATMOSPHERE:
Mercury is too small to actually possess a "sky-like" atmosphere. The gases listed in the table for Mercury are gases that surround the planets.

YEAR OF DISCOVERY:
The planets Mercury to Saturn were observed thousands of years ago and therefore don't have a date of discovery since there is nobody credited with being the first person to spot them. Uranus was the first planet to be discovered. It may possibly have been seen before its official date of discovery, but it would not have been recognised as a planet.

KNOWN MOONS:
Moons are constantly being discovered orbiting planets. The number of moons listed are the number confirmed when this page was updated (December 2012).