All the Planets of the Solar System - The basic facts / information

This is a table showing some facts on all the planets of our Solar System - and also the Moon.
The table lists planets in order of their distance from the Sun.
We are using the official list of 8 planets and 5 dwarf planets as defined by the International Astronomical Union (IAU).

Table of Planet Information

	Mercury	Venus	Earth	Luna	Mars	Jupiter	Saturn	Uranus	Neptune
Mass (10²⁴kg)	0.330	4.87	5.97	0.073	0.642	1898	568	86.8	102
Diameter (km)	4879	12,104	12,756	3475	6792	142,984	120,536	51,118	49,528
Density (kg/m³)	5427	5243	5514	3340	3933	1326	687	1271	1638
Gravity (m/s²)	3.7	8.9	9.8	1.6	3.7	23.1	9.0	8.7	11.0
Escape Velocity (km/s)	4.3	10.4	11.2	2.4	5.0	59.5	35.5	21.3	23.5
Rotation Period (hours)	1407.6	-5832.5	23.9	655.7	24.6	9.9	10.7	-17.2	16.1
Length of Day (hours)	4222.6	2802.0	24.0	708.7	24.7	9.9	10.7	17.2	16.1
Orbit Average (10⁶ km)	57.9	108.2	149.6	0.384	227.9	778.6	1433.5	2872.5	4495.1
Orbit Closest (10⁶ km)	46.0	107.5	147.1	0.363	206.6	740.5	1352.6	2741.3	4444.5
Orbit Furthest (10⁶ km)	69.8	108.9	152.1	0.406	249.2	816.6	1514.5	3003.6	4545.7
Orbital Period (days)	87.9	224.7	365.2	27.3	687.0	4332	10,759	30,688	60,182
Orbital Period (Years)	0.24	0.61	1.00	0.07	1.88	11.86	29.45	84.02	164.77
Average Orbital Velocity (km/s)	47.4	35.0	29.8	1.0	24.1	13.1	9.7	6.8	5.4
Orbital Inclination (degrees)	7.0	3.4	0.0	5.1	1.9	1.3	2.5	0.8	1.8
Orbital Eccentricity	0.205	0.007	0.017	0.055	0.094	0.049	0.057	0.046	0.009
Axial Tilt (degrees)	0.01	177.4*	23.4	6.7	25.2	3.1	26.7	97.8	28.3
Mean Temperature (C)	167	464	15	-20	-65	-110	-140	-195	-200
Surface Pressure (bars)	0	92	1	0	0.01	Unknown*	Unknown*	Unknown*	Unknown*
Number of Moons	0	0	1	0	2	79	82	27	14
Ring System?	No	No	No	No	No	Yes	Yes	Yes	Yes
Global Magnetic Field?	Yes	No	Yes	No	No	Yes	Yes	Yes	Yes
	Mercury	Venus	Earth	Luna	Mars	Jupiter	Saturn	Uranus	Neptune

And below is a table showing facts for each of the official Dwarf Planets.
The table lists the dwarf planets in order of their distance from the Sun.

Table of Dwarf Planet Information

	Ceres	Pluto	Haumea	Makemake	Eris
Mass (10²⁴kg)	0.009	0.013	0.004	?	.017
Diameter (km)	946	2374	1960 x 1518 x 996	1430 - 1478	1163
Density (kg/m³)	2161	1860	2600	1400 - 3200	2520
Gravity (m/s²)	0.28	0.62	0.063	?	0.82
Escape Velocity (km/s)	0.51	1.21	0.91	?	1.38
Rotation Period (hours)	9	-153	3.9	7.7	25.9
Length of Day (hours)	9	153	3.9	7.7	25.9
Orbit Average (10⁶ km)	413.6	5906.4	6432.0	6783.3	10,180
Orbit Closest (10⁶ km)	382.6	4436.7	5157.6	5671.9	5723
Orbit Furthest (10⁶ km)	445.4	7376.1	7706.4	7894.7	14,602
Orbital Period (days)	1681.6	90,560	103,774	112,897	203,830
Orbital Period (years)	4.60	248	284	309	558
Average Orbital Velocity (km/s)	17.9	4.7	4.5	4.4	3.43
Orbital Inclination (degrees)	10.59	17.14	28.19	29.0	44.0
Orbital Eccentricity	0.075	0.249	0.191	0.164	0.440
Axial Tilt (degrees)	4	119	?	?	?
Mean Temperature (C)	-105	-229	<-220	<-230	<-230
Surface Pressure (bars)	0	0	0	0	?
Number of Moons	0	5	2	0	1
Ring System?	No	No	No	No	No
Global Magnetic Field?	?	?	?	?	?
	Ceres	Pluto	Haumea	Makemake	Eris

Key to Table Information

Diameter - The diameter of the planet at the equator.

Gravity - The gravitational acceleration on the surface at the equator including the effects of rotation. For the gas giant planets the gravity is given at the 1 bar pressure level in the atmosphere.

Escape Velocity - Initial velocity, in kilometers per second or miles per second, needed at the surface (at the 1 bar pressure level for the gas giants) to escape the body's gravitational pull, ignoring atmospheric drag.

Rotation Period - This is the time it takes for the planet to complete one rotation relative to the fixed background stars (not relative to the Sun) in hours. Negative numbers indicate retrograde (backwards relative to the Earth) rotation.

Length of Day - The average time in hours for the Sun to move from the noon position in the sky at a point on the equator back to the same position.

Orbital Period - This is the time in Earth days for a planet to orbit the Sun (or for the Luna moon - to orbit the Earth) from one vernal equinox to the next. Also known as the tropical orbit period, this is equal to a year on Earth.

Orbital Inclination - The angle at which a planets orbit around the Sun is tilted relative to the ecliptic plane. The ecliptic plane is defined as the plane containing the Earth's orbit, so the Earth's inclination is 0.

Orbital Eccentricity - This is a measure of how far a planet's orbit about the Sun (or the Moon's orbit about the Earth) is from being circular. The larger the eccentricity, the more elongated is the orbit, an eccentricity of 0 means the orbit is a perfect circle.

Axial Tilt - The angle in degrees the axis of a planet (the imaginary line running through the center of the planet from the north to south poles) is tilted relative to a line perpendicular to the planet's orbit around the Sun.
*Venus rotates in a retrograde direction, opposite the other planets, so the tilt is almost 180 degrees, it is considered to be spinning with its "top", or north pole pointing "downward" (southward). Uranus rotates almost on its side relative to the orbit, Pluto is pointing slightly "down".

Mean Temperature - This is the average temperature over the whole planet's surface (or for the gas giants at the one bar level).

Surface Pressure - This is the atmospheric pressure (the weight of the atmosphere per unit area) at the surface of the planet.
*The surfaces of Jupiter, Saturn, Uranus, and Neptune are deep in the atmosphere and the location and pressures are not known.

Number of Moons - This gives the number of IAU officially confirmed moons orbiting the planet - although new moons are still being discovered all the time - so it's quite possible this table is out of date!

Ring System? - This tells whether a planet has a set of rings around it, Saturn being the most obvious example.

Global Magnetic Field? - This tells whether the planet has a measurable large-scale magnetic field. Mars and the Moon have localized regional magnetic fields but no global field.

Please Note: For some objects - especially the Dwarf planets, some of the statistics are derived from modelling and other non-direct measurements. This means that some figures shown are speculative and that there is a certain amount of error even on measured values. Also - putting this information together (from information published by NASA and wikipedia) has proven difficult in that different sources use different values without dates/explanations or reference. Therefore - we accept no responsibility in errors in the information given, either from the source or in compilation for this web page.

Answers to Common Questions About the Planets of our Solar System

Here are a list of common answers to questions about the solar system to save you looking through the data above:

Which Planet has the longest day?

If you consider a day to the time between mid day and the next mid day then Mercury easily has the longest day of 176 Earth days. However if you mean which planet spins slowest, the Venus wins with a rotation rate of once every 243 days. For a fuller explanation see our "Which planet has the longest day?" page.

Which planet is closest to the Sun?

Mercury is the closest planet to the Sun. Its orbit is very eccentric (e.g. non-circular) and Mercury comes to within 46 million km from the Sun at its closest point and 69.8 million km at its furthest point. More Info.

Which planet is furthest from the Sun?

Neptune is the furthest planet from the Sun. At the furthest point in its orbit, Neptune reaches 4.5 billion km from the Sun.

Which planet is the biggest?

Jupiter is the biggest planet in our solar system. It is three times heavier than the next heaviest planet, Saturn, and makes up 71% of the total mass of the planets of our solar system. Its diameter at 143,000 km is almost 20% bigger than Saturn’s, and it has a volume 67% larger than Saturn’s.

Which is the smallest planet?

Mercury is the smallest planet in our solar system. It is only 4.5 times heavier than the Earth's Moon, and has about half the mass of Mars, the next biggest planet. It's diameter and 4879 km is just under 4/10ths that of the Earth's.

What planets are bigger than the Earth?

The planets that are bigger than the Earth are the Gas Giants - Jupiter, Saturn, Uranus and Neptune. Earth is the biggest of the inner (rocky) planets, Venus being the next largest followed by Mars and then Mercury.

How many planets are there around the Sun?

There are 8 planets around the Sun. Listed in distance from the Sun they are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. There are also 5 dwarf planets around the Sun - Ceres, Pluto, Haumea, Makemake and Eris. To find out more, visit our "How many planets are there in the Solar System page".

Is Mars or Earth closer to the Sun?

Earth is closer to the Sun than Mars. Mars is about 50% further out from the Sun than the Earth is and so the sunshine on Mars is less than half as bright as on the Earth. With less light and a very thin atmosphere, Mars is colder than the Earth with an average temperature around -65 degrees C (Earth's average is 15 degrees C and rising).

Which planet is closest to the Earth?

Venus is the planet that comes closest to Earth. At the closest point in their orbits they can be only 38.2 million km apart. Earth's next closest neighbour is Mars which comes as close as 54.5 million km. However the distance between the planets is changing all the time as they move in their orbits. The distance between Venus and Earth can be as much as 261 million km when they are on opposite sides of the Sun from each other.

Why do planets orbit the Sun?

Planets orbit the Sun because they are continually falling toward the Sun but, because they also have a sideways velocity component (e.g. 90 degrees to the direct path to the Sun) they keep missing the Sun. And because in space there is virtually nothing to slow them down, they just keep on falling and missing and falling and missing... forever. Any planet that doesn't have enough sideways velocity to miss the Sun, will hit it and be destroyed. In other words we only see planets (and asteroids and comets, etc.) today since everything else crashed into the Sun millions of years ago. Indeed we still see comets that fall into the sun because they don't have enough sideways velocity to miss it.

Why do all planets orbit in the same plane?

It's thought that planets tend to orbit in the same plane because they were all formed in a huge spinning disk of gas and dust that was created as all the particles within a gas/dust cloud starting pulling together due to gravity. Rather like the water going down a plug hole, as the particles got closer to the center they started spinning and very quickly a single direction of spin became dominant, and the cloud flattened into a disk. As time went on particles in the disk clumped together and eventually created planets.