The Planet Saturn

Information about the planet Saturn

Most frequently required information

Saturn Diameter: 120,536 km, 9.4 Earth Diameters
Saturn's Mass: 5.68x1026 kg, 94.3 Earth masses
Average Distance from Sun: 1.427 billion km, 9.53 AU (astronomical units)
Length of Day: 10 hours 40 minutes
Length of Year: 29.46 Earth Years
How many moons does Saturn have? 30
Planetary ring system: Yes
Average temperature: ~134 K (-139 C)
Atmospheric composition: Mostly hydrogen and helium.

AU stands for astronomical unit.
One AU is the average distance from the center of the Earth to the center of the Sun: 149,597,870 km


Mass (1024 kg) 568.46
Volume (1010 km3) 82,713
Radius (1 bar level) (km)
Equatorial 60,268
Polar 54,364
Volumetric mean radius (km) 58,232
Ellipticity (Flattening) 0.09796
Mean density (kg/m3) 687
Gravity (eq., 1 bar) (m/s2) 8.96
Escape velocity (km/s) 35.5
Number of natural satellites 30 Facts about Saturn's moons
Planetary ring system Yes
Saturn Orbital parameters
Semimajor axis (106 km) 1,433.53
Sidereal orbit period (days) 10,759.22
Tropical orbit period (days) 10,746.94
Perihelion (106 km) 1,352.55
Aphelion (106 km) 1,514.50
Synodic period (days) 378.09
Orbit inclination (deg) 2.485
Orbit eccentricity 0.0565
Sidereal rotation period (hours) 10.656 (Saturnian System III coordinates)
Length of day (hrs) 10.656
Obliquity to orbit (deg) 26.73

Semimajor axis (106 km) Mean distance from the Sun (or other central body in the
case of satellites) from center to center in 10^6 kilometers
Sidereal orbit period (days) The time it takes the body to make one revolution about
the Sun relative to the fixed stars in days.
Synodic period (days) The time interval between similar configurations in the
orbit (e.g. opposition) of the body and Earth, in days.
Perihelion (106 km) The point in a body's orbit closest to the
Sun, in 10^6 kilometers.
Aphelion (106 km) The point in a body's orbit furthest from
the Sun, in 10^6 kilometers.
Orbit inclination (deg) The inclination of the orbit to the ecliptic, in degrees.
For satellites, this is with respect to the planet's
Orbit eccentricity A measure of the circularity of the orbit, equal to
(aphelion - perihelion distance)/(2 x semi-major axis)
For a circular orbit, eccentricity = 0.
Sidereal rotation period (hrs) The time for one rotation of the body on its axis
relative to the fixed stars, in hours. A minus sign
indicates retrograde rotation.
Length of day (hrs) 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, on Earth this defines a 24 hour day.
Obliquity to orbit (deg) The tilt of the body's equator relative to the body's
orbital plane, in degrees.

Saturn Observational Parameters

Discoverer: Unknown
Discovery Date: Prehistoric

Distance from Earth
Minimum (106 km) 1195.5
Maximum (106 km) 1658.5
Apparent diameter from Earth
Maximum (seconds of arc) 20.1
Minimum (seconds of arc) 14.5
Mean values at opposition from Earth
Distance from Earth (106 km) 1277.42
Apparent diameter (seconds of arc) 19.5
Apparent visual magnitude 0.7
Maximum apparent visual magnitude 0.43
Saturnian Atmosphere
Surface Pressure: >>1000 bars
Temperature at 1 bar: ~134 K (-139 C)
Temperature at 0.1 bar: ~84 K (-189 C)
Density at 1 bar: ~0.19 kg/m3
Wind speeds
Up to ~400 m/s (<30 degrees latitude)
Up to ~150 m/s (>30 degrees latitude)
Scale height: 59.5 km
Mean molecular weight: 2.07 g/mole
Atmospheric composition (by volume, uncertainty in parentheses)
Major: Molecular hydrogen (H2) - 96.3% (2.4%); Helium (He) - 3.25% (2.4%)
Minor (ppm): Methane (CH4) - 4500 (2000); Ammonia (NH3) - 125 (75);
Hydrogen Deuteride (HD) - 110 (58); Ethane (C2H6) - 7 (1.5)
Aerosols: Ammonia ice, water ice, ammonia hydrosulfide

Moon Phases

Les phases de la Lune
The Moon - Quiz number 1
Moon phases - Quiz number 1
The Moon's phases - Quiz number 2

Selected beautiful pictures of the moon
Pictures of lunar domes, catena and rills

Photographic map of the Moon - 28 web pages
Photographic map of the Moon - 40 photographs

Set 1: Picture quizzes about named features on the moon
Set 2: Picture quizzes about named features on the moon

The current phase of the moon, monthly and yearly calenders

Stereoscopic 3D (3 dimensional) image pairs of the Moon

25 Solar System and other astronomy posters

Interactive jigsaw puzzle of the full moon
Interactive slider puzzle of the full moon
Memory game of a map of the moon

Related Planets

» Mercury
» Venus
» Earth
» Mars
» Jupiter
» Saturn
» Uranus
» Neptune
» Pluto

Why is the sky blue ?

Blue sky: short explanation
Blue light gets scattered (spread) around much more than all the other colors from the sun, causing the sky to appear blue.
Blue sky: a more detailed explanation
Light is made up of electromagnetic waves.

The distance between 2 crests in this wave is called the wavelength.

White light contains all the colors of the rainbow.

The amount of light scattered for any given colour depends on the wavelength of that colour.

All the colors in white light have different wavelengths.

Red light has the longest wavelength.

The wavelength of blue light is about half that of red light.

This difference in wavelength causes blue light to be scattered nearly ten times more than red light. Lord Rayleigh studied this phenomena in detail. It is caused the Tyndall effect or Rayleigh scattering.

Lord Rayleigh also calculated that even without smoke and dust in the atmosphere, the oxygen and nitrogen molecules would still cause the sky to appear blue because of scattering.

When blue light waves try to go straight through an oxygen and nitrogen molecules, its light is scattered in all directions because of this collision.

This scattered blue light is what makes the sky blue.

All other colors (with longer wavelengths than blue light) are scattered too.

Blue light's short wavelength causes it to be scattered the most.

(The shorther the wavelength of the color, the more that color gets scattered by the atmosphere)

Actually, violet has the shortest wavelength of all colors. Violet is scattered even more than blue light. However, our eyes are much more sensitive to see blue than violet, therefore we see the sky as blue.

Very little visible light is absorbed by the atmosphere.

Blue sky: summary
Blue light's short wavelength causes it to get scattered around 10 times more by oxygen and nitrogen molecules than the longer wavelengths (like red) of the other colors visible to us.

The blue in the sky we see is scattered blue light.

Take these short online quizzes to test your understanding of this blue sky explanation

Why the Sky is Blue, a Poem by John Ciardi
I don't suppose you happen to know
Why the sky is blue? It's because the snow
Takes out the white. That leaves it clean
For the trees and grass to take out the green.
Then pears and bananas start to mellow,
And bit by bit they take out the yellow.
The sunsets, of course, take out the red
And pour it into the ocean bed
Or behind the mountains in the west.
You take all that out and the rest
Couldn't be anything else but blue.
Look for yourself. You can see it's true.

About this website

This website has one goal:

To be of educational value (mainly for middle school students).
About me

This website was developed and designed by Alwyn Botha.

You can reach me at

I stay at Plot 42, Hartbeespoort, South Africa.

Telephone: +27 72 370 8491

Photo of me

About you

Please report any mistakes using this form - thank you.

Your comments and suggestions are welcome - send it to me

Thank you.

Alwyn Botha

Who to thank

Thanks to everyone at NASA and elsewhere that made these pictures of the planet Saturn available.