**Mercury**

Mass: 0.3302 x 10^{24} kg

Volume: 6.083 x 10^{10} km^{3}

Average radius: 2439.7 km

Average diameter: 4879.4 km

Mean density: 5.427 g/cm^{3}

Escape velocity: 4.3 km/s

Surface gravity: 3.7 m/s^{2}

Visual magnitude: -0.42

Natural satellites: 0

Rings? – No

Semimajor axis: 57,910,000 km

Orbit period: 87.969 days

Perihelion: 46,000,000 km

Aphelion: 69,820,000 km

Mean orbital velocity: 47.87 km/s

Maximum orbital velocity: 58.98 km/s

Minimum orbital velocity: 38.86 km/s

Orbit inclination: 7.00°

Orbit eccentricity: 0.2056

Sidereal rotation period: 1407.6 hours

Length of day: 4222.6 hours

Discovery: Known since prehistoric times

Minimum distance from Earth: 77,300,000 km

Maximum distance from Earth: 221,900,000 km

Maximum apparent diameter from Earth: 13 arc seconds

Minimum apparent diameter from Earth: 4.5 arc seconds

Maximum visual magnitude: -1.9

**Venus**

Mass: 4.8685 x 10^{24} kg

Volume: 92.843 x 10^{10} km^{3}

Average radius: 6051.8 km

Average diameter: 12103.6 km

Mean density: 5.243 g/cm^{3}

Escape velocity: 10.36 km/s

Surface gravity: 8.87 m/s^{2}

Visual magnitude: -4.40

Natural satellites: 0

Rings? – No

Semimajor axis: 108,210,000 km

Orbit period: 224.701 days

Perihelion: 107,480,000 km

Aphelion: 108,940,000 km

Mean orbital velocity: 35.02 km/s

Maximum orbital velocity: 35.26 km/s

Minimum orbital velocity: 34.79 km/s

Orbit inclination: 3.39°

Orbit eccentricity: 0.0067

Sidereal rotation period: 5832.5 hours

Length of day: 2802.0 hours

Discovery: Known since prehistoric times

Minimum distance from Earth: 38,200,000 km

Maximum distance from Earth: 261,000,000 km

Maximum apparent diameter from Earth: 66.0 arc seconds

Minimum apparent diameter from Earth: 9.7 arc seconds

Maximum visual magnitude: -4.6

**Earth**

Mass: 5.9736 x 10^{24} kg

Volume: 108.321 x 10^{10} km^{3}

Average radius: 6,371.0 km

Average diameter: 12,742 km

Mean density: 5.515 g/cm^{3}

Escape velocity: 11.186 km/s

Surface gravity: 9.798 m/s^{2}

Visual magnitude: -3.86

Natural satellites: 1

Rings? – No

Semimajor axis: 149,600,000 km

Orbit period: 365.256 days

Perihelion: 147,090,000 km

Aphelion: 152,100,000 km

Mean orbital velocity: 29.78 km/s

Maximum orbital velocity: 30.29 km/s

Minimum orbital velocity: 29.29 km/s

Orbit inclination: 0.00°

Orbit eccentricity: 0.0167

Sidereal rotation period: 23.9345 hours

Length of day: 24.0000 hours

Axial tilt: 23.45°

**Mars**

Mass: 0.64185 x 10^{24} kg

Volume: 16.318 x 10^{10} km^{3}

Average radius: 3,389.5 km

Average diameter: 6,779 km

Mean density: 3.933 g/cm^{3}

Escape velocity: 5.03 km/s

Surface gravity: 3.71 m/s^{2}

Visual magnitude: -1.52

Natural satellites: 2

Rings? – No

Semimajor axis: 227,920,000 km

Orbit period: 686.980 days

Perihelion: 206,620,000 km

Aphelion: 249,230,000 km

Mean orbital velocity: 24.13 km/s

Orbit inclination: 1.850°

Orbit eccentricity: 0.0935

Sidereal rotation period: 24.6229 hours

Length of day: 24.6597 hours

Axial tilt: 25.19 °

Discovery: Known since prehistoric times

Minimum distance from Earth: 55,700,000 km

Maximum distance from Earth: 401,300,000 km

Maximum apparent diameter from Earth: 25.1 arc seconds

Minimum apparent diameter from Earth: 3.5 arc seconds

Maximum visual magnitude: -2.91

**Jupiter**

Mass: 1,898.6 x 10^{24} kg

Volume: 143,128 x 10^{10} km^{3}

Average radius: 69,911 km

Average diameter: 139,822 km

Mean density: 1.326 g/cm^{3}

Escape velocity: 59.5 km/s

Surface gravity: 24.79 m/s^{2}

Natural satellites: 63

Rings? – Yes

Semimajor axis: 778,570,000 km

Orbit period: 4,332.589 days

Perihelion: 740,520,000 km

Aphelion: 816,620,000 km

Mean orbital velocity: 13.07 km/s

Orbit inclination: 1.304°

Orbit eccentricity: 0.0489

Sidereal rotation period: 9.9250 hours

Length of day: 9.9259 hours

Axial tilt: 3.13°

Discovery: Known since prehistoric times

Minimum distance from Earth: 588,500,000 km

Maximum distance from Earth: 968,100,000 km

Maximum apparent diameter from Earth: 50.1 arc seconds

Minimum apparent diameter from Earth: 29.8 arc seconds

Maximum visual magnitude: -2.94

**Saturn**

Mass: 568.46 x 10^{24} kg

Volume: 82,713 x 10^{10} km^{3}

Average radius: 58,232 km

Average diameter: 116,464 km

Mean density: 0.687 g/cm^{3}

Escape velocity: 35.5 km/s

Surface gravity: 10.44 m/s^{2}

Natural satellites: 60

Rings? – Yes

Semimajor axis: 1,433,530,000 km

Orbit period: 10,759.22 days

Perihelion: 1,352,550,000 km

Aphelion: 1,514,500,000 km

Mean orbital velocity: 9.69 km/s

Orbit inclination: 2.485°

Orbit eccentricity: 0.0565

Sidereal rotation period: 10.656 hours

Length of day: 10.656 hours

Axial tilt: 26.73°

Discovery: Known since prehistoric times

Minimum distance from Earth: 1,195,500,000 km

Maximum distance from Earth: 1,658,500,000 km

Maximum apparent diameter from Earth: 20.1 arc seconds

Minimum apparent diameter from Earth: 14.5 arc seconds

Maximum visual magnitude: 0.43

**Uranus**

Mass: 86.832 x 10^{24} kg

Volume: 6,833 x 10^{10} km^{3}

Average radius: 25,362 km

Average diameter: 50,724 km

Mean density: 1.270 g/cm^{3}

Escape velocity: 21.3 km/s

Surface gravity: 8.87 m/s^{2}

Natural satellites: 27

Rings? – Yes

Semimajor axis: 2,872,460,000 km

Orbit period: 30,685.4 days

Perihelion: 2,741,300,000 km

Aphelion: 3,003,620,000 km

Mean orbital velocity: 6.81 km/s

Orbit inclination: 0.772°

Orbit eccentricity: 0.0457

Sidereal rotation period: 17.24 hours

Length of day: 17.24 hours

Axial tilt: 97.77°

Discovery: 13 March 1781

Minimum distance from Earth: 2,581,900,000 km

Maximum distance from Earth: 3,157,300,000 km

Maximum apparent diameter from Earth: 4.1 arc seconds

Minimum apparent diameter from Earth: 3.3 arc seconds

Maximum visual magnitude: 5.32

**Neptune**

Mass: 102.43 x 10^{24} kg

Volume: 6,254 x 10^{10} km^{3}

Average radius: 24,622 km

Average diameter: 49,244 km

Mean density: 1.638 g/cm^{3}

Escape velocity: 23.5 km/s

Surface gravity: 11.15 m/s^{2}

Natural satellites: 13

Rings? – Yes

Semimajor axis: 4,495,060,000 km

Orbit period: 60,189 days

Perihelion: 4,444,450,000 km

Aphelion: 4,545,670,000 km

Mean orbital velocity: 5.43 km/s

Orbit inclination: 1.769°

Orbit eccentricity: 0.0113

Sidereal rotation period: 16.11 hours

Length of day: 16.11 hours

Axial tilt: 28.32°

Discovery: 23 September 1846

Minimum distance from Earth: 4,305,900,000 km

Maximum distance from Earth: 4,687,300,000 km

Maximum apparent diameter from Earth: 2.4 arc seconds

Minimum apparent diameter from Earth: 2.2 arc seconds

Maximum visual magnitude: 7.78

We’ve written many articles about the Solar System. Here’s an article about how many moons there are in the Solar System, and here’s an article about the formation of the Solar System.

If you’d like more info on the Solar System, check out NASA’s Planetary Fact Sheet.

We’ve recorded several episodes of Astronomy Cast about the Solar System. Start here, Episode 49: Mercury.