The Solar System

The Solar System

• Our tiny corner of Universe is dominated by a star we call the Sun.

• Trapped in the gravity of the Sun is a huge family of bodies – planets, moons, asteroids, comets which hurtle with it through space.

• This family is our Solar System.

• The effects of the Sun, its heat, gravity and light extend far beyond the farthest planet, Pluto, to about a quarter of the way to the next nearest star, Proxima Centauri.

The Planets

• Nine planets orbit the Sun at different distances.

• The four inner planets (Mercury, Venus, Earth and Mars) are balls of rock and metal.

• The outer planets (Jupiter, Saturn, Uranus and Neptune) are giant balls of gas and liquid. Pluto, the furthest planet is made from ice and rock.

• The time it takes a planet to orbit the Sun is its orbital period (its year). Planets also rotate as they travel. The time it takes for a planet to rotate once is its rotation period (its day).

The Sun• Size: Diameter of 1,390,000 km• Mass: 1.99 x 1030 kg• Distance from Earth: 149.6 million km• Composition: 70% Hydrogen, 28% Helium,

2% other elements• Temperature: Surface: 5,800oC

Core: 15,600,000oC• Planets: 9• Colour: Orange

• The Sun is a 1.4 million km ball of burning gas.

• Variations in the Sun’s magnetic field cause huge solar flares to shoot into space.

• Solar flares can be accompanied by dense clouds of electrically charged solar wind.

• Solar wind can disrupt communication satellites.

The Sun

Mercury• Size: Diameter of 4,880 km• Mass: 3.30 x 1023 kg• Distance from Sun: 57.91 million km• Distance from Earth: Max 207.9 million km

Min 92 million km• Atmosphere: Negligible atmosphere• Temperature: 450oC Day; -170oC Night • Length of Year: 88 Earth days• Length of Day: 59 Earth days• Moons: None• Colour: Dark Grey• Core: Iron rich core about 3600 km in diameter

• The most conspicuous feature on the planet is the huge Caloris Basin (1300 km across).

• The Caloris Basin was formed by a collision between Mercury and another rocky body.

• Mercury has the widest temperature range on any planet in the Solar System.

Mercury

Venus• Size: Diameter of 12,104 km• Mass: 4.87 x 1024 kg• Distance from Sun: 108.21 million km• Distance from Earth: Max 258 million km

Min 41 million km• Atmosphere: Mainly carbon dioxide

90 times Earth pressure• Temperature: Average 480oC• Length of Year: 225 Earth days• Length of Day: 243 Earth days• Moons: None• Colour: White cloud tops• Core: Iron/Nickel core

• Venus has the longest day of any planet in the Solar System (243 days).

• It’s the only planet where the sun rises in the west and sets in the east.

• Venus has a poisonous atmosphere – it is full of sulphuric acid.

• It’s thick carbon dioxide atmosphere creates a strong greenhouse effect.

Venus

Earth• Size: Diameter of 12,756 km• Mass: 5.97 x 1024 kg• Distance from Sun: 149.6 million km• Atmosphere: Mainly nitrogen with oxygen and

carbon dioxide• Temperature: Average 22oC• Length of Year: 365.26 Earth days• Length of Day: 24 Earth hours• Moons: 1 (The Moon)• Colour: Blue and green• Core: Iron/Nickel core

• The only planet in the Solar System where life has been confirmed.

• The planet is the correct distance from the Sun for water to exist as a liquid.

• Earth’s oceans help regulate the planet’s temperature.

• The Earth’s atmosphere and magnetic field shield the planet from most of the solar radiation.

Earth

Mars• Size: Diameter of 6,792 km• Mass: 6.42 x 1023 kg• Distance from Sun: 228 million km• Distance from Earth: Max 378 million km

Min 78 million km• Atmosphere: Thin carbon dioxide atmosphere• Temperature: Average -55oC • Length of Year: 687 Earth days• Length of Day: 24 Earth hours 37 minutes• Moons: 2 (Deimos and Phobos) • Colour: Red• Core: Small iron core

• The temperature of Mars is closer to Earth than any other planet in the Solar System (27oC in summer).

• Valles Marineres is the longest ever canyon system. It measures over 5,000 km along the equator with an average depth of 6 km.

• Olympus Mons is the largest volcano in the Solar System. It measures 700 km wide and reaches 27 km high.

Mars

Jupiter• Size: Diameter of 142,984 km• Mass: 1.90 x 1027 kg• Distance from Sun: 778.3 million km• Distance from Earth: Max 928 million km

Min 628 million km• Atmosphere: Mainly hydrogen and helium• Temperature: -123oC at the surface

20,000oC at the core• Length of Year: 4,333 Earth days• Length of Day: 10 Earth hours 40 minutes• Moons: 58+ (Io, Europa, Ganymede and Callisto)• Colour: Yellow/orange• Core: Rocky iron core

• Jupiter is one of the four ‘gas giant’ planets. It is composed of a swirling ball of gas with a small rocky core.

• The Great Red Spot is a vast thunderstorm that has raged on Jupiter for over 400 years.

• The Great Red Spot is over twice the size of Earth and is the largest thunderstorm in the Solar System.

Jupiter

• Size: Diameter of 120,536 km• Mass: 5.68 x 1026 kg• Distance from Sun: 1,429.4 million km• Distance from Earth: Max 1,579 million km

Min 1,279 million km• Atmosphere: Mainly hydrogen and helium• Temperature: -180oC at the surface

12,000oC at the core• Length of Year: 10,750 Earth days• Length of Day: 10 Earth hours 14 minutes• Moons: 31+ (Titan, Iapetus, Dione, Encelaus, Mimas)• Colour: Beige• Core: Rocky iron core

Saturn

• Saturn is a ‘gas giant’, like its larger neighbour Jupiter.

• Saturn ring system is the most spectacular in all the Solar System.

• These rings are made up of billions of rock particles ranging from a few microns to a few meters in length.

• The planet’s density is so small that it could float on water.

Saturn

Uranus• Size: Diameter of 51,118 km• Mass: 8.68 x 1025 kg• Distance from Sun: 2,875 million km• Distance from Earth: Max 3,025 million km

Min 2,725 million km• Atmosphere: Hydrogen, helium, methane• Temperature: -214oC • Length of Year: 30,707 Earth days• Length of Day: 17 Earth hours 12 minutes• Moons: 21+ (Oberon, Titania, Umbriel, Ariel, Miranda)• Colour: Blue/green• Core: Rocky ice core

• Like Jupiter, Saturn & Neptune Uranus is a planet made almost entirely of hydrogen, helium and methane gas.

• Uranus appears blue due to its atmospheric methane that absorbs red light from the Sun.

• Uranus is a featureless planet. Enhanced imaging shows seasonal atmospheric changes

• Uranus is the only planet to spin on its side.

Uranus

Neptune• Size: Diameter of 49,532 km• Mass: 1.02 x 1026 kg• Distance from Sun: 4,504 million km• Distance from Earth: Max 4,564 million km

Min 4,354 million km• Atmosphere: Hydrogen, helium and methane• Temperature: -220oC• Length of Year: 60,202 Earth days• Length of Day: 16 Earth hours 7 minutes• Moons: 11+ (Triton)• Colour: Deep blue• Core: Rocky ice core

• Neptune is one of the four ‘gas giant’ planets, composed almost entirely of gas.

• Voyager 2 spotted a small white cloud shooting around Neptune’s upper atmosphere every 16 hours.

• Neptune has the wildest weather in the Solar System, with winds of up to 2,000 km/h

• During certain points in its orbit Neptune becomes the furthest planet from the sun.

Neptune

Pluto• Size: Diameter of 2,300 km• Mass: 1.27 x 1022 kg• Distance from Sun: 5,915 million km• Distance from Earth: Max 7,525 million km

Min 4,275 million km• Atmosphere: Thin nitrogen atmosphere with

carbon dioxide and methane• Temperature: -223oC • Length of Year: 90,803 Earth days• Length of Day: 6.39 Earth days• Moons: 1 (Charon)• Colour: Unknown• Core: Unknown

• Pluto is the furthest planet from the Sun, except for a 20 year period in its 248 year orbit when it comes closer to the Sun than Neptune.

• Hubble telescope images show light and dark regions

• Lighter areas are probably ices of nitrogen, methane, ethane and carbon dioxide.

• Darker areas may be a result of chemical reactions driven by cosmic rays.

Pluto

Asteroids• Asteroids are lumps of

rocky debris that float around in the Solar System.

• Most are found in the asteroid belt between Jupiter and Mars.

• They range in size from tiny dust particles to nearly 1,000 km across.

• Class C: silicates Class M: nickel + iron Class S: nickel + iron +

silicates

• Comets are icy chunks of water and dust that originate in the outer Solar System.

• When comets approach the Sun they vapourise, hence developing a bright tail.

• Comets originate from two regions, the Kuiper Belt and the Oort Cloud.

• The Kuiper Belt extends from Neptune out past Pluto.

• The Oort Cloud surrounds the entire Solar System.

Comets