The Solar

System

The Structure of the Solar System

The Sun 4 Inner planets 4 Jovian planets 8 Dwarf planets

30 objects highly likely to be dwarf planets 60 objects which are likely to be dwarf planets 103 objects which are probably dwarf planets 394 objects which are possibly dwarf planets

The Sun

One of 100 billion stars in our galaxy The largest object in our solar system.

Contains >99.8% of the mass in our solar system

70% H, 28% He Energy produced by nuclear fusion

Mercury

Closest planet to the sun (0.4 AU), an inner planet

Terrestrial Named for Mercury, the

Roman messenger of the Gods

Similar in size to our moon (0.4x the size of Earth)

Iron-nickel core with silicate mantle

Mercury

Takes 59 days to spin on its axis

88 days to orbit the sun Gravity is 0.38x that of

Earth’s HOT days and COLD

nights (-183C – 427C) Atmosphere of sodium

and helium No moons known

Venus

Inner planet, 0.7 AU from sun Named for the Goddess of Love We can see it in the sky Similar to Earth’s mass and diameter Thick atmosphere of CO2, nitrogen

and sulphuric acid Very hot 480⁰C (runaway greenhouse

effect) Spins opposite of other planets,

takes 243 days to spin

Venus

One year = 224 Earth days

Gravity is 0.9x that of Earth’s

No known moons

Earth

Largest of the inner planets

Liquid water helps support life

Crust, mantle, liquid core, solid core Mantle consists of Mg, Fe,

SiO4

Core consists of Fe and Ni Not too hot, not too cold!

Earth

An inner planet, 1.0 AU from the sun Takes 23h, 56 min to spin on its axis Takes 365.25 days to orbit the sun Average temperature is 14C Atmosphere is 77% nitrogen, 21%

oxygen One moon – “the moon”

Mars

Named after the Roman god of war

Red in colour (iron oxide, Fe2O3) Atmosphere of Carbon Dioxide

(95.3%) and Argon 0.5 x Earth’s diameter 1.5 AU from the sun (inner

planet) A day on Mars is just a few

minutes longer than on Earth (24 hours, 37 min)

Mars

Olympus Mons – the largest volcano in the solar system (3x height of Mt. Everest)

Water on Mars (but not as much as Earth) Locked in permafrost in ice caps

2 moons: phobos and deimos

Average Temp: -63C Takes 687 days to orbit

the sun Gravity 0.38 of Earth’s

Asteroid Belt

Between Mars and Jupiter

Total mass would equal 10% of Earth’s moon

Ceres is the only dwarf planet in the inner solar system

Jupiter

Named after Roman king of the gods

5.2 AU from the Sun (outer planet)

Largest planet (11.2x the size of Earth)

Giant gas ball (atmosphere of H and He)

Solid core of Fe, rock, and H2O

Jupiter

66 moons discovered Huge storms – largest

storm is the Great Red Spot (so big, all of Earth could fit in it!)

Very faint rings Average temp: -130C Gravity: 2.64 x Earth’s 1 day = 9h, 55 min 1 year = 11.86 years

Saturn

Named after Roman god of agriculture

Large and beautiful ring system Ice with some rocky

material Atmosphere of H and He Lightest of all planets 62 moons discovered

Titan is a bit larger than Mercury

Saturn

9.6 AU from sun 9.5 x the size of Earth 1 day = 10 hours, 39

min 1 year = 29 years Gravity is 1.16x

Earth’s Average Temp: -130C

Uranus

Named after Greek god of the sky Coldest planet (-200C!) Blue-green colour ( Hydrogen, Helium and

Methane atmosphere) Tilted axis; spins on its side

One hemisphere almost all day, other almost all night

Uranus

27 known moons Outer planet, 19.2 AU from

sun 4x the size of Earth 1 day = 17h, 14min 1 year = 84 years Gravity = 1.11x Earth’s

Neptune

Named after Roman god of seas Smallest of gas planets (3.9x

Earth) Strong winds – up to 2000km/h Also has methane in atmosphere

causes green/blue colour Atmosphere is H, He, and

methane (CH4) Large storms – also has a ‘dark spot’ 13 moons (including Tritan)

Neptune

30.0 AU away from the sun (farthest ‘planet’) (outer planet)

1 day = 16h, 7 min 1 year = 164.8 years Gravity is 1.21x that on

Earth Cold! About -200C

Dwarf Planets (Including Pluto) A dwarf planet is a celestial

body that: Orbits the sun. Has enough mass to assume a

nearly round shape. Has not cleared the neighborhood

around its orbit. Is not a moon.

The first five recognized dwarf planets are Ceres, Pluto, Eris, Makemake and Haumea.

Dwarf Planets (Including Pluto) 8 Dwarf planets

30 objects highly likely to be dwarf planets 60 objects which are likely to be dwarf planets 103 objects which are probably dwarf planets 394 objects which are possibly dwarf planets