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The Universe
Name: ____________
Our Sun:
 93 000 000 miles away
 made up of mostly Hydrogen and Helium that burns at millions of
degrees (10 000 degrees F) and powered by nuclear fusion
 considered a yellow dwarf
 can fit 1 000 000 Earths in it
 largest (only) star in our solar system (1 000 000 miles across)
 a source of heat & energy (takes 8 seconds to travel from the Sun to
Earth
 Created 5 billion of years ago in a massive explosion called a
supernova (a larger older star exploded) and collected together to
form our solar system by gravity
 The largest stellar body in our solar system with the strongest gravity
pull, that’s why all our planets revolve around it
 Earth is the perfect distance away from the Sun, if we were any
closer, our oceans would boil away and our surface would be hot
enough to melt lead; if we were farther out, our planet would be a
frozen wasteland
 Sunspots are dark areas on the sun that are up to 1000 degrees
cooler than the area around them
 Like the Earth, the sun rotates. But it is not a solid, so it does not
rotate evenly; the axis changes.
 Earth rotates on its axis as a solid, creating its own gravitational pull
and two poles
The Inner, Rocky, Planets
Mercury
 Closest planet to the Sun
 No moons
 Extremely low level of gravity
o No atmosphere (no protection from asteroids, meteoroids)
o 150 lbs on Earth = 57 lbs on Mercury
o No interior source of heat
 Smallest planet (60% smaller than Earth)
 One Mercury day = 180 Earth days (longest day?)
 One Mercury year = 88 Earth days (fastest planet)
 One year is shorter than one day on Mercury
 Peculiar weather
o For 6 months the side facing the Sun reaches 800ºF, while the
other side (away from the Sun) temperature drops to -300ºF
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o Takes a long time to heat up and a long time to cool down
o The sky would look black because of a lack of atmosphere
Surface: tons of impact craters (causes many seismic shock waves),
volcanic craters, rough, jumbled terrain, rock and lots of dust
Has ice in the craters located at both the North and South Poles
(permanently shaded craters protected from the Sun)
Venus
 2nd planet from the Sun
o Earth’s twin – about the same size
o Also known as the morning or evening star
o Closest planet to Earth
 Named after the Roman goddess of Love & Beauty
 One Venus (Venusian) year = 225 Earth days
 One Venus day = 8 Earth months
 Lower level of gravity than Earth, 150 lbs on Earth = 136 lbs on Venus
 Has a very slow, reversed rotation (believed to be a result of having
been hit by a meteor)
o The Sun rises in the west and sets in the east
 Wicked climate
o At 900ºF, Venus is the hottest planet (a human unprotected
by a space suit would cook to death in a second or two)
o The extreme heat is caused by, the “Green House Effect”.
Lots of Green House Gases: carbon dioxide (95%)and
nitrogen trap the heat causing the planet to heat up.
o The many volcanoes are responsible for the CO2
o Lots of lightening in the sky (it doesn’t hit the ground) because
of the thick clouds
o Sulphuric acid rain
o Little sunlight due to the thick cloud cover (80% of light
bounces off the clouds)
 Surface: volcanoes, molten rock, gases, sulphur, sharp volcanic rock
(70% of the surface), craters
Maxwell Mons, highest volcano on Mars (higher than any mountains on
Earth)
Earth
Mars, The Red Planet
 Named after the Roman God of War for its blood red colour
 1/2 the size of Earth
 Potential base for future colonization?
 Evidence of life in the past – microbes, water
 Iron oxide (rust) gives Mars its red colour
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Cold (-100 degrees F), dry, lots of sand, huge dust storms, no
oxygen, the atmosphere is made up almost entirely of carbon
dioxide
Tallest known mountain in the solar system – Olympus Mons – an old
volcano
Like Earth, has two icy polar caps
Many craters from meteorites (not much of an atmosphere-no
protection)
The Asteroid Belt
Is a ring of rocks and debris that circles the Sun between Mars and Jupiter.
The Gas Giants and Outer Planets
Jupiter, The Giant Planet
 Largest planet in the solar system, visible to the naked eye
 A great churning ball of gas, 84% Hydrogen and almost 28% Helium
 Can fit 1000 Earths inside Jupiter
 A day on Jupiter is 9.9 Earth hours long
 Orbits the Sun in 11.86 Earth years
 150 lbs on Earth = 350 lbs on Jupiter
 Thunder clouds made of ammonia, sulphur and water
 No solid surface
 Perhaps it is a failed star, all the right ingredients but not enough
mass?
 Perhaps a garbage collector - comets, meteoroids are attracted to
Jupiter because of its gravity, saving Earth?
 Giant Red Spot is the eye of an enormous (12 000 miles across-Earth
is 8000 miles wide) storm that has been raging for at least 300 years.
Composed of wild lightening and 350 mile/hr winds.
 Has several dozen moons, but has 4 more well known moons: Io
(volcanic); Ganymede (largest in the solar system); Calisto
(cratered), and Europa (icy)
 Jupiter’s moon, Europa, is suspected to have liquid water – life?
May have warm thermal vents under the water. Water = the
possibility of life.
Saturn, Lord of the Rings
 6th planet from the Sun, 2nd largest planet in our solar system
 Named after Kronos by the Greeks (Saturnus by the Romans) god of
the Harvest
 750x larger than Earth
 One Saturn day = 10.6 Earth hours
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One Saturn year = 29.5 Earth years
Has 48 named moons
Has a rocky core surrounded by gas - no surface
Very cold, made of Hydrogen and Helium
Spins rapidly, so it is not round but kind of flat at the poles
Low gravity compared with Earth
Less dense than water, so Saturn would float on water
Surrounded by seven wide, thin rings composed of chunks of ice,
ranging in size from cars to powder
o The inner rings spin faster than the outer rings
o First discovered by Galileo
o We can see the rings of Saturn because they reflect the Sun’s
light
Could be called the weather planet
o Lots of violent storms that can last days or months
o Winds blow at 1000 kms/hr
o Lots of lightening
o Has a huge hurricane-type storm on the South Pole
o Has a hexagon shaped North Pole
Titan, Saturn’s largest moon
o 2nd largest moon in the solar system (the size of Mercury)
o Has rocks, craters and dunes
o Seems to have some kind of “goo” on the surface that is
neither liquid nor solid.
o Has an atmosphere made of nitrogen and methane – very
similar to what we think Earth used to have before it had
‘Life’
o Has no liquid water and is very cold, -300 degrees F
o Has liquid methane, a source of fuel
Enceladus, Saturn’s smallest moon
o Has eruptions occurring on its southern surface
o Surface is formed of rock, ice and snow
o Thought to have water present
Uranus, the Sideways Planet
 7th planet in our solar system
 Named after the Greek God of the sky
 Uranus’ axis is tilted on its side, 42 years of winter, 42 years of summer
 One Uranus year = 84 Earth years
 One Uranus Day = 17.2 Earth hours
 Lower level of gravity than Earth, 150 lbs on Earth = 133 lbs on Uranus
 Its bluish green colour comes from large concentrations of
methane. Methane absorbs red and orange colours from sunlight
but reflects blue and green
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It has a hazy, smoggy atmosphere. Made up of gas and dust; there
is no solid surface
Heavy atmosphere would crush you because of the pressure
Thought to have a rocky core but no interior heating system
Discovered by Hershel and the first telescope
Has 5 thin rings composed of rocky dust
Uranus 27 known moons that have unruly orbits. They are expected
to collide at some point
Neptune, The Blue-Green Planet
 8th planet in our solar system
 Named after the Roman God of the Seas
 One Neptune year = 165 Earth years
 One Neptune day = 16.1 Earth hours
 Higher level of gravity than Earth, 150 lbs on Earth = 169lbs on
Neptune
 Neptune spins rapidly and is known to have violent winds (+1000
kms/hr)
 30x farther from the Sun than Earth, so dim light
 Neptune thought to have a lot of radio activity happening inside
releasing large amounts of heat and causing lots of violent weather
and varied cloud patterns
 Clouds are thought to be made up of methane
 Had a great dark spot in its Southern Hemisphere, thought to have
been a large storm or cyclone that disappeared after 5 years, now
it has one in the Northern Hemisphere
 Neptune as 13 known moons
 Triton, Neptune’s largest moon
o Roughly the size of our moon
o Coldest place in our solar system (-399 degrees F)
o Has eruptions like Saturn’s moon, Enceladus. Eruptions spew
out a mixture of liquid nitrogen, methane and ammonia
which freezes and then falls back to the surface of the planet
like snow
o Thought to have water present
 Also has thin rings
Pluto, Dwarf Planet
 Once considered to be the 9th planet
 Named for the Roman God of the Under World
 Very small in relation to the planets
 Has an oval shaped orbit
 One Pluto year = 248 Earth years
 One Pluto Day = 6.4 Earth days
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Very low gravity, 150 lbs on Earth = 10 lbs on Pluto
Pluto is made up of three types of ice: carbon monoxide, methane,
nitrogen and rock
30-40x further from the Sun than Earth, very dim and very cold (-388
degrees F)
Pluto probably has lots of craters from impact of asteroids or
meteoroids. There is no wind or water, no rain or erosion happening
to change the surface
Because of Pluto’s weird orbit, it comes close to the Sun at times.
This causes some of its ice to melt creating a temporary atmosphere
before the gases eventually freeze again (as Pluto moves away
from the Sun), falling back to the surface
No longer considered to be a planet after the discovery of Eris and
a new definition of a planet was made that excluded Pluto and Eris.
o New definition of a Planet: A planet is a spherical object,
that orbits the Sun and clears out the neighbourhood around
its orbital path
Pluto is now considered to be a dwarf planet and part of the Kuiper
Belt, a ring surrounding our solar system formed of small icy bodies
o Pluto, Eris and Ceres are all considered to be dwarf planets
o Ceres was once considered to be an asteroid found in the
asteroid belt found between Mars and Jupiter