An overview of the
Solar System
Our Solar System
The sun, and all the planets and
other bodies that travel around it.
Our solar system formed from a
nebula of dust and gas in a spiral arm
of the Milky Way Galaxy about 4.6
billion years ago
Solar System Formation
The sun and planets came
from a solar nebula (cloud of
gas and dust)
Gravity pulled most of the
matter inward and nuclear
fusion began forming the sun
(~99% of all the matter in the
nebula)
Small bodies called
planetesimals collided to form
protoplanets. The larger
protoplanets gravity collected
more matter until the planets
and moons formed.
Solar System Formation
The inner planets were to
small and close to the sun
and lost most of their
lighter gases (Hydrogen
and Helium) due to not
enough gravity and
radiation from the sun.
The outer planets were
far enough away to keep
their lighter gases.
Planet
A celestial body that orbits the sun, is
round because of its own gravity, and has
cleared the neighborhood around its
orbital path.
Planet Motion
Rotation: The spin of a body on its axis
Revolution: The motion of a body that
travels around another body in space; one
complete trip along an orbit.
The Sun
The sun is the
biggest, brightest, and
hottest object in the
solar system.
The sun is an
ordinary star creating
energy by nuclear
fusion.
The sun is made of
about 75% hydrogen
and 24% helium.
Mercury
Mercury has been known
since the ancients.
Mercury is the closest
planet to the sun
(.38 AU) and eighth
largest planet
(4,880 Km).
Mercury has almost no
atmosphere.
Mercury is made of solid
rock and is covered with
craters.
Mercury
Mercury’s day = 59
Earth days.
Mercury’s year = 88
Earth days.
Mercury has 0 moons
and no rings.
Mercury has the
greatest temperature
difference between
day and night.
Mercury
Mercury’s tilt of axis is
2o.
Mercury has been
visited by: Mariner 10
(1974) and Messenger
(2008).
Venus
Venus has been
known since the
ancients.
Venus is the 2nd
planet from the sun
(.72 AU) and the sixth
largest (12,100 Km).
Venus has a thick
atmosphere of carbon
dioxide (90 X’s more
pressure than Earth).
Venus
The thick atmosphere
traps in heat making
Venus the hottest
planet with a runaway
greenhouse effect.
The surface is rocky
and very hot.
Venus
Venus’ day = 243 Earth
days.
Venus’ year = 225 Earth
days.
Venus’ day is longer than
it’s year.
Venus has 0 moons and
no rings.
Venus rotates opposite of
the other planets.
Venus
Venus’ tilt of axis is
177o.
Venus has been
visited by:
Mariner 2, 5, & 10
Venera 2 – 16
Pioneer Venus 1 & 2
Magellan
Venus Express
Earth
Earth is the third planet from the sun (1.00 AU) and the
fifth largest (12, 746 Km).
Earth’s atmosphere consists of 78% Nitrogen, 21%
Oxygen, and 1% other gases.
Earth has rocky surface and it’s atmosphere and
distance from sun allows for 71% of the surface to be
covered with liquid water.
Earth
Earth’s day = 24 hours.
Earth’s year = 365 ¼ days.
Earth is the only planet with life.
Earth has 1 moon and no rings.
Earth
Earth’s tilt of axis is 23.5o.
Moon
The moon is the 5th
largest moon in the solar
system.
6 Apollo missions landed
on the moon.
The moon has 1/6th the
gravity of Earth.
The moon takes 27.3
days to rotate once.
Mars
Mars has been known
since the ancients.
Mars is the 4th planet
from the sun (1.52 AU)
and the seventh largest
(6,800 Km).
Mars has a thin
atmosphere that contains
mostly carbon dioxide.
The rocky surface
appears red due to the
iron oxide (rust) in the
soil.
Mars
Mars’ day = 24 hours &
37 minutes.
Mars’ year = 687 Earth
days.
Mars has 2 moons and
no rings.
Mars has the largest
volcano in the solar
system; Olympus Mons
(3 times taller than Mt.
Everest).
Mars may have had liquid
water at one time.
Mars
Mars’ tilt of axis is 25.2o.
Mars has been visited by:
Mariner 4
Mars 2
Viking
Phoenix
Pathfinder
Expedition
Moons of Mars
Phobos
Deimos
Asteroids
Smaller than a planet but larger than a
meteoroid
Asteroid Belt
Lies between
Mars and Jupiter
Gravitational pull
of the Sun and
Jupiter did not
allow them to
form a planet
Jupiter
Jupiter has been
known since the
ancients.
Jupiter is the 5th
planet from the sun
(5.2 AU) and is the
largest (143,000 Km).
Jupiter consists
mostly of Hydrogen
and Helium. If larger it
could have become a
star.
Jupiter’s Red Spot
Jupiter’s day = 9
hours & 50 minutes.
Jupiter’s year = ~ 12
Earth years.
Jupiter has 63 moons
and 3 thin rings.
Jupiter has a large
storm called the Great
Red Spot.
Jupiter
Jupiter’s tilt of axis is
3o.
Jupiter has been
visited by:
Pioneer 10 & 11
Voyager 1 & 2
Ulysses
Galileo
Moons of Jupiter
The 4 largest moons of Jupiter are called
the Gallilean moons.
These moons were first observed by
Galileo in 1610.
Io
Io is the fifth moon of
Jupiter. It’s the third
largest of Jupiter’s
moons.
Io has hundreds of
volcanic calderas.
Some of the volcanoes
are active.
Europa
Europa is the sixth of
Jupiter’s moons and is
the fourth largest.
It is slightly smaller than
the Earth’s moon.
The surface strongly
resembles images of sea
ice on Earth. There may
be a liquid water sea
under the crust.
Europa is one of the five
known moons in the solar
system to have an
atmosphere.
Ganymede
Ganymede is the
seventh and largest of
Jupiter’s known
satellites.
It is the largest moon
in the solar system.
Ganymede has
extensive cratering
and an icy crust.
Callisto
Callisto is the eighth of Jupiter’s known satellites
and the second largest.
Callisto has the oldest, most cratered surface of
any body yet observed in the solar system.
Saturn
Saturn has been known since the ancients.
Saturn is the sixth planet from the sun (9.54 AU) and the
second largest planet (120,535 Km).
Saturn is made of materials (hydrogen and helium) that
are less dense than water. If you could fit Saturn in a
lake, it would float!
Saturn
Saturn’s day = 10
hours & 30 minutes.
Saturn’s year = ~ 29.5
Earth years.
Saturn has 60 moons.
Saturn is known for
it’s large rings (7).
Saturn
Saturn’s tilt of axis is 26.7o.
Saturn has been visited by:
Pioneer 11
Voyager 1 & 2
Cassini
Saturn’s Moon Titan
Titan is the 2nd largest
moon in the solar
system.
Titan has it’s own
atmosphere.
Uranus
Uranus was discovered
by Sir William Hershel in
1781.
Uranus is the seventh
planet from the sun
(19.2 AU) and third
largest (51,120 Km).
Uranus is made of
hydrogen, helium, and
methane.
Uranus is blue-green
because of the methane
in its atmosphere.
Uranus
Uranus’ day = 17
hours.
Uranus’ year = 84
Earth years.
Uranus has 27 moons
all named after
Shakesperean
characters and 11
thin rings.
Uranus rotates on it’s
side.
Uranus
Uranus’ tilt of axis is
97.8o.
Uranus has been
visited by:
Voyager 2
Neptune
Neptune was discovered
using math after noticing
variations in Uranus’
orbit.
Neptune is the eighth
planet from the sun
(30.06 AU) and fourth
largest planet (49,530
Km)
Neptune is made of
hydrogen, helium, and
methane.
Like Uranus, the methane
gives Neptune its color.
Neptune
Neptune’s day = 16 hours
Neptune’s year = 164
Earth years
Neptune has 13 moons
and six thin rings.
Neptune has the
strongest winds in the
solar system.
Neptune has a giant
storm called the Great
Dark Spot.
Neptune
Neptune’s tilt of axis
is 28.3o.
Neptune has been
visited by:
Voyager 2
Dwarf Planets
A dwarf planet is any
object that orbits the
sun, is round because
of its own gravity, but
has not cleared its
orbital path.
Pluto, Eris, Quaoar,
Haumea, Makemake,
and Sedna are
examples.
Kuiper Belt
The Kuiper Belt is the
region beyound
Neptune’s orbit.
Hundreds of objects
have been discovered
in this area ranging
from small chunks of
ice to objects similar
in size to Pluto.
Oort Cloud
The Oort cloud is a
spherical cloud of dust
and ice that lies far
beyond Neptune’s orbit
and contains billions of
comet nuclei.