Transcript SOLAR SYSTEM

SOLAR SYSTEM
BEFORE WE GO ON…
Cosmologist – scientist who studies how the world was
formed.
In the beginning…
• Ptolemy (Greek) proposed a theory that planets
orbited the earth (geocentric).
• Copernicus (Polish) changed the theory to planets
orbiting the sun (heliocentric).
• Kepler proved that the planets orbited in ellipses
counterclockwise and not complete circles.
• Newton explained planet motion as a result of
inertia and gravity. Gravity keeps them close to
the sun and inertia keeps them moving.
Rotation versus Revolution
• Rotation – the time it takes a planet to make a
complete circle on its own axis. (Equal to one
day)
• Revolution – the time it takes a planet to circle the
sun completely. (equal to one year)
Shoulder Partner
• Come up with a rhyme or quick saying to
help you remember the difference between
rotation and revolution.
Did you know…?
• The four inner planets are also referred to as
rocky or terrestrial planets.
MERCURY
• Mercury – rocky, almost no atmosphere, sun is 9
times closer, moves around the sun faster than all
other planets. Year = 88 days. No weather. All
volcanoes now dormant. Day = 175 Earth days.
Temp. range 427°C to –170°C. Day longer than
its year.
Face partner
• Why couldn’t we survive on Mercury?
Give at least 3 reasons.
VENUS
• Venus – Earth’s sister planet. Atmosphere
is mostly CO2 and thick cloud cover.
Windy 350 km/hr. Stormy. Deep canyons,
vast plains. Mountains as tall as those on
Earth. Huge channel some believe was
once an ocean. Retrograde motion (sun
rises in west…) Day = 243 earth days. Year
= 224 earth days. Scientists believe ocean
dried up due to greenhouse effect.
Table Talk…
• Why do you think they call Venus the sister
planet to Earth?
EARTH
• A year on Earth is exactly 365.26 days. This is
the reason for a leap year every four years.
Seasons are caused by the tilt of the Earth on its
own axis. When the N hemisphere is tilted
toward the sun it is summer for us; when the S
hemisphere is tilted toward the sun it is their
summer. During an equinox (spring/fall) neither
is tilted toward the sun.
Shoulder partner
• Where do you think our moon came from?
What theories are there on its origin?
MARS
• Mars – Red in color, has two tiny moons Phobos
and Deimos meaning fear and terror. Rocks
found in Antarctica had live bacteria comparable
to our bacteria. Has an enormous dormant
volcano named Olympus Mons (3 times size of
Mt. Everest). Windstorms that are up to 200
km/hr. Dust from these storms cause sky to look
pink.
UHHH…HELLO?
ASTEROID BELT
• Located between Mars and Jupiter.
• Meteoroid – chunk of metal/stone that
orbits the sun.
• Meteor – streak of light produced by a
burning meteoroid.
• Meteorite – a meteor that strikes the
Earth’s surface.
Meteors…
What would happen…
• If the Earth crossed the asteroid belt? Is
there any evidence that this has occurred in
the past?
NOW FOR THE OUTER
PLANETS!
JUPITER
• Jupiter – day = less than 10 hours. Composed
of hydrogen and helium. Belts – low, dark
colored clouds. Zones – high, lightly colored
clouds. Red Spot is a hurricane-like storm that
has been rotating for more than 300 years. Has 4
main moons.(Io, Callista, Europa, and
Ganymede)
SATURN
• Saturn – made mostly of hydrogen and helium.
Has ammonia ice near top of its clouds. Has 18
known moons, giant one named Titan. May
have methane (gas, liquid, and solid “ice”)
similar to water on earth.
URANUS
• Uranus – discovered in 1781. Blue in color. Has
18 moons, 2 big ones named Oberon and Titania.
Has 10 rings. Because it is tilted on its side; each
pole spends 42 Earth years in darkness and 42
years in sunlight. It has a constant temperature of
–215°C because of its atmosphere.
NEPTUNE
• Neptune – discovered in 1846. Slightly smaller
than Uranus but same blue color. Considered the
twin giants. Has clouds and belts like other gas
giants. Once had a great dark spot like Jupiter
but it disappeared in 1994. Has 8 moons, largest
is Triton. Has nitrogen geysers. Also, has a
retrograde motion.
PLUTO
• Pluto – discovered in 1930. Named after the
Roman god for the underworld. Pluto is a little
more than moon-sized and may be an escaped
moon of Neptune. It has a moon named Charon
that is roughly the same size as Pluto. So, the
question remains: What should Pluto be classified
as?
PLANET X
• Planet X – Scientists assume there is
another planet; a big planet on the other side
of Pluto. They think it is this planet or an
object massive enough to pull Uranus on its
side. May be the sister star to the sun
because most stars are in pairs or threes,
rarely are they single.
Does the government think there is life
outside the Earth?
This picture is floating around in outer space on a
satellite to let anyone looking for life find us.
WHEW! WE’RE FINALLY
DONE.