Download The Solar System

The Solar System
The Sun and the Planets
What does the solar system consist of?
• The Sun, the eight planets and their moons,
and billions of other smaller objects.
• All of these celestial objects orbit the Sun.
Measuring Distances in the Solar
System
• Distances in the Solar System are so astronomical
that “kms” is not enough!
• Instead, astronomers use the astronomical unit to
measure the distances within our Solar System.
• 1 AU = 150, 000, 000 km and it represents the
average distance between the Sun and the Earth.
(Jupiter is 780 million km from the Sun
which = 5.2 AU)
Planets Big and Small
• The four planets nearest
the Sun are M, V, E and
M. These small rocky
planets make up the inner
part of the Solar System.
• The four planets beyond
Mars are J, S, U, and N.
These planets are gas
giants.
On your Solar System Map
Label:
– All 8 planets
– Label the terrestrial
planets and the gas giants.
Dwarf Planets
• To be considered a true planet, a celestial
object must:
– Be in orbit around a star (Such as the Sun)
– Have enough mass to be pulled into a stable
sphere by gravity
– Dominate its orbit (Its mass must be greater than
anything else that crosses its orbit)
Why is Pluto No Longer a Planet?
• From 1930 – 2006 Pluto was considered to be the
ninth planet in the Solar System.
• New definitions of planets excluded Pluto and
added it to the “Dwarf Planet” category due to the
fact its tilted orbit crosses the orbit of Neptune.
– Astronomers suspect there are up to 2000 Dwarf
planets, with as many as 200 in the region of the outer
Solar System called the Kuiper Belt
Add the Kuiper Belt onto your
Solar System Map beyond Neptune
Why is Pluto No Longer a Planet?
• http://videos.howstuffworks.com/tlc/29944solar-empire-pluto-video.htm
• http://videos.howstuffworks.com/discovery/28
845-discover-magazine-pluto-planet-or-notvideo.htm
Dwarf Planets
• Dwarf planets orbit the Sun and have a spherical
shape BUT they do not dominate their orbits!
• Currently, there are 5 recognized dwarf planetsCeres, Pluto, Haumea, Makemake, and Eris.
• Most of the dwarf planets discovered lie beyond
Neptune’s orbit.
(Add these 5 dwarf planets onto your Solar System
Map beyond Neptune in the Kuiper Belt)
Smaller Members of the Solar System
• Asteroid Belt
– Asteroids are small celestial objects composed of
rock and metal.
– They are too small to be considered planets.
– The vast majority of asteroids lie in an area known
as the asteroid belt, located between the orbits of
Mars and Jupiter. (Add the Asteroid Belt onto your
Solar System Map)
– Asteroids vary in size and shape (some round but
most are irregular).
Meteoroids
• A meteoroid is a piece of metal or rock in the
Solar System that is smaller than an asteroid.
• Sometimes meteoroids get pulled in by Earth’s
gravity. As they enter Earth’s atmosphere,
friction causes them to burn up creating a streak
of light across the sky known as a meteor.
• On rare occasions, larger meteors that do not
burn up completely and actually crash to the
ground are now called meteorites.
Meteorite Impacts
• On February 15th, 2013 a meteor entered the
atmosphere above Chelyabinsk, Russia.
– It was travelling at a speed of 18 km/s or 40 000 mps
– Exploded with a total energy of 440 kilotons of TNT
(20 – 30 x that of an atomic bomb)
• 90 tons was emitted as visible light and was seen as far as 6
cities away.
– There were 1500 injuries, mostly from indirect effects.
– The meteorite had a mass of 11 000 tonnes and was
17 – 25 m wide, it is the largest to hit earth since 1908
It was not detected before it entered the
atmosphere!!!!
Chelyabinsk Meteor
– Video:
http://www.space.com/19807-raw-video-meteoritecrash-in-russia-sparks-panic.html
http://news.discovery.com/space/videos/spacevideos.htm
Meteorite Impacts
• Several large meteorites have been known to
create craters on impact.
Canadian Connection
• The second largest impact crater in the world
is the Sudbury Basin, located in Northern
Ontario.
• It was formed by a 10 km meteorite impact
that occurred 1.85 billion years ago.
• Much of the nickel mined in the Sudbury area
today originated from this meteorite!
Comets
• Comets are large chunks of ice, dust, and rock
that orbit the Sun.
• Some comets take a few years to travel
around the Sun, while others can take
hundreds of thousands of years!
• When a comet gets close enough to the Sun,
its outer surface begins to sublimate-and its
icy nucleus heats up.
Comet Hale- Bopp & Halley’s Comet
• The Comet Hale- Bopp is the most recent
long- period comet to be observed on earth
and will take 2380 years to make 1 trip around
the Sun.
• Halley’s Comet last visited in
1986 and will return in 2061.
Comets
• As this happens, gases and dust escape
forming a gaseous cloud around the nucleus
called a coma.
• As a comet approaches the Sun, solar wind
pushes on the coma, creating a gaseous tail to
form.
• The direction of the tail points away from the
Sun and tells you which direction it came
from.
Did you Know?
I AM A COMET
Comet
CometShoemakerShoemaker-Levy
Levy 99
• Crashed into Jupiter in
July 1994 after it
ventured too close to
the planet and was
pulled in by the planet’s
gravity.