Transcript Components of the Solar System Chapter 16

Components of the Solar
System
Chapter 16
Our Solar System
► The
solar system is the name given to the
planetary system of which the Earth is a part.
It also contains planets, moons, comets,
meteors and asteroids which are all held
together by the gravitational pull of a star
named the Sun.
► As the Sun began to heat up, gravity began to
pull-in dust an gases, which clumped together
and form our planets. Rocks that did not
become large enough to form planets
remained as asteroids.
16-1 Describing the Solar System
► Ancient
Greeks watched the stars in the sky. They
noticed that some stars moved, they called the
objects “planets” which meant wandering star.
► Geocentric System-Most Greek astronomers believed
that Earth(geo) was at the center of the universe and
everything revolved around it.
► Ptolemy believed in a geocentric system and that
planets move on little circles that move on bigger
circles. His ideas were believed for over 1,400 years.
► Copernicus
believed the sun was at the center
of the universe.
► Heliocentric
System-stated that Earth and the
other planets revolved around the Sun(Helios)
► Galileo
believed in the heliocentric system. He
was the 1st scientist to use a telescope to look
at objects in the sky. He saw moons revolve
around Jupiter and Venus go through phases
similar to our moon.
► This
explained that Ptolemy’s geocentric
system could not be correct, so we have now
named our universe the Solar System.
►
Geocentric System
Heliocentric System
► In
the late 1500’s Tycho Brahe(Danish),
observed the positions of the planets for
almost 20 years.
► In
the 1600’s Johannes Kepler(German
mathematician), discovered that the orbits
of each planet is an ellipse, elongated circle
or oval shape.
► Isaac
Newton concluded that two factors
keep the planets in orbit-gravity and inertia.
► Inertia
is the tendency of a moving object to
stay in motion and a stationary object to stay
in place.
► Gravity
is the force that attracts all objects
toward one another. Gravity depends on the
masses of the object and the distance between
them.
► The solar system is a large system that consists
of a combination of many smaller systems
and objects.
► It is hard to determine where our solar system
ends. It ends at the point at which objects are
no longer affected by the sun’s gravitational
pull, solar wind and the sun’s magnetic field.
Some believe it ends at the Oort Cloud outside
the Kuiper Belt.
16-2 Characteristics of the Sun
► The
sun is a ball of glowing gas and does not
have a solid surface. The sun produces
energy in a process know as nuclear fusion.
► Nuclear fusion is where hydrogen atoms join
together to form helium-this occurs under
extreme temperatures and pressure in the
sun’s core.
► The energy released includes light and heat,
when it reaches Earth it is our main source of
energy.
►The
sun has three layers:
►The photosphere(light)-the inner layer,
what you see when you look an image or
photograph of the sun
►The chromosphere(color)-the middle
layer, what you see at the beginning and
end of a total solar eclipse.
►The corona(crown)-the outer layer, a
white layer around the sun only visible
during eclipses.
► Solar
winds are a stream of electrically charged
particles sent out from the sun’s corona. They
can cause auroras if they enter our atmosphere.
► Sunspots-dark areas of gas on the sun that are
cooler than other gases around them. Sunspots
go through cycles every 10-11 years.
► Prominences-reddish loops of gas that link
sunspot regions.
► Solar Flares-explosions of hydrogen gas formed
when loops in sunspot regions suddenly connect.
They increase the solar winds, cause magnetic
storms and can interfere with satellite signals.
16-3 The Inner Planets
► Known
as the terrestrial planets(land/Earth)-the
four inner planets are small and have rocky
surfaces.
► Mercury-Closest to the sun with no moons, due
to no known atmosphere it has the greatest
range of temperatures of all planets.
► Venus-Second planet from the sun, known as
Earth’s twin-it shines very bright in the sky. It’s
day is longer than its year and it has a retrograde
rotation which means it rotates backwards.
Venus has a very thick, hot atmosphere caused
by the trapping of heat or the greenhouse effect.
► Earth-Third
planet from the sun and the only
planet with water and life as we know it.
► Mars-Fourth planet from the sun and known
as the “red planet”. Mars has 2 moons and
an atmosphere made mostly carbon dioxide. It
has seasons like Earth because of the tilt of its
axis.
16-4 The Outer Planets
► The
first four outer planets are much larger than
Earth, do not have solid surfaces and are known
as gas giants. They are believed to have partly
solid cores.
► Jupiter-The largest planet in the solar system. It
has a Great Red Spot storm, similar to a
hurricane on Earth. Jupiter has four main
moons and about 17 others.
► Saturn-The second largest planet in the solar
system and the only planet less dense than water.
Saturn has a visible ring system and several
moons.
► Uranus-The first
planet discovered since
ancient times by William Herschel, it looks
blue due to methane in its atmosphere.
Uranus has many moons and rotates on its
side.
► Neptune-Like Uranus, it has a blue, methane
atmosphere. It was discovered as a result of a
mathematical prediction. Neptune has faster
winds than any other planet.
► Pluto-The fifth outer planet, it is different
from the other outer planets, because it is
small and rocky like the inner planets.
► Pluto
was discovered in 1930 by Clyde
Tombaugh. Pluto has one main moon Charon
and two other smaller moons. Pluto and its
moons are so far away from the sun that it
takes 248 Earth years to make one orbit of the
sun.
16-5 Comets, Asteroids and Meteors
►
Like each planet, each comet is a small system within the
large solar system.
► Comets(long haired stars)- are large chunks of ice and dust
whose orbits are usually very long, narrow ellipses. They are
similar to a “dirty snowball” about the size of a mountain on
Earth. Comets have three parts: The coma-an outer layer
made of dust and gas, the nucleus-the inner layer and the
tail-gas and dust pushed away by solar winds. Halley and
Hale-Bob are two well known comets.
► Asteroids
are objects too small and numerous to be
called planets. Asteroids were first discovered in
1801-1807 between the orbits of Mars and Jupiter,
an area now known as the asteroid belt. Some well
known asteroids are Ceres, Pallas, Juno, and Vesta.
An asteroid hit Earth about 65 million years ago and
Scientists believe this caused dinosaurs to become
extinct.
Asteroid Belt
►A
meteoroid is a chunk of rock or
dust in space that usually comes from
comets or asteroids.
►A
meteor is a streak of light you see
when a meteoroid has encountered
friction in Earth’s atmosphere and
burned up. Meteor showers occur
several times a year.
►A
meteorite is a meteoroid that has
passed through Earth’s atmosphere
and hit Earth’s surface. If large
enough they can cause craters.