Transcript Solar System Power Point

Solar System
Sources
• http://csep10.phys.utk.edu/astr162/lec
t/sun/sun.html
• http://www.windows.ucar.edu/tour/link=
/sun/sun.html&edu=high
Our Solar System
• Our solar system includes
the sun, the planets and
many other smaller objects
• Astronomers use
astronomical units to
measure distances in our
solar system
Our Solar System
• An astronomical unit
(AU) is the average
distance between the
Earth and the sun or
150 million kilometers
Solar System
• The solar system is
divided into two main parts
–Inner Solar System
–Outer Solar System
Inner Solar System
• These are the four planets
closest to the sun and are
closely spaced together
• They are known as the
terrestrial planets because
their surfaces are dense and
rocky
Outer Solar System
• These are the four planets
furthest from the sun
• The outer planets are
composed mostly of gases
and are much bigger than
the inner planets
Planets Movement
• Period of Revolution- Time it
takes for a planet to make one
revolution around the sun. This
is called a year.
• Period of Rotation- Time it
takes for a planet to make one
revolution on its axis. This is
called a day
• NEBULA – a large cloud of
gas and dust in interstellar
space
• Two forces interacting in
nebulas:
1. Gravity
2. Pressure
• TEMPERATURE – is a measure of
average kinetic energy of the
particles in an object.
• If particles in a nebula have LOW
kinetic energy, they move SLOWLY
and the temperature of the cloud is
very LOW.
• If particles in a nebula have HIGH
kinetic energy, they move FAST and
the temperature of the cloud is
HIGH.
Gravity and Pressure in a
Nebula
1. GRAVITY causes the particles in a
nebula to be attracted to each
other.
2. As particles move close together,
collisions cause PRESSURE to
increase and particles are pushed
apart
3. If the inward force of gravity is
balanced by outward pressure, the
nebula becomes stable.
• The balance between gravity and
pressure can be upset by:
– Two nebulas collide
– A nearby star explodes
• When the balance is upset –
small regions of the nebula are
compressed and form
GLOBULES (GAS CLOUDS)
• Globules - very dense - contract
under their own gravity –
collapses inward
• Temperature increases - THE
STAGE IS SET FOR STAR
FORMATION
• SOLAR NEBULA – the cloud and
dust that formed our solar
system
HOW THE SOLAR SYSTEM
FORMED
1. Young solar nebula BEGINS TO
COLLAPSE – it took about 10
MILLION years for the solar
system to form.
2. The solar nebula rotates, flattens,
and becomes warmer near its
center.
3. PLANETESIMALS begin to form
WITHIN THE SWIRLING DISK.
• A PLANETESIMAL is a small
planet
4. As the largest planetesimals grow
in size, their gravity attracts
more gas and dust.
5. The smaller planetesimals collide
with the larger ones, and planets
begin to grow.
6. A star is born, and the remaining
gas and dust are blown out of the
new solar system.
The Outer Planets
• The largest planetesimals formed
near the outside of the rotating
solar disk, where hydrogen and
helium were located.
• These outer planets grew to huge
sizes and became gas giants
• * SOL QUESTION – Jupiter’s
“Great Red Spot” is a storm
system more than 400 years old
and about 3x the diameter of
Earth
The Outer Planets
Are Jupiter, Saturn,
Uranus and Neptune
THE INNER PLANETS
• Closer to the center of the
nebula temperatures were
TOO HOT for gases to
remain
• Therefore the inner
planets are made mostly of
ROCKY MATERIAL.
The Inner Planets
Are Mercury, Venus
Earth and Mars
Mercury
• Very similar to
our moon
(rocky, lots of
craters)
• Rarely see (too
close to sun)
• Very thin
atmosphere
Venus
• Earth’s twin (similar
diameter, mass, density)
• Hottest planet because
of greenhouse effect
• Very thick clouds
• Active Volcanoes
• Retrograde Rotation
(Day is longer than
year)
• Mapped using radar
Mars
• Evidence of liquid
water – Dust storms
• Tallest mountain in
solar system= Olympus
Mons
(3x Everest)
• Valles Marinaris
(Width of US)
• Polar Ice caps (CO2)
• Fossils?
• 2 Moons: Phobos &
Deimos
Fossils on Mars?
Olympus Mons & Valles Marineris
Ice Caps on Mars
Asteroid Belt
• Failed planet?
• All matter in
asteroid belt =
1/10 of our moon
• Located between
Mars and Jupiter
• 100,000 +
• Pebbles – 100s of
Km
BIRTH OF A STAR
• As the planets were forming the
center of the nebula became very
dense and hot that hydrogen atoms
began to fuse to form HELIUM.
• Fusion creates large amounts of
energy and created enough outward
pressure to balance the inward pull of
gravity.
• The gas stopped collapsing and OUR
SUN was born!
Formation of the Sun
Solar Facts
• Mass: 330,000 x Earth
• Diameter: 1.4 million Km
• Temperature Range: 4,000 C (Sunspots)
to 14,000,000 C (Core) Rotational Rate:
25-35 days
• Age: 4.5 Billion Years
• Life Expectancy: 5 Billion years (more)
• Distance to Earth: 150,000,000 Km
• Distance to nearest star: 4.3 Light
Years
PARTS OF THE SUN
1. CORE – center –
where the sun’s
energy is
produced
2. RADIATIVE
ZONE – very
dense region
about 300,000
km. thick
PARTS OF THE SUN
3. CONVECTIVE
ZONE – about
200,000 km.
thick – where
gases circulate
4. PHOTOSPHERE –
visible part that
can be seen from
Earth
PARTS OF THE SUN
5.CHROMOSPHERE
– thin region
below the corona,
only about 30,000
km. thick
6. CORONA –
forms the sun’s
outer atmosphere
• Albert Einstein showed that matter and
energy are interchangeable
• E=mc2
• E=energy, M=mass, c=speed of light
• Since c is such a large number, tiny
amounts of matter can produce a huge
amount of energy
• NUCLEAR FUSION – two or more low
mass nuclei fuse to form another
nucleus.
Nuclear Fusion
• H + H + H + H = He + Energy
• 1 Helium atom is lighter than the 4
Hydrogen atoms, lost mass becomes
energy
• How energy is produced in the center
of stars
• Takes millions of years for energy to
reach the sun’s surface.
• It takes 8.3 minutes for sunlight to
reach the Earth
FOUND ON THE SUN
• The circulation of the convective zone
and photosphere combines with the sun’s
rotation create MAGNETIC FIELDS that
reach far out into space.
• SUNSPOTS are created when the sun’s
magnetic fields slow down activity in the
convective zone resulting in cooler areas
of the photosphere.
• A SUNSPOT is a dark are of the
photosphere that is cooler than the
surrounding areas and has a strong
magnetic field
Map of Sunspots
SUNSPOTS
• Sunspots vary in shape and size
• The numbers and locations of sunspots
change every 11 years – affect climate
• Magnetic field that cause sunspots, also
cause SOLAR FLARES.
• SOLAR FLARES are regions of
extremely high temperature and
brightness that develop on the sun’s
surface
Solar flares sends huge streams of
electrically charges particles into the
solar system.
Solar flares are usually associated with
sunspots and can interrupt radio
communications.