Download Astronomy Review HOW SCIENTISTS BELIEVE THE SOLAR

Astronomy Review
HOW SCIENTISTS BELIEVE THE
SOLAR SYSTEM FORMED
The Big Bang Theory:
•The universe began with a
big explosion some10-15
billion years ago
•All matter was condensed
into a tiny spot and for some
reason it exploded and
formed what we know as the
universe … evidence for this
theory is that the universe is
still expanding and being
formed.
HERE’S WHY SCIENTISTS BELIEVE THE UNIVERSE IS
EXPANDING
RED SHIFT
LIFE CYCLE OF A STAR
STAGE 1: NEBULA
A Nebula is a cloud of
dust and gas.
Nebulae are the
birthplace of stars.
HORSESHOE NEBULA
STAGE 2: Main Sequence Star
• Our sun is a main sequence star
STAGE 3: Giant or Supergiant
• A supergiant burns cool so it glows red
STAGE 4: White Dwarf
• This is very small (about the size of Earth), hot star,
the last stage in the life cycle of an average size
star like the Sun.
Hertzsprung-Russell Diagram
(H-R diagram)
 Stars are ranked based on their temperature
and absolute magnitude.
O
B
A
F
G
K
M
GALAXIES
•There are 3 types: Elliptical, Irregular and Spiral
Spiral
Identified by its spiral arms
The Milky Way is a spiral galaxy of about 200 billion
stars
*Note the position of the sun in the Milky Way
THE SUN
Layers of the Sun
1. Photosphere
• this is the visible surface of the Sun
• the layer where most of the
light comes from
2. Chromosphere
• only visible during a solar
eclipse or with special filters…
appears as a red circle or ring
around the sun during the
eclipse
3. Corona
•only visible during a solar eclipse or with
special filters…appears as white glow
that extends several million miles into
space
Sunspots
•Cooler areas on the photosphere that last for
about 2 months
•Sunspot cycle occurs about every 11 years
THE INNER PLANETS
VENUS
•Second from the Sun and similar to Earth in
size and mass, therefore known as EARTH’S
TWIN
•Has an extremely dense atmosphere of
clouds, therefore making it the hottest planet
in the solar system
THE EARTH
LAYERS OF THE ATMOSPHERE
Which layer does weather occur in?
Where do you find the ozone layer?
Where do you find the jet stream?
Troposphere:
weather,
clouds, and smog are found here
Stratosphere
•contains the ozone (O3) layer
•The ozone layer can be
depleted by chlorofluorocarbons
also known as (CFC’s).
•CFC’s contribute to global
warming
The Jet Stream is also
found in the Stratosphere
EARTH’S TILT CAUSES SEASONS
The hemisphere tilted toward the Sun receives
more daylight hours than the hemisphere tilted
away from the Sun therefore:
1. When the North Pole is in the sunlight, the Northern
Hemisphere is having SUMMER.
2. When the North Pole is in darkness, the Northern
Hemisphere is having WINTER.
SOLSTICES
The day when the Sun reaches its greatest distance
north or south of the equator
1. Summer Solstice---occurs June 21 or 22 in
the northern hemisphere
2. Winter Solstice---occurs December 21or 22 in
the northern hemisphere
SUMMER SOLSTICE
WINTER SOLSTICE
EQUINOXES
The day when the Sun is directly over Earth’s equator
12 hours of daylight and 12 hours of darkness on
equinox days
1. Spring equinox occurs on March 20 or 21 in
the northern hemisphere
2. Fall equinox occurs on September 22 or 23
in the northern hemisphere
FALL (Autumnal) EQUINOX
SPRING (Vernal) EQUINOX
PHASES OF THE MOON
New Moon
Waxing Crescent
Waning Crescent
1st Quarter
3rd Quarter
Waxing Gibbous
Waning Gibbous
Full Moon
ASTEROID BELT
•Made from rocks that are similar to that which
formed planets
•Most asteroids lie in an asteroid belt located
between Mars and Jupiter
THE OUTER PLANETS
THE GAS GIANTS
•Are made completely of gas, and may have a solid
rocky core
Are the largest of all the planets in the solar system
Have numerous moons and very thin atmospheres
JUPITER
•fifth planet from the Sun
• largest planet in the solar system
•a stormy ball of mostly hydrogen
and helium
•the Great Red Spot is the most
spectacular of Jupiter’s many
constant high-pressure gas storms…
winds up to 400 m/hr
SATURN
•Sixth planet from the Sun, second largest in the solar
system, lowest density…it would float on water if you could
find a big enough tub
•Thick atmosphere of hydrogen and helium
COMETS
Made of dust and rock mixed with
water, methane, and ammonia
As it approaches the Sun, its
structure changes
The icy comet begins to
vaporize
Solar winds push on the gases in
the comet
Tails always point away from
the sun