Bodies of our Solar System

Bodies of our Solar System
Section 1.4 p. 392-400
Section 1.5 p. 401-404
Learning Outcome
• Identify evidence for, and escribe characteristics of, bodies that make
up our solar system; and compare their composition and
characteristics with Earth
• Describe the position of objects in space, using angular coordinates
(i.e. the location of a spot on a wall, by identifying its angle of
elevation and its bearing or azimuth (Horizon Coordinates)
Protoplanet Hypothesis
• We learned last class that stars are created
by a nebula, cloud of dust and gas that
with the help of gravity get compressed
and start to heat up creating a protostar
• The Protoplanet Hypothesis is a model to
help explain the birth of solar systems
• Three Steps
• 1. A cloud of gas and dust in space begins
swirling
• 2. Most of the material (more than 90%)
accumulates in the center, forming the sun
• 3. The remaining material accumulates in
smaller clumps circling the center. These form
the planets
• Remember our galaxy is the Milky Way
The Sun
• The sun is 110 times wider than Earth
• If the sun was hollow, you could almost fit a million Earths inside of it
• Temperature on Surface is 5000 degree’s Celsius
• Temperature in the core is 15,000,000 degree’s Celsius
• The sun release’s charged particles in every direction known as Solar
Wind
• Earth is protected by the solar wind due to its magnetic field
The Planets
• Every planet in our solar system is
different, just as the every member of your
family is different
• Has it own unique features and characteristics
• 2 Types of Planets
• Terrestrial Planets (Inner Planets)
• Tend to be smaller in composition
• Closer to the sun
• Jovian Planets (Outer Planets)
• Large and Gaseous
• Located farther from the sun
• What does it take to be a planet
• Is in orbit around the sun.
• Is round or nearly round.
• Has "cleared the neighborhood" around its
orbit, meaning it is not surrounded by objects
of similar size and characteristics.
Mercury
• Closest planet to the sun
• Surface is very similar to the moon
• No Atomosphere, so it has no protection from meteroids and
asteroids, and comets
• (scars of millions of years of collisions can bee seen)
• Temps vary greatly
• 400 degrees on the sunny side
• -180 degrees on the dark side
Venus
• Similar to Earth in diameter, mass, and gravity
• Often called Earths twin
• Horrific Conditions
• Thick gas cloud cover make for green house like conditions
• Temps up to 450 degrees Celsius
• Atmospheric pressure about that 90 times here on earth
• Russians landed a probe on Venus, that only survived 57 minutes
Earth
• Very Unique
• Only planet where water exists in all three phases (solid, liquid, gas)
• Appropriate distance to support life
• Atmosphere provides protection from cosmic rays (uv rays) that harm
life
• One of the few places in the solar system that has active volcanism
Mars
• Referred to as the Red Planet
• This is caused by large deposits of Iron Oxides
• Has two large Ice Caps
• One of which is composed of CO2, and Water
• The other just of CO2
• Very thin atmosphere composed mainly of CO2
• Temperature ranges but averages to be extremely cold
• Has two small moons
Jupiter
• Jupiter has been observed by Telescopes since the 1600’s
• Largest of all the planets in the solar system (more than twice the
mass)
• Has 16 moons
• Composed mostly of hydrogen and helium gas
• Scientist speculate that if it were 10 times bigger, it may have formed
into a star
Saturn
• Could see the rings of Saturn with a primitive telescope
• 19 moons
• Second largest planet
• Has over a thousand rings made up mostly of ice and dust
Uranus
• Another Gas Giant
• Composed mainly of hydrogen and helium
• Atmosphere consists of Methane (gives it it’s distinctive blue color)
• 17 moons
• Rotates orbit on its side, and opposite direction of Earth
Neptune
• Similar to Uranus
• Gas giant consisting of hydrogen, helium, and methane
• Similar size and appearance as Uranus
• Recieves very little energy from the sun
• Gives off 3 times more energy than it receives
• Boasts fastest wind speed 2500 km/h
• Like all other gas giants has its own ring system
• 8 Moons
Pluto
• Discovered in 1930
• It is a frozen ball of methane smaller
than our moon
• Doesn’t fit the pattern of outer
planets that tend to be large and
gaseous
• But yet isn’t rock like terrestrial planets
• Some believe that Pluto and its
moon (Chaon) are comets captured
by the suns Gravity
• It 2006 it was determined not to be
a planet as it could not meet the 3rd
criteria
Other Bodies in the Solar System
• Asteroids
• Metallic bodies traveling in space
• Between mars and Jupiter lies a narrow belt of them
• Range in size from a few meters to several hundred km’s
• Largest one (Ceres) is 1000 km’s wide
• Scientists are unsure where they came from
• Comets (dirty snowballs)
• Objects made up of dust and ice
• Long tails and bright glow only appear when they get close
to the sun
• Sun heats the material of the comet releasing gases
• Tails can million of Km’s long
• Comets that orbit the sun will make regular appearances
• Halley comet, which is visible from earth every 76 years (last seen
in 1986)
Meteoroids, Meteors, and Meteorites
• Small pieces of rocks flying
through space with no particular
path are called Meteoroids
• Can be small as a grain as sand, or
large as a car
When gravity pulls one into Earths
atmosphere, the atmospheric
friction causes it to give off light and
it is known as a meteor
If the meteor lasts long enough to
hit Earths surface it is called a
meteorite
Tracking Orbits in the Solar System
• Because Astronomers understand the nature and geometry of
elliptical orbits, as well as celestial motion, they now understand the
paths of planets and their moons
• This means that they can predict many different events well before
they happen
• solar and lunar eclipses
• when comet sightings will occur
Describing Positions in Space
• It is important to be able to have a consistent means
to describe the location of objects in our sky
• To do this two questions must be answered
• How high is the object
• In which direction is the object
• Azimuth is a term used to refer to compass direction
• North is 0 degrees, south is 180 degrees, west is 270
degrees
• Altitude is used to refer to high in the sky is the
object
• Ranges from 0 to 90 degrees
• With these two measurements scientists can pinpoint
objects in space
• Zenith refers to the highest point directly overhead