SC.8.E.5.6 - Create models of solar properties including: rotation, structure of the Sun,
convection, sunspots, solar flares, and prominences.
Interior of the Sun
The Sun uses Nuclear Fusion (not Fission) by two Hydrogen atoms “fusing” together into Helium. The sun is 70%
hydrogen and 30% Helium. Nuclear Fusion occurs at the core of the Sun.
The next layer is the radiative zone where it takes light millions of years to pass through this zone. Even though the
photons travel at the speed of light, the energy generated in the core is carried by light (photons) that bounces from
particle to particle through the radiative zone.
The next layer is the convection zone – hot stuff expands and gets less dense so it rises and cool stuff contracts and
gets denser and sinks.
The further down you go into the Sun, the denser it gets.
Atmosphere of the Sun
The surface of the Sun is the photosphere. Chromosphere is the colorful ring you see in a solar eclipse. The corona is
the rays of light. Sunspots are the darker areas of the Sun that are cooler. Solar Flares shoot straight out. Prominences
shoot out but then loop back
SC.8.E.5.7 - Compare and contrast the properties of objects in the Solar System
including the Sun, planets, and moons to those of Earth, such as gravitational force,
distance from the Sun, speed, movement, temperature, and atmospheric conditions.
My Very Educated Mother Just Served Us Nine Pizza Pies:
(Mercury, Venus, Earth, Mars) | (Jupiter, Saturn, Uranus, Neptune)
The first 4 planets are terrestrial planets, the last 4 planets are called either gas giants or Jovian planets (similar to
Jupiter)
The gas giants are way farther away than the terrestrial planets. That is why there haven’t been as many space crafts
that have visited there.
The two major components of the outer planets – They have a massive atmosphere and they are big.
The four largest objects in the solar system after the Sun are the 4 gas planets in this order from largest to smallest:
Jupiter, Saturn, Uranus, Neptune.
Planets that are closer to the Sun orbit, or revolve, around it at a faster pace. Also, when objects go closer to the sun,
such as a comet, it speeds up and then slows down when it goes farther from the sun. It trades off between kinetic
and potential energy. That is why Mercury travels at a faster speed around the sun compared to the gas planets
which are farther away. It has to go faster to counteract the more intense pull of the Sun. The rule is: the smaller the
orbit, the faster the orbiting body travels
All of the gas planets have rings
Density of Saturn - Saturn has the lowest density of all the planets in the Solar System. The actual density is 0.687
grams per cubic centimeter. This is actually less dense than water, which has a density of 1. If you had a large enough
pool of water, Saturn would float in it.
Uranus’s unusual axis of rotation – Uranus is the only planet to rotate on its side. One pole experiences 42 Earth years
of day followed by 42 years of night. When the North Pole is in the Sun, the South Pole is in darkness and vice-versa.
Why Mercury has many impact craters – We see a lot of craters on Mercury because there isn’t much of an
atmosphere. The atmospheres of Venus, Earth and Mars cause the craters to be eroded away by wind and rain. Also,
the outer planets are composed of gas, so they do not have craters. A lack of atmosphere on Mercury also causes
meteoroids to not burn up as they would on Earth where they would become a shooting star, or meteor.
Temperature differences on Mercury due to its atmosphere – Mercury is the closest planet to the Sun, so it can reach
temperatures as hot as 801 degrees Fahrenheit, but it is strange because meanwhile the night side gets as cold as 279 degrees Fahrenheit. This is due to Mercury having the thinnest atmosphere in the solar system. An atmosphere
acts as a blanket keeping the heat from radiating back into space. Without an atmosphere, Mercury loses a great deal
of heat into space, rather than sharing with its night side.
Venus’s greenhouse effect – Venus is the second planet from the Sun, but is the hottest planet and it actually gets
hotter than Mercury. Venus gets so hot due its thick atmosphere of carbon dioxide causing a major greenhouse effect
by capturing the heat and not letting it leak out into space. Venus’s atmosphere is 90 times more massive than
Earth’s.
Venus’s rotation and revolution periods – The period of rotation for Venus is 243 Earth days. In other words, one
Venus day is 243 Earth days long. It takes 116.75 days from sunrise to sunset. That seems like a long time, and it is.
Especially when you consider that a year on Venus only lasts 224.7 days (revolution or orbit). In other words, a day on
Venus lasts longer than its year. Even stranger, Venus is rotating clockwise while the rest of the planets rotate
counterclockwise.
Why Pluto is not a planet – Pluto is not a planet due its smaller size and location. Pluto’s diameter is only 18% of that
of Earth. It is located in the Kuiper belt where over 70,000 objects were found that have the same composition and
are over 100 km across. One object named Eres is actually bigger than Pluto.
To Be a Planet:
1. Has to be in orbit around the Sun (Pluto meets this requirement)
2. Has to have enough gravitational pull to make itself into a spherical shape (Pluto meets this requirement)
3. Has cleared the neighborhood around its orbit (This is where Pluto fails). Earth is 1.7 million times the mass of
any object in its orbit, while Pluto accounts for only 1% of the debris in its orbit.
SC.8.E.5.8 - Compare various historical models of the Solar System, including
geocentric and heliocentric.
If the Earth is at the center, it is geocentric. If the Sun is at the center, it is heliocentric. (Geo = Earth, Helio = Sun)
The geocentric model is the earlier model and the heliocentric is the current model of the solar system.
The guy to remember is Copernicus. He came up with the heliocentric model that everything in our solar system
orbits the Sun, rather than the Earth. Everything orbits the Sun because it contains 99% of the Solar system’s mass
(1.3 million Earth’s can fit inside the Sun). Mass (and distance) are the factors that influence gravity, so because the
Sun is so massive, everything orbits it.
SC.8.E.5.9 - Explain the impact of objects in space on each other including:
1.the Sun on the Earth including seasons and gravitational attraction
2.the Moon on the Earth, including phases, tides, and eclipses, and the relative
position of each body.
1 Revolution (orbit) = 1 Year (seasons change due to the 23.5 degree tilt of the Earth)
1 Rotation (spin) = 1 Day (causes day and night)
Earth’s Tides
The moon and Sun cause the tides, but the moon is closer to Earth so it has more of an impact.
There are two high tides per day and two low tides per day, caused by the moon.
Spring tides are the 2 largest tides in the month when the Sun, Earth and moon are in line with each other. The Sun
and moon’s gravity work together to get larger tides.
Neap tides are the 2 smallest tides in the month when the Sun and moon are perpendicular (90 degree angle) to the
Earth. The gravity of the Sun and moon work against each other in this case, which produces smaller tides.
Normal high and low tides refer to just the moon’s impact, while . . .
Spring and neap tides refer to the moon AND the Sun’s impact on Earth’s water.
A tidal range is the difference between high and low tides
Phases of the Moon
The stages of the moon are new moon (no light), crescent (less than half lit), quarter (half lit), gibbous (more than
half lit), and full moon (fully lit).
The action verbs describing the light of the moon are Waxing = getting brighter; Waning = Getting dimmer
“When its light on the right, it’s going to get bright” (waxing). Then naturally the opposite would be that if it is light on
the left it is getting dimmer (waning)
So all the phases from start to finish would be:
new moon, waxing crescent, 1st quarter, waxing gibbous, full moon, waning gibbous, 3rd quarter, waning crescent,
back to new moon.
Solar and Lunar Eclipse
When the moon blocks the Sun’s light, it makes a solar eclipse. You can see a colorful ring around the moon – that is
the chromosphere.
When the Earth blocks the Sun’s light going to the moon, it makes a lunar eclipse. You would think that it would look
like a new moon, but it is actually red and is also called a blood moon.
SC.8.E.5.11 - Identify and compare characteristics of the electromagnetic spectrum
such as wavelength, frequency, use, and hazards and recognize its application to an
understanding of planetary images and satellite photographs.
Visible
Light - ROY G. BIV – Red, Orange, Yellow, Green, Blue, Indigo, Violet
We can only see the visible light wavelengths, but we have satellites that can detect the other wavelengths. Images
from the other wavelengths are reveal information that the visible light does not show.