Download Chapter 3 Section 2 (pgs 68-73) the sun`s outer atmosphere – this is

7th Grade Astronomy Notes
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Chapter 3 Section 2 (pgs 68-73)
Describe the role of each of the sections of the sun:
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Corona: the sun’s outer atmosphere – this is the “halo” we can see around
the sun.
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Chromosphere: this is a thin region below the corona that is around 30, 000
km thick.
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Photosphere: this is the “surface” of the sun that we can see from Earth with
protective lenses (NOT sunglasses!!!).
Convection Zone: this is a region of circulating gases about 200, 000 km thick.
Radiative Zone: a 300, 000 km thick region of densely packed particles of gas
where energy from the core travels for a long period of time to get to the
convective zone (~1 million yrs).
Core: this is where the energy of the sun is produced in the process of
nuclear fusion.
What were some of the original theories for how the sun gets its energy?
There were three original theories of how the sun produced its energy: the first
theory was that the sun was burning its fuel (a fire of sorts); the next theory was
that the sun was shrinking and gravity was causing the release of energy; finally
the last theory was that the sun was converting mass to energy through nuclear
fusion.
Why were some of these theories incorrect?
These theories were wrong because the processes of burning the fuel or the
shrinking of the sun would have caused the sun to stop releasing energy (burn
out) a long time ago.
How does the sun get its energy? The sun gets its energy from the process of nuclear
fusion.
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7th Grade Astronomy Notes
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How long does the energy from the sun’s internal process take to reach the outer layers of the
photosphere? It takes around a million years for the sun’s energy to reach the
photosphere from the core because the radiative zone is very dense with gas
particles.
What are sunspots? How are they caused?
Sunspots are areas of the sun’s photosphere that are cooler than the regions of
gas that surrounds them. Sunspots are caused by changes in the sun’s magnetic
field.
What are solar flares and how do they form?
Solar flares are regions of high temperature and brightness that develop on the
sun’s surface. They look like expulsions from the sun and release large amounts
of EM radiation.
What are some possible effects on Earth due to these sunspots and solar flares?
Some of the possible effects of the sunspots and solar flares are a change in
climate conditions for a short period of time. Another danger of solar flares and
sunspots is the possible damage to electronic equipment (radios, cell phones,
GPS, etc.) in space and on Earth.
Chapter 1 Section 2 (pgs 8-13)
What tool do astronomers use to look into and study space?
Scientists use telescopes to look into and study space. A telescope is a device
that collects EM radiation from the sky and concentrates it for better
observation.
What are the two types of these tools?
1. Refracting telescopes
2. Reflecting telescopes
What are some disadvantages of refracting telescopes?
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7th Grade Astronomy Notes
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1. Objective lens – the lens does not allow for all colors of light to be focused
clearly (there will be blurriness).
2. Objective lens – limits the size of the telescope – the lens will cause distortion
of the image when the lens gets too big
What are some advantages for the reflecting telescopes?
1. By using mirrors instead of glass, the size of the telescope can be of any size.
2. The mirrors are able to focus all colors of light to the same focus point and will
not cause any distortion.
3. The use of polished mirrors takes the defect error out of using an objective
lens.
How does the atmosphere affect the optical telescopes? The atmosphere can cause a
distortion (blurriness) in the star’s light because of pollution (light and smoke)
and the gases moving in our atmosphere
What is the Electromagnetic Spectrum? The electromagnetic spectrum is a collection of
all different forms of electromagnetic radiation that includes: Radio Waves,
Microwaves, Infrared, Visible Light, Ultraviolet Waves, X-Rays, and Gamma
Rays.
What is another type of telescope that scientists use? Scientist can also use non-optical
telescopes to pick up EM radiation other than visible light.
Where are these telescopes located at and why? These telescopes are mostly located in
space because most of the EM radiation is blocked by the Earth’s atmosphere
and cannot be observed from the surface of Earth.
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7th Grade Astronomy Notes
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Chapter 3 Section 4 (pgs80-83)
What is the difference between orbit, revolution, and rotation? What events, here on Earth, are
denoted by these actions? A rotation is when a planet spins on its own axis; here on
Earth we call this a day. A revolution is when a planet or moon orbits around
either the sun (planet) or another planet (moon); here on Earth we call this a
year when the Earth orbits around the sun and a month when the moon goes
around the Earth once. Orbit is simply the path of the object.
What are Kepler’s Laws of Motion?
1st Law: This law states that the movement of planets is not in a perfect circle, but
in an elongated ellipse.
2nd Law: The closer the planet is to the sun, the faster the
planet will orbit the sun.
3rd Law: The longer the distance of a planet from the sun, the greater the time it
takes for the planet to complete a year (1 revolution).
What is the Law of Universal Gravitation? The Law of Universal Gravitation states that the
gravitational force between two objects depends on the distance between them
and their masses. Gravity will increase when mass increases or the distance
between objects decreases. Vice versa for decreasing gravity.
What are the two factors of the gravitational forces between two objects? Mass and Distance.
See above.
What is the reason that the moon orbits Earth, yet does not crash into Earth? The reason that the
moon does not crash into the Earth is because of inertia. The gravity of Earth
causes the moon to be pulled to Earth, yet the forward motion of the moon
keeps it in a circular orbit.
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