Grades 6-8 Notes & Discussion Topics
This page corresponds to the Learning Activities section of the Toolkit for Grade 6-8.
Here you'll find:
Discussion Questions & Answers
Theme: Astronomical (Celestial) Objects in the Day and Night Sky
The Sun is largest object in solar system.
- Discussion Question: If the Sun is the largest object in the solar system, why does the Sun look so small?
- Answer: Because it is so far away.
The sun gives us heat and light.
- Discussion Question: What does the Sun do for us?
- Answer: Supports all life on Earth through the process of photosynthesis. Provides us with heat and light. Powers the water cycle which creates our weather and climate. Provides us with seasonal cycles and even sleep cycles
- NOTE: Stars are suns. Our Sun is the star at the center of our solar system. The Sun is orbited by planets, asteroids, and comets. Astronomers have discovered that many other stars have planets too. If we were on a planet in another solar system, the Sun would look like just another star in our sky. The Sun is considered an average sized star.
The Moon is the Earth's only natural satellite.
- Discussion Question: Do we always see the same side of the Moon?
- Answer: We always see the same side of the Moon because it takes about the same amount of time for the Moon to rotate as it does to revolve around the Earth. The side we don't see is known as "the far side of the Moon."
Theme: Solar System
Overview of solar system: it has 1 star, 8 planets, and many small objects in it
- NOTE: The solar system contains the Sun, planets, dwarf planets, asteroids, comets, meteoroids (small debris traveling through the solar system), dust, and radiation. There are only eight planets. Since 1992, we have discovered hundreds of icy bodies like Pluto with tilted oval orbits past the orbit of Neptune. These bodies are called Kuiper belt objects. Pluto is one of the larger members and has been reclassified as a dwarf planet. There are currently 5 dwarf planets: Ceres, Pluto, Eris, Makemake, Haumea.
Planets revolve around stars.
- Discussion Question: What star does Earth orbit?
- Answer: The Sun
- Discussion Question: What is the shape of Earth's orbit around the Sun?
- Answer: Earth's orbit is an ellipse that is close to a circle with the Sun on one focus of the ellipse.
- NOTE: Planets orbit the Sun on slightly elliptical, or oval-shaped, paths. In addition, planets closer to the Sun complete their orbits faster than planets farther away; Mercury orbits the Sun every 88 Earth days, and Neptune orbits the Sun once every 164.89 Earth-years.
Characteristics/properties of different planets. How do we know the physical properties of a planet?
- NOTE: Question: What is the difference between a star and a planet? Answer: A star is a ball of very hot gas where nuclear fusion can occur and which produces the light that make stars shine. A planet, on the other hand, gets its light reflected from its companion star.
- NOTE: All planets are not made of the same material. Planets are separated into two categories: inner and outer planets. The inner planets are smaller and made of rock. The inner planets include the planets closest to the Sun: Mercury, Venus, Earth and Mars. The outer planets are often called gas giants because they are very large and made of gases. The outer planets include: Jupiter, Saturn Uranus and Neptune
Special objects such as Asteroids, Comets, Kuiper Belt objects, Oort Cloud, Dwarf Planets (such as Pluto)
- NOTE: Since 1992, we have discovered hundreds of icy bodies like Pluto with tilted oval orbits past the orbit of Neptune. These bodies are called Kuiper belt objects. Pluto is one of the larger members and has been reclassified as a dwarf planet. There are currently 5 dwarf planets (Ceres, Pluto, Eris, Haumea, Makemake)
- Discussion Question: What is a Comet?
- Answer: Comets travel though the solar system in irregular orbits from regions beyond the orbit of Neptune. A comet is a large ball of ice and rock. Comets can be seen as they approach the Sun because the Sun's heat melts a comet's ice to form glowing gases that stream out into a long tail. Comets look like bright streaks in the sky.
Theme: Earth/Moon/Sun Interactions
Rotation of the earth: evidence is day and night.
- Discussion Question: If the Earth is moving, why don't we feel it?
- Answer: We don't feel it because the Earth is rotating at approximately 1000 miles per hour. We don't "feel" that we are traveling at this speed because the Earth, our frame of reference, is traveling with us. The same is true of traveling in a car at a constant speed, unless you are looking out the window
The Sun and other celestial objects move across the sky.
- Discussion Question: The Sun, Moon, and stars are always in the same places in the sky.
- Answer: False. As the Earth rotates, the Sun, Moon and stars appear to move across the sky. They rise and set. Also, the Moon orbits the Earth once a month and the Earth orbits the Sun once a year, so the Moon and Sun pass through different parts of the sky.
Revolution of the earth: evidence are seasonal constellations
- NOTE: Ancient cultures observed seasonal movements of celestial objects and based their calendars on them. A year is based on the time required for the Earth to orbit the Sun once. A month is about the time required for the Moon to orbit the Earth once. A day is the time required for the Earth to rotate once on its axis.
- True or False: An eclipse of the Sun happens when the Moon comes between the Sun and the Earth.
- Answer: True. During a solar eclipse, the Moon does not come between the Sun and the Earth. The Moon's shadow falls on the Earth. Solar eclipses are rare. Because the Moon is so small compared to Earth, the shadow it casts on Earth's surface is very small. Only people in a limited area are able to see a total solar eclipse.
- NOTE: There are two kinds of eclipses: solar and lunar.
- Lunar Eclipse: Earth moves between the Sun and the moon, blocking part of the Sun's light from reaching the Moon. During this time, you will see the Earth's shadow on the Moon.'
- Solar Eclipse: The Moon moves between the Earth and the Sun. This causes part of the Sun's light to be blocked. The sky will get dark when this blockage occurs.
- A "Total" eclipse is when the Moon and the sun are in a perfect line. This occurrence is very rare.
Phases of the Moon
- NOTE: The Moon's phases are caused by two things: 1. The Moon revolving around the Earth. 2. The Moon reflecting sunlight towards the Earth. Half of the Moon is always lit, not just the portion we see: however, sometimes we only see a profile of the lit portion of the Moon. Certain phases of the Moon result depending on its orbit, and the Moon's orbit is responsible for the phase changes we see. Since we only see the lit portion of the Moon that is facing Earth, we see a Moon phase.
There are eighth phases that the Moon goes through and they always occur in the same order. The Sun's light seems to move from right to left across the surface of the Moon.
- The phases of the Moon are: 1. New Moon, 2. Waxing Crescent, 3. First Quarter, 4. Waxing Gibbous, 5. Full Moon, 6. Waning Gibbous, 7. Last Quarter, 8. Waning Crescent, and back to the New Moon.
- Discussion Question: Is the Sun closer to the Earth during the summer months than during the winter months?
- Answer: No. The Earth is not closer to the Sun in the summer.
- The seasons happen because the Earth's rotation is tilted compared to its orbit around the Sun. Summer happens for us when our part of the Earth is tilted toward the Sun, and winter happens when we are tilted away. In fact, the Earth is slightly farther away from the Sun when we are experiencing summer in the northern hemisphere. The tilt causes the Sun to reach different heights at different times of the year and to be up for longer periods of time than others. Parts of the Earth that have the Sun appear high in the sky experience summer and those that have the Sun low in the sky experience winter. Spring and fall occur when the sunlight is directly over the equator (in the middle) so for neither hemisphere the sun appears to be particularly high or low in the sky.
Modern 88 official constellations, Seasonal versus circumpolar, and some Basic Constellations
- Discussion Question: What are Constellations?
- Answer: Constellations are patches of sky that contain a characteristic pattern of stars.
- The patterns are often named after characters from ancient Greek and Roman mythology (although individual stars have mostly Arabic names). There are 88 official constellations. Common constellations visible from Milwaukee include the Big Dipper, Gemini, Orion, and Leo (to mention a few)
- Some basic constellations Always visible at Midwestern latitudes: Big Bear (contains Big Dipper), Little Bear, Cassiopeia Spring: Gemini, Leo; Summer: Cygnus, Summer Triangle; Fall: Pegasus, Andromeda; Winter: Orion, Taurus
- NOTE: Ancient people observed that the Sun, Moon, and planets always seem to move across the sky through a series of twelve constellations, knows as the zodiac. In particular, a person's zodiac sign was the name of one of the 12 constellations of the zodiac that the Sun was closest to at the time of the person's birth.
- In Milwaukee there are stars that we can see all year round. Some we can see include the stars of the Big Dipper, and Polaris the circumpolar North Star.
Sky maps and stargazing
- Discussion Question: How can you tell the difference between a star and a planet in the sky?
- Answer: The stars in the sky appear to be in fixed positions with respect to each other. They can seem like they are attached to an imaginary "celestial sphere" around the Earth. Planets move in complicated paths across the sky. They exhibit a behavior called "retrograde motion" where they appear to go backwards for a period of time relative to the background stars in the celestial sphere as they move in their orbit around the Sun. Also, planets almost never twinkle.
Theme: Life of a Star
How do stars live?
- Discussion Question: How do stars form?
- Answer: Stars are continually being formed and destroyed. Stars are formed, or born, in clouds of gas and dust in the interstellar medium. Gravity squeezes the mass of these "star nurseries" so that the centers become incredibly dense and hot. These extreme conditions allow hydrogen fusion to begin. The outward pressure from the fusion balances the inward force of gravity. The gas stops collapsing and a star is born.
Your visit will help you address the following targets and standards:
Wisconsin Model Academic Content Standards and WKCE Assessment Frameworks Taught in 7th Grade in MPS
- E.8.7 Describe the general structure of the solar system, galaxies, and the universe, explaining the nature of the evidence used to develop current models of the universe.
- (E 8.7.a) The sun as a star in our solar system
- (E 8.7.b) Different stars have different properties
- (E 8.7.d) Supporting evidence for current models of our solar system
- (E 8.7.e) Models that represent the solar system, galaxies and the universe
- E.8.8 Using past and current models of the structure of the solar system, explain the daily, monthly, yearly, and long term cycles of the Earth, citing evidence gained from personal observation as well as evidence used by scientists.
- (E.8.1) Systems, change, organization; forces that change/shape the earth
- (E 8.8.a) Objects in the solar system have regular and predictable orbits and motion
- (E 8.8b) Seasons are caused by the tilt of the Earth on its axis as it revolves around the sun
- (E 8.8.c) Rotation of the Earth on its axis causes day and night
- (E 8.8.d) Gravity's relationship to the solar system
MPS Learning Targets
- Modeling of solar system and universe
- Explain celestial cycles of day/night and seasons
5. Earth and Space Science
Illustrate and compare the basic features and structure of the earth; describe how forces change the earth's surface; identify factors that influence the history of the earth.
NOTE: When bringing 8th graders to the planetarium be sure to mention that you want the concepts of the Universe including the origin and evolution to be emphasized as these are tested in the WKCE.
Wisconsin Model Academic Content Standards and WKCE Assessment Frameworks Taught in 8th Grade in MPS
E. Earth and Space Science
Students in Wisconsin will demonstrate an understanding of the structure and systems of the earth and other bodies in the universe and their interactions. Big Ideas include the history and evolution in the universe, properties of Earth systems and universe systems.
- (E 10.3.c, E 10.5.a) Constancy, change, evolution, to explain the origin and evolution of the universe
- (E 10.5.a) Big Bang Theory
- (E 10.5.b) Expansion of the universe
MPS Learning Target
5. Earth and Space Science
Research and interpret scientific information about earth's history; use models to analyze the composition of the universe to explain its structure and how earth relates to the solar system.
- Solar system
- Celestial phenomena
- Space exploration
Science Process Skills
- Asking Questions
- Analyzing Data
- Reaching Conclusions
- Connecting relevance to students' world
Integration Learning Targets
- Follow oral directions
- Participate in group discussions
- Develop appropriate communication skills
- Write research paper
- Use coordinates to specify locations and to represent simple figures
- Models to scale
- Demonstrate self-control and the ability to follow directions
- Identify and compare stories from different cultures
- History of astronomical theories and space exploration
- Neutron star
- Astronomical unit
- Terrestrial planets
- Black hole
- Prograde motion
- Retrograde motion
- Spiral galaxy
- Leap year
- Gas giants
- Elliptical galaxy
- Irregular galaxy
- Open cluster
- Right ascension
- Globular cluster
- Celestial equator
- Asteroid belt
- Big Bang Theory
- Light year
- Cosmic background
- Refracting telescope
- Reflecting telescope
- Electromagnetic spectrum
- Apparent magnitude
- Solar system
- Absolute magnitude
- Orbital velocity
- Escape velocity
- H-R diagram
- Artificial satellite
- Main sequence
- Low Earth orbit
- White dwarf
- Red giant
- Period of revolution
- Space probe
- Space shuttle
- International Space Station
- Space junk