Unit Review - Earth's Place in the Universe
Grade 6 Science Unit Review
Learning Objectives
Describe Earth's position within the solar system, galaxy, and universe, and explain why Earth is uniquely suited to support life
Explain that Earth's 23.5-degree axial tilt causes seasons by changing sunlight angle and daylight hours, and identify solstices and equinoxes
Identify and sequence the eight phases of the Moon and explain that phases are caused by the Moon's changing position relative to Earth and the Sun
Describe how the Moon causes ocean tides and compare solar and lunar eclipses
Describe notable moons of the solar system and explain tidal locking
Introduction
~1 minutesUnit Review: Earth's Place in the Universe
This review covers everything we learned about the Earth-Sun-Moon system. Use it to prepare for your unit assessment.
Review: Cosmic Address & Solar System
~5 minutesTopic 1: Our Cosmic Address & the Solar System
Your Cosmic Address (small to large): Earth → Solar System → Milky Way Galaxy → Local Group → Observable Universe
The Solar System:
• The Sun contains 99.8% of all mass in our solar system
• 8 planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
• Terrestrial (Rocky): Mercury, Venus, Earth, Mars, small, dense, solid surfaces
• Gas Giants: Jupiter, Saturn, large, no solid surface, hydrogen/helium
• Ice Giants: Uranus, Neptune, icy materials, smaller atmospheres
The Goldilocks Zone (Habitable Zone):
• The region around a star where liquid water can exist on a planet's surface
• Earth supports life because of: liquid water, breathable atmosphere (78% N2, 21% O2), protective magnetic field, and right size/gravity
Review: Seasons & Earth's Tilt
~5 minutesTopic 2: Seasons & Earth's Axial Tilt
MYTH BUSTED: Seasons are NOT caused by Earth's distance from the Sun. Earth is actually closest to the Sun in January!
The Real Cause: Earth's 23.5° axial tilt creates a double effect: 1. Changes the angle of sunlight (direct = concentrated = warmer; angled = spread out = cooler) 2. Changes the number of daylight hours
The Four Key Positions:
• Summer Solstice (~June 21): Longest day, North tilts toward Sun, ~14.5 hrs daylight in NC
• Fall Equinox (~Sept 22): Day ≈ night (~12 hrs), fall begins
• Winter Solstice (~Dec 21): Shortest day, North tilts away, ~9.5 hrs daylight in NC
• Spring Equinox (~March 20): Day ≈ night (~12 hrs), spring begins
Opposite Hemispheres: When it's summer in the Northern Hemisphere, it's winter in the Southern Hemisphere.
Review: Moon Phases
~5 minutesTopic 3: Moon Phases
Key Facts:
• The Moon does NOT produce its own light. It reflects sunlight
• Half the Moon is ALWAYS lit by the Sun
• Phases are caused by the Moon's changing position relative to Earth and the Sun, NOT by Earth's shadow
The Eight Phases (in order): 1. New Moon (completely dark) 2. Waxing Crescent (right sliver) 3. First Quarter (right half) 4. Waxing Gibbous (mostly lit, right) 5. Full Moon (completely lit) 6. Waning Gibbous (mostly lit, left) 7. Third Quarter (left half) 8. Waning Crescent (left sliver)
Memory trick: D-O-C: D shape = waxing, O = full, C shape = waning Waxing = getting bigger; Waning = getting smaller
Review: Tides & Eclipses
~4 minutesTopic 4: Tides & Eclipses
Ocean Tides:
• Caused by the Moon's (and Sun's) gravitational pull on Earth's oceans
• Two bulges create 2 high tides and 2 low tides per day
• Spring tides (extreme): New Moon & Full Moon, forces aligned
• Neap tides (moderate): Quarter Moons, forces at right angles
Eclipses:
| Feature | Solar Eclipse | Lunar Eclipse |
|---|---|---|
| What blocks light? | Moon blocks Sun | Earth blocks sunlight to Moon |
| Moon phase | New Moon | Full Moon |
| Eye safety | REQUIRES protection | Safe to view |
| Duration | Minutes | Hours |
Review: Moons of the Solar System
~3 minutesTopic 5: Moons of Our Solar System
Moon counts: Mercury (0), Venus (0), Earth (1), Mars (2), Jupiter (97), Saturn (274), Uranus (29), Neptune (16)
Giant planets have many moons because of their strong gravity.
Remarkable moons:
• Io (Jupiter): extremely active volcanoes
• Europa (Jupiter): icy crust, evidence for subsurface ocean
• Ganymede (Jupiter): largest moon in the Solar System
• Titan (Saturn): thick atmosphere, liquid methane lakes
• Enceladus (Saturn): ice geysers
Tidal locking: The Moon rotates once per orbit, keeping the same face toward Earth. The far side is NOT always dark. It gets sunlight too.
Unit Assessment
~22 minutesIn order from smallest to largest, your cosmic address would be:
About what percentage of our solar system's mass is contained in the Sun?
Which statement correctly describes a difference between rocky planets and gas giants?
What is the 'Goldilocks Zone' (habitable zone)?
Which of the following are reasons why Earth can support life? (Select ALL that apply)
Select all that apply.
What is the PRIMARY cause of Earth's seasons?
Earth is closest to the Sun during summer in the Northern Hemisphere.
Summer is warmer than winter due to TWO factors. What are they?
When it is winter in North Carolina, what season is it in Australia?
Match each event with its approximate date:
Earth's axis is tilted at ___1___ degrees from vertical. One complete rotation takes ___2___ hours, and one complete revolution around the Sun takes about ___3___ days.
What causes the phases of the Moon?
The Moon produces its own light.
What fraction of the Moon is ALWAYS lit by the Sun?
Put the Moon phases in the correct order, starting with New Moon:
[Unsupported question type: ordering]
Which statements about Moon phases are TRUE? (Select ALL that apply)
Select all that apply.
What causes ocean tides?
Spring tides (the highest high tides) occur during which Moon phases?
During which Moon phase does a solar eclipse occur?
Match each eclipse type with its characteristics:
Why don't eclipses happen every month?
Which definition best matches a moon (natural satellite)?
Which planets have ZERO known moons? (Select all that apply)
Select all that apply.
We see only one face of the Moon because the Moon does not rotate.
Match each remarkable moon with its key feature:
Place the planets in order from CLOSEST to the Sun to FARTHEST:
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Match each planet with its correct classification:
Venus is HOTTER than Mercury even though Mercury is closer to the Sun. Why?
Match each tide type with when it occurs:
Put these events in the correct order for ONE year in the Northern Hemisphere, starting with Spring:
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