Science term 1
Pre-Knowledge & Solar System Basics
Q: How many planets are there in the Solar System?
A: 8
Q: Which planet was downgraded to a dwarf planet?
A: Pluto
Q: What is at the centre of the Solar System?
A: The Sun
Q: What phase of the Moon is it when you can see the entire Moon?
A: Full Moon
Q: What causes the different seasons on Earth?
A: The tilt of Earth’s axis as it orbits the Sun (not distance from the Sun)
Q: How many main phases of the Moon are there?
A: 8 (new, waxing crescent, first quarter, waxing gibbous, full, waning gibbous, last quarter, waning crescent)
Q: What do you call the course/path the planets take around the Sun?
A: Orbit
Q: What keeps the Moon close to the Earth?
A: Gravity
Q: Is it the same season in the Northern and Southern Hemispheres at the same time?
A: No (opposite seasons)
Q: How long does it take for Earth to orbit the Sun once?
A: 365.25 days (1 year)
Q: How long does it take for the Moon to orbit Earth once?
A: About 28 days (lunar month)
Q: What is gravity?
A: The force by which a planet or body draws objects toward its centre; stronger with greater mass.
Q: Which planet has the most gravity relative to Earth? (from table examples)
A: Jupiter (strongest surface gravity among listed)
Q: Which planet has the least gravity relative to Earth? (from table examples)
A: Mercury or Mars (both ~0.38 Earth gravity)
Solar System Structure & Planets
Q: What are stars primarily made of?
A: Hydrogen and helium (massive balls of hot gas)
Q: Name the 4 types of stars (common classification).
A: (Accept any reasonable: e.g., main sequence, red giants, white dwarfs, supergiants — booklet asks for 4 types)
Q: Which is the smallest planet?
A: Mercury
Q: Why is Mercury not the hottest planet despite being closest to the Sun?
A: It has almost no atmosphere to trap heat (quickly loses heat at night)
Q: Which planet is the brightest natural object in the sky after the Sun/Moon?
A: Venus (due to thick reflective clouds)
Q: Which is the only planet known to have liquid water and life?
A: Earth
Q: Which planet is known as the Red Planet?
A: Mars
Q: Which planet has the Great Red Spot (a storm raging for over 300 years)?
A: Jupiter
Q: Which planet has the most famous and visible rings?
A: Saturn
Q: Which planet has an extreme axial tilt of about 98 degrees, causing 42 years of daylight/darkness at poles?
A: Uranus
Q: Which is the furthest planet from the Sun?
A: Neptune
Models of the Solar System
Q: What is a model in science?
A: A representation of a person, thing, or proposed process, typically smaller than the original
Q: Name the two main historical categories of Solar System models.
A: Geocentric and Heliocentric
Q: Who produced the first geocentric model in the 4th century BC?
A: Plato (later refined by Ptolemy)
Q: What problem did retrograde motion cause for the geocentric model?
A: Planets appear to move backwards (retrograde) — Ptolemy used epicycles to explain it
Q: Who proposed the first heliocentric model around 250 BC?
A: Aristarchus (Sun at centre)
Q: Who revived heliocentric model in the 1500s with better math/observations?
A: Copernicus
Q: Who provided key telescope evidence (e.g., Jupiter’s moons, Venus phases) for heliocentric model?
A: Galileo
Q: What did Galileo observe on the Moon?
A: Mountains, valleys, craters (not perfect/smooth)
Q: What did Galileo discover around Jupiter?
A: Moons orbiting Jupiter (not everything orbits Earth)
Q: What did Galileo observe about Venus?
A: Phases (like Moon) — proves it orbits the Sun
Q: What did Galileo observe about the Milky Way?
A: Made of millions of tiny stars (universe much larger)
Seasons
Q: What misconception causes people to think seasons are due to Earth’s distance from the Sun?
A: False — orbit is nearly circular; tilt causes seasons
Q: When is summer in Brisbane (Southern Hemisphere)?
A: When Southern Hemisphere tilted towards the Sun → more direct sunlight, hotter, longer days
Q: What is an equinox?
A: Days and nights approximately equal length (March & September)
Q: What is a solstice?
A: Longest/shortest day (June & December in Southern Hemisphere)
Q: How many seasons do mid-latitude places (e.g., Hobart, Melbourne) usually have?
A: 4 distinct seasons
Q: How many seasons do tropical places near equator (e.g., Singapore, Darwin) have?
A: Usually 2 (wet/dry) — tilt has little effect on temperature
Q: How many seasons do Arctic places (e.g., Longyearbyen) experience?
A: Effectively 2 (continuous daylight or darkness periods)
Tides & Moon
Q: How long is one full lunar cycle?
A: About 28 days
Q: What is waxing vs waning Moon?
A: Waxing = growing lit portion; Waning = shrinking lit portion
Q: What causes tides on Earth?
A: Gravitational pull of the Moon (and Sun) on Earth’s oceans
Q: When do Spring tides occur? (alignment & effect)
A: Sun, Earth, Moon in straight line (full or new moon) → higher high tides, lower low tides
Q: When do Neap tides occur? (alignment & effect)
A: Sun, Earth, Moon at right angles (first/last quarter) → weaker tides, smaller range
Q: How many high and low tides usually occur per day?
A: 2 high and 2 low (semi-diurnal in most places)
Eclipses
Q: Draw/ describe alignment for a solar eclipse.
A: Moon between Sun and Earth (new moon phase); Moon blocks Sun from parts of Earth
Q: Draw/ describe alignment for a lunar eclipse.
A: Earth between Sun and Moon (full moon phase); Earth’s shadow darkens Moon
Q: What is the umbra?
A: Dark central part of shadow (total eclipse)
Q: What is the penumbra?
A: Lighter outer part of shadow (partial eclipse)
Q: Why are total solar eclipses rare?
A: Moon’s shadow is small; alignment must be precise
Q: Why must you never look directly at a solar eclipse?
A: Can cause permanent eye damage (even partial)
First Nations & Cultural Astronomy
Q: How long have First Nations Australians been observing the sky?
A: At least 65,000 years (oldest continuous astronomers)
Q: How did First Nations use Sun, Moon, stars?
A: Timekeeping, navigation, seasonal calendars, ceremonies, harvesting, cultural burning
Q: Who was Wang Zhenyi?
A: 18th-century Chinese astronomer who modelled eclipses and challenged superstitions