7th grade · Science · Unit 7 of 18
Our Solar System
Planets, moons and the asteroid belt
What your child practices
The planets in order, rocky versus giant planets, reading a table of planet data, moons, dwarf planets, comets and the asteroid belt.
Texas Essential Knowledge and Skills (TEKS) teks student expectation: 7.9(A) · the Sun, planets, moons and asteroid belt
How we explain it
Children can open this short lesson before they practice.
- The planets from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
- The first four are small rocky planets; the outer four are giant planets.
- The asteroid belt lies between Mars and Jupiter. Comets are icy and grow tails near the Sun.
Example: Is Mars a rocky planet or a giant planet? Mars is one of the first four planets. The inner four are rocky. Answer: rocky
Our Solar System in Texas
In the Texas Essential Knowledge and Skills (TEKS), this is unit 7 of 18 in 7th grade Science, after Heat & Particles and before Natural Selection.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Source: Texas Education Agency (TEA)
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
Put these in order, starting with the one closest to the Sun.
- Earth
- Mercury
- Venus
- Saturn
- Neptune
Mercury → Venus → Earth → Saturn → Neptune
Hint: Try: My Very Educated Mother Just Served Us Nachos (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune). The asteroid belt lies between Mars and Jupiter.
Question 2
Which planet in the table is the largest?
Planet data Planet Diameter (km) Distance from Sun (AU) Year (Earth years) Venus 12,104 0.7 0.62 Earth 12,756 1.0 1 Saturn 120,536 9.6 29.5 Uranus 51,118 19.2 84 - Uranus
- Earth
- Saturn
- Venus
Saturn
Hint: Compare the diameters. The biggest number is the widest planet.
Question 3
Which planet is closest to the Sun?
- Mercury
- Venus
- Earth
- Mars
Mercury
Hint: It's the smallest planet and it zips around the Sun in just 88 days.
Question 4
Which is the largest moon in the solar system?
- Phobos, a moon of Mars
- Titan, a moon of Saturn
- Ganymede, a moon of Jupiter
- Earth's Moon
Ganymede, a moon of Jupiter
Hint: The largest planet also has the largest moon. It's even bigger than the planet Mercury.
Question 5
Which planet is the largest?
🟠- Saturn
- Neptune
- Earth
- Jupiter
Jupiter
Hint: This giant is so big that more than 1000 Earths could fit inside it.
Question 6
Which planet is the hottest, because its thick atmosphere traps heat?
🌡️- Mercury
- Mars
- Venus
- Jupiter
Venus
Hint: Mercury is closer to the Sun, but Venus's thick carbon dioxide atmosphere traps heat like a blanket.