--- title: "The solar system (age 11+)" description: "Describe the detailed structure of the solar system, including moons, asteroids, and comets, compare orbital periods and distances of the planets, and distinguish between planets, dwarf planets, and o" canonical: https://lightmysky.com/learn/science/the-solar-system-age-11-mt_33RrpbceZE source: https://lightmysky.com/learn/science/the-solar-system-age-11-mt_33RrpbceZE.md retrieved: 2026-11-12 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # The solar system (age 11+) Describe the detailed structure of the solar system, including moons, asteroids, and comets, compare orbital periods and distances of the planets, and distinguish between planets, dwarf planets, and other bodies Subject: Science · Area: Space Systems & Earth's History · Ages 11 to 12 Page: https://lightmysky.com/learn/science/the-solar-system-age-11-mt_33RrpbceZE ## Ready when they can - Identifies the eight planets in order from the Sun and matches each to a distinguishing fact - Describes the difference between a planet, a dwarf planet, an asteroid, and a comet - Explains that planets farther from the Sun on average have longer orbital periods because their paths are longer and their average orbital speeds are lower ## Lesson: The solar system (age 11+) From the Sun outward: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Mercury is smallest; Venus is hottest. Earth has liquid oceans; Mars has a reddish surface. Jupiter is largest; Saturn has bright, wide rings. Uranus spins almost on its side; Neptune is farthest from the Sun. Check each planet claim against these facts, then count the matches. A moon is a natural body orbiting a planet or another small world. A planet orbits the Sun and has enough gravity to become nearly round. It must also dominate its orbital neighborhood. This is called clearing the neighborhood. This does not mean an empty path. A dwarf planet is nearly round, orbits the Sun, and is not a moon, but has not cleared its neighborhood. Pluto and Ceres are dwarf planets; Ceres lies between Mars and Jupiter. Most asteroids are small and irregular. *(drawing: The numbers give orbital periods in Earth years. Read the value above each planet's bar. The planets are listed from the Sun outward.)* An orbital period is the time for one orbit. Planetary orbits are slightly stretched loops. Planets farther from the Sun on average have longer paths and lower average orbital speeds, so their years are longer. Mars takes about 1.9 Earth years; Neptune takes about 165. For objects orbiting the Sun, a longer period indicates a larger orbit overall. Distance changes along a stretched orbit, so a period cannot tell you where an object is today. Asteroids are mostly rocky or metallic bodies. Most orbit between Mars and Jupiter in the asteroid belt. Comets contain ice, dust, and rock. Near the Sun, ice can turn into gas and release dust, forming tails. A distant comet may have no visible tail. Some asteroids also release dust, so a tail alone is not a reliable way to distinguish these bodies. **Recap.** Planets, dwarf planets, moons, asteroids, and comets have different features. Among the planets, greater average distance from the Sun means a longer orbital period. *Lesson, questions, and flashcards written for this dataset.* ## Practice 8 questions on this page, each with its working shown. ## Needs first - [The solar system](https://lightmysky.com/learn/science/the-solar-system-mt_5l7iGkf1Tp) ## Opens up - [Why We Have Seasons](https://lightmysky.com/learn/science/why-we-have-seasons-mt_lFiDFPkVmH) - [Universal Gravitation](https://lightmysky.com/learn/science/universal-gravitation-mt_oLjz18CxDg) - [Finding Exoplanets](https://lightmysky.com/learn/science/finding-exoplanets-mt_UjuriPLVgT)