Grade 4 Science - Unit 2 Solar System Assessment

Vocabulary practice flashcards covering the key concepts of the solar system, including inner and outer planetary characteristics, planet orders, and orbital motion.

The Sun

The central body of the solar system around which all eight planets orbit.

Inner Planets

The group of planets closest to the Sun (Mercury, Venus, Earth, and Mars) characterized by a rocky surface, few moons, small size, and a short revolution.

Outer Planets

The group of planets farthest from the Sun (Jupiter, Saturn, Uranus, and Neptune) characterized by a gaseous surface, many moons, giant size, and a long revolution.

Gas Giants

The four large, gaseous outer planets of the solar system: Jupiter, Saturn, Uranus, and Neptune.

Terrestrial Planet

A planet that has a solid, rocky surface, which applies to Mercury, Venus, Earth, and Mars.

Mercury

The planet closest in distance to the Sun, known as the smallest rocky terrestrial planet with a very thin atmosphere.

Jupiter

The largest planet in the solar system, located fifth in distance from the Sun.

Revolution of the Earth

The continuous movement of the Earth orbiting in a pathway around the Sun.

Planetary Order by Distance from the Sun

The sequential order of the eight planets starting closest to the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Planetary Order by Size (Smallest to Largest)

The arrangement of the planets from least to greatest in size: Mercury, Mars, Venus, Earth, Neptune, Uranus, Saturn, and Jupiter.