Science (8th Grade)
Movement in Space (Grade 8) — Astronomy: Motion of Celestial Objects
What must an object do to be officially classified as a "planet"?
Orbit a larger planet and reflect sunlight.
Produce a glowing tail as it approaches the sun.
Orbit the sun, be rounded by its own gravity, and clear its orbit of debris.
Remain stationary in the night sky relative to the stars.