The universe includes all space, matter, and energy.
The solar system is a collection of large and small bodies orbiting the sun.
It contains eight planets, which are generally larger than other bodies.
A planet is defined as a spherical body orbiting the sun.
The terrestrial planets are Mercury, Venus, Earth, and Mars.
They are rocky, dense, and relatively small.
The gas giant planets are Jupiter, Saturn, Uranus, and Neptune.
They feature thick, gaseous atmospheres, small, rocky cores, and ring systems of ice, rock, and dust.
A star is a large celestial body composed of gas and emitting light.
Most stars consist almost entirely of hydrogen and helium.
Astronomy Flashcards