Which term refers to a vast system of stars, dust, and gas bound by gravity, including our solar system?

Which term refers to a vast system of stars, dust, and gas bound by gravity, including our solar system?

• A. Sun
• B. Moon
• C. Planet
• D. Galaxy

Answer: (D)

A galaxy is a vast collection of stars, gas, and dust held together by gravity, and our solar system belongs to one. The Sun is just a single star, while the Moon is a natural satellite of Earth, and a planet is a single world that orbits a star. The description points to a large, gravitationally bound system that contains many stars, plus the material between them, which is exactly what a galaxy is. Our Sun sits inside the Milky Way galaxy, illustrating how a solar system is part of a much larger cosmic structure.

A galaxy is a vast collection of stars, gas, and dust held together by gravity, and our solar system belongs to one. The Sun is just a single star, while the Moon is a natural satellite of Earth, and a planet is a single world that orbits a star. The description points to a large, gravitationally bound system that contains many stars, plus the material between them, which is exactly what a galaxy is. Our Sun sits inside the Milky Way galaxy, illustrating how a solar system is part of a much larger cosmic structure.