A system of millions or billions of stars, together with gas and dust, held together by gravitational attraction is called what?

A system of millions or billions of stars, together with gas and dust, held together by gravitational attraction is called what?

• A. Galaxy
• B. Lunar
• C. Gravitational forces
• D. Solar system

Answer: (A)

A galaxy is the huge assembly of millions to billions of stars, along with gas and dust, bound together by gravity. This gravity holds all that mass in one structure and gives galaxies their recognizable shapes, like spirals or ellipticals, with stars and interstellar material spread throughout. Our Milky Way is an example. In contrast, a solar system is just planets and other bodies orbiting a single star; the Moon-related term refers to the Moon itself, not a whole system; and gravitational forces describe the pull between masses, not a bound collection of objects.

A galaxy is the huge assembly of millions to billions of stars, along with gas and dust, bound together by gravity. This gravity holds all that mass in one structure and gives galaxies their recognizable shapes, like spirals or ellipticals, with stars and interstellar material spread throughout. Our Milky Way is an example. In contrast, a solar system is just planets and other bodies orbiting a single star; the Moon-related term refers to the Moon itself, not a whole system; and gravitational forces describe the pull between masses, not a bound collection of objects.