Final answer:
The crust, mantle, core, nebula, and solar system are terms describing Earth's layers and cosmic entities. The crust is the outer layer, the mantle lies beneath, and the core is the central part of Earth. Nebulae are gas and dust clouds, and the solar system is our Sun's planetary geology.
Step-by-step explanation:
The terms mantle, crust, nebula, core, and solar system are used to describe components of Earth and the larger universe. Here are their definitions:
- Crust: The outermost layer of a terrestrial planet, including Earth, primarily composed of silicon oxide and aluminum oxide. It is thinner under the oceans and thickest beneath mountains.
- Mantle: The layer of Earth beneath the crust, composed of silicate minerals. It is responsible for much of the tectonic activity due to mantle convection.
- Core: The central part of Earth, consisting of higher density materials such as iron and nickel, and generating Earth's magnetic field.
- Nebula: A cloud of gas and dust in space, which can be the birthplace of stars and planetary systems.
- Solar System: The collection of planets, moons, asteroids, comets, and other bodies orbiting our Sun, all of which formed from the solar nebula.
A solar nebula is believed to be the mother cloud from which our solar system formed. Astronomers suggest this because of the common motion of planetary bodies in one plane around the sun, and similar chemical compositions. The differences between terrestrial and giant planets include their size, composition, and distance from the sun.
Terrestrial planets are smaller, rockier, and closer to the sun, while giant planets are larger, mostly gaseous, and found in the outer solar system. The reason the Moon has many craters compared to Earth is due to Earth's atmosphere, which burns up small objects before impact, and geologic activity, which reshapes Earth's surface and erases evidence of past impacts.