Terrestrial Planets: Venus, Earth, and Mars

Terrestrial Planets

Small, rocky planets with relatively thin or no atmosphere, few moons, and made from heavy elements (rock and metal). Examples include Mercury, Venus, Earth, Mars, and the Earth's Moon.

Craters

Depressions on the surface of planets and moons created by impacts from planetesimals; can vary in size and often overlap.

Heavy Bombardment

A period shortly after the formation of the planets marked by a high frequency of impacts from planetesimals, ending about 4 billion years ago.

Mares

Smooth, dark plains on the Moon created by ancient volcanic activity; regions where craters are sparse.

Volcanism

The geological process by which molten rock makes its way to the surface, leading to the formation of features like mountains and lava flows.

Seismometer

An instrument used to detect and measure seismic activity, allowing scientists to probe the interior structure of planets.

Atmospheric pressure on Venus

92 bar; a significant factor influencing the planet's surface conditions and exploration.

Olympus Mons

The largest volcano in the solar system, located on Mars, indicative of the planet's volcanic history.

Erosion

The process by which materials are worn away and removed from the Earth's surface by wind, water, or ice.

Plate Tectonics

The theory that describes the large-scale movements of the Earth's lithosphere, which is broken into tectonic plates; this phenomenon does not occur on other terrestrial planets.