Short
Definition
Terrestrial planets are rocky planets with solid surfaces, composed mainly of
silicate rocks and metals. They are considered potentially habitable due to
their location within the habitable zone of their star, this means that they
are located at a distance from their star where the temperature is neither too
hot nor too cold for liquid water to exist.
Detailed Definition
Terrestrial planets include Earth, Venus, Mars, and Mercury and typically have
thin or no atmospheres, distinguishing them from gas giants. With relatively
high densities compared to gas giants, terrestrial planets tend to exhibit a
wide range of geological features, such as mountains, valleys, and impact
craters.
Additionally, their relatively high densities contribute to their stronger
gravitational pull, which affects not only their overall structure but also the
dynamics of their planetary systems. It is likely that there were more
terrestrial planets during the formation of our solar system, but they either
merged with each other or were destroyed. Their unique characteristics and potential for habitability make terrestrial
planets a subject of ongoing scientific study and appealing for potential
colonization by humans in the future.
Etymology
The term "terrestrial planets" originates from the Latin word
"terra," which means "earth" or "land." The word
"terrestrial" itself is derived from the Latin adjective
"terraeus," meaning "of the earth."
The word "planet" has its roots in ancient Greek. It comes from the
Greek term "planētēs," which means "wanderer" or
"wandering star."
Sample Sentence(s)
"It's
unclear what the dividing line is between a rocky planet and a terrestrial
planet."
Morbidelli, A., Lunine, J. I., O’Brien, D. P., Raymond, S. N., &
Walsh, K. J. (2012). Building Terrestrial Planets. Annual Review of Earth
and Planetary Sciences, 40(1), 251–275. https://doi.org/10.1146/annurev-earth-042711-105319
