Astronomy Study Notes Essay

Submitted By mahenr13
Words: 290
Pages: 2

A planet that can support life must be geologically active primarily because volcanism produces outgassed water vapor which, in a sense, “rains down” on the surface of the planet creating oceans. A planet’s ability to be geologically active has much to do with its size because larger planets hold their heat longer than smaller planets and heat is required for geological activity, especially volcanism. Even though a planet may be able to outgas water vapor through active volcanoes, the surface of the planet may not be the correct temperature to ensure the water does not freeze or evaporate. On Earth, this is due in part to its distance from the Sun. Because Earth is not too close to the Sun, it does not encounter the runaway greenhouse effect where it perpetually heats (which would cause life to cease and water to vaporize). Instead, Earth is a comfortable distance from the Sun, which does heat the surface, but not to a temperature suitable to life, that is where the atmosphere comes into play.
The Earth’s atmosphere, specifically the greenhouse effect of our atmosphere plays a large role in Earth’s ability to harbor life. The greenhouse effect, traps the infrared light that the ground emits due to reflection of the Sun’s rays. This trapping of the light, which is a heat source, before it can return to space, warms our planet to a temperature acceptable to the flow of water and of human life. Our atmosphere also converts the ultraviolet and radiation light from…