Question

Which planet has extreme temperatures because it has no atmosphere? A) Earth C) Saturn B) Jupiter D) Mercury

Short answer

The answer is D) Mercury.

Step-by-step solution

Understanding Atmospheric Influence on Temperature

Planets with atmospheres can regulate temperature better than those without, as atmospheres can trap heat and distribute it across the surface. Extreme temperature variations typically indicate a lack of atmosphere.

Evaluating Earth and Saturn

Earth has a rich atmosphere that supports life by moderating temperature. Saturn, being a gas giant, not only has an atmosphere but an entire layer of gas surrounding it, ruling out extreme temperature variations due to lacking atmosphere.

Evaluating Jupiter

Jupiter is another gas giant like Saturn, with a thick atmosphere composed mostly of hydrogen and helium. It does not experience extreme temperature variations due to lack of atmosphere.

Evaluating Mercury

Mercury has virtually no atmosphere; it is exposed to the Sun's heat during the day and extremely cold at night. This absence of atmosphere leads to the planet experiencing extreme temperature variations, ranging from about -173°C at night to 427°C during the day.

Conclusion

Based on the analysis, Mercury is the planet with extreme temperatures due to the lack of atmosphere. Thus, it cannot retain heat when the Sun sets.

Key concepts

Atmosphere

An atmosphere is a layer of gases surrounding a planet. It plays a crucial role in moderating planetary temperatures. One of the main functions of an atmosphere is to act like a blanket, trapping heat from the Sun. This process is known as the greenhouse effect and is vital for maintaining stable temperatures. In addition to heat regulation, an atmosphere helps distribute energy around a planet. This can be through wind patterns or ocean currents (on planets with liquid water). Moreover, an atmosphere can protect a planet's surface from meteoroids and harmful solar radiation. Planets with thick atmospheres, like Earth and the gas giants, can better regulate thermal energy, leading to moderate temperature variations. In contrast, planets lacking a substantial atmosphere, such as Mercury, face extreme temps because there's little to no heat retention.

Planetary Temperature

Planetary temperature refers to the range of temperatures experienced on a planet's surface. These temperatures are influenced by a variety of factors like a planet's distance from the Sun, its atmosphere, and its rotation period. Planets closer to the Sun generally receive more heat, but temperature also depends on how well a planet can retain that heat. This is where an atmosphere becomes important, as it can help trap heat and keep a planet warmer during the colder periods. For instance, Mercury, which lacks a significant atmosphere, can only retain little heat. This results in it having stark contrasts between daytime and nighttime temperatures. During the day, it can reach scorching temperatures of up to 427°C. Conversely, at night, its surface plummets to a frigid -173°C due to the lack of heat retention.

Planetary Science

Planetary science is the study of planets, their moons, and planetary systems. It covers how they form, evolve, and what they are composed of. This field integrates aspects of astronomy, geology, atmospheric science, and physics. Understanding how atmospheres affect planetary climates is a key aspect of planetary science. The atmosphere—or lack thereof—can greatly impact surface temperatures, weather patterns, and even potential habitability. Researchers in planetary science use a combination of observational data, computer models, and experimental studies to understand different planetary environments. By studying atmospheres across the solar system, scientists can develop insights into Earth's climate and potential changes. Exploring planets like Mercury, which have extreme conditions, can also provide clues to the dynamics of planet-forming processes.

Mercury

Mercury is the closest planet to the Sun and has unique characteristics due to its proximity. It is a rocky planet with no significant atmosphere to speak of, which leads to its extreme temperature fluctuations. During the day, Mercury can reach temperatures as high as 427°C due to direct sunlight. However, when the Sun sets, temperatures can drop drastically to -173°C. The absence of a thick atmosphere prevents Mercury from retaining heat, unlike Earth, which uses its atmosphere like a thermal blanket. Mercury's surface is marked by craters and ridges, similar to our Moon. Its almost nonexistent atmosphere means it cannot protect itself from meteoroid impacts or buffer against solar wind. Mercury's study helps scientists understand how atmospheres form and evolve, highlighting the importance of an atmosphere in moderating a planet's surface conditions.