Blast into 2025: Conquer the Astronomy Challenge – Your Cosmic Adventure Awaits!

The correct choice is the lack of atmosphere. Mercury's surface experiences extreme temperature fluctuations ranging from about -173 degrees Celsius (-280 degrees Fahrenheit) at night to 427 degrees Celsius (800 degrees Fahrenheit) during the day. This dramatic temperature change occurs because Mercury has a very thin atmosphere, composed mostly of oxygen, sodium, hydrogen, helium, and potassium. This minimal atmospheric composition is insufficient to retain heat, allowing daytime temperatures to soar while nighttime temperatures plummet as the sun sets.

In contrast, other celestial bodies with thicker atmospheres, such as Earth or Venus, experience milder temperature variations due to the greenhouse effect and the ability of their atmospheres to store heat. The high solar radiation that Mercury receives does contribute to high daytime temperatures, but it is the lack of a significant atmosphere that leads to the inability to moderate these temperatures during the planet's night cycle. Geological activity is minimal on Mercury, and proximity to Jupiter does not influence the surface temperature on Mercury directly. Thus, the absence of a substantial atmosphere is the primary reason for the drastic fluctuations in surface temperature.