Absence of atmosphere would cause surface temperatures to be?

• A. More stable temperatures.
• B. Extreme hot on day and cold at night.
• C. Uniformly hot.
• D. Uniformly cold.

Answer: (B)

Without an atmosphere, the surface is heated only by direct solar energy and loses heat mainly by radiation to space, with no atmospheric blanket to trap heat or redistribute it. During the day, there’s nothing to absorb or scatter the sunlight beyond the surface itself, so temperatures can rise very high. At night, the surface radiates heat away and there’s no atmosphere to slow the cooling or supply warmth from elsewhere, so temperatures fall rapidly. This creates a large diurnal temperature range—extremely hot in the sun, extremely cold in the dark. On airless bodies like the Moon, you can see these dramatic day–night swings.