Planetary Attribute Albedo Radius Gravitational acceleration Mean distance from sun Surface pressure Symbol α R (km) g (m/s²) D (km) Po (kPa) Earth 0.29 6378 9.8 150 x 106 101 Mars 0.25 3395 3.7 228 x 106 0.6 (a) Calculate an appropriate value for shortwave solar radiation (SM) incident at the top of the Martian atmosphere (answer in W/m²). The corresponding value for Earth, SE = 1360 W/m². (b) Estimate the average surface temperature on Mars (answer in degrees Kelvin) using a suitable radiative energy balance. The greenhouse effect can be neglected for Mars. (c) Estimate the mass of the Martian atmosphere (answer in kg).

Planetary Attribute Albedo Radius Gravitational acceleration Mean distance from sun Surface pressure Symbol α R (km) g (m/s²) D (km) Po (kPa) Earth 0.29 6378 9.8 150 x 106 101 Mars 0.25 3395 3.7 228 x 106 0.6 (a) Calculate an appropriate value for shortwave solar radiation (SM) incident at the top of the Martian atmosphere (answer in W/m²). The corresponding value for Earth, SE = 1360 W/m². (b) Estimate the average surface temperature on Mars (answer in degrees Kelvin) using a suitable radiative energy balance. The greenhouse effect can be neglected for Mars. (c) Estimate the mass of the Martian atmosphere (answer in kg).