Mars' orbit: semi-major axis a=1.52 AU, eccentricity e=0.0934, obliquity=25.19 degrees. Albedo = 0.15

Puzzler 1: What is the subsolar heat flux (W m²) at (a) aphelion~N.summer and (b) perihelion~S. summer?

Distance from the Sun at aphelion = a (1+e) = 1.52 x 1.0934 = 1.66 AU

Distance from the Sun at perihelion = a (1-e) = 1.52 x 0.9066 = 1.38 AU

So, the subsolar (meaning at the point directly under the Sun - the Sun is straight overhead - the flux is perpendicular to the surface) point receives 1368 x (1-A)/ (distance)² = 1163 / (distance)² Watts m²

(a) at aphelion this is 422 Watts m²

(b) at perihelion this is 611 Watts m²