It has a 58-day period of rotation. Temperatures on its surface rise to 700 F. during its midday. Again Venus provides a hopeless environment for chlorophyll. The surface of Mars has temperatures which rise to 50 F. in the summertime shortly after noon, but at the same place drop to - 190 F. during its night time. Percival Lowell and others wished and hoped that Mars would provide a climate amenable to intelligent life, but the hopes of his followers were dashed by photos transmitted by Mariner 4 in 1964.
Radiation varies according to the principle of the inverse of the square of the distance.
This distance, according to our estimate, would provide freezing temperatures, ice, icebergs, blizzards and icy slush at the equator in oceanic regions. Terrestrial regions would be colder yet. Such is the outer limit where chlorophyll could function and flourish on our planet, given the level of the Sun's radiation. At terrestrial regions, temperatures would be even higher. Again, chlorophyll would have an environment where it could not function.