Albedo their reflectivities. Fresh 'black' ice exhibits Fresnel reflection. Snow on top of this sea ice increases the albedo to 0.9. Cloud albedo has substantial influence over atmospheric temperatures. Different types of clouds exhibit different reflectivity, theoretically ranging in albedo from a minimum of near 0 to a maximum approaching 0.8. "On any given day, about half of Earth is covered by clouds, which reflect more sunlight than land and water. Clouds keep Earth cool by reflecting sunlight, but they can also serve as blankets to trap warmth." Albedo and climate in some areas are affected by artificial clouds, such as
Dynamic Albedo of Neutrons Dynamic Albedo of Neutrons The Dynamic Albedo of Neutrons (DAN) instrument is an experiment mounted on the Mars Science Laboratory "Curiosity" rover. It is a pulsed sealed-tube neutron source and detector used to measure hydrogen or ice and water at or near the Martian surface. DAN was provided by the Russian Federal Space Agency, funded by Russia and is under the leadership of Principal Investigator Igor Mitrofanov. On August 18, 2012 (sol ), DAN was turned on, marking the success of a Russian-American collaboration on the surface of Mars and the first working Russian science instrument on the Martian surface