Sun tanning However, it operates not by inducing direct DNA damage, but by producing reactive oxygen species which damage DNA indirectly. UVA (see above) induces a cosmetic tan but little extra melanin protection against sun damage, sun burn, or cancer. Ultraviolet B (UVB) radiation is in the wavelength range 280 to 320 nm. Much of this band is blocked by the Earth's ozone layer, but some penetrates. UVB: A person's natural skin color affects their reaction to exposure to the sun. An individual's natural skin color can vary from a dark brown to a nearly colorless pigmentation, which may appear white .
Atmospheric Chemistry Suite than the PFS spectrometer of Mars Express orbiter. Of particular interest to this astrobiology mission, is the detection and characterization of the atmospheric methane (), as it may be of geological or biological nature. Large differences in the abundances were measured between observations taken in 2003, 2006, and on 2014 NASA reported that the "Curiosity" rover detected a tenfold increase ('spike') in methane in the atmosphere in late 2013 and early 2014. This suggestes that the methane was locally concentrated and is probably seasonal. Because methane on Mars would quickly break down due to ultraviolet radiation from the Sun and