81.   Ultraviolet radiation accounts for one-tenth of the energy reaching the Earth from the sun.

82.   Ultraviolet radiation in sunlight causes cancer.

83.   Ultraviolet radiation is implicated in the vast majority of non-melanoma skin cancers, like basal cell carcinoma and squamous cells carcinoma, according to the American Cancer Society.

84.   Ultraviolet radiation is blamed for a host of health problems, including skin cancer and cataracts.

85.   Ultraviolet radiation is most intense in the middle of a summer day when skies are clear.

86.   Until it does, however, fewer ozone molecules mean the atmosphere absorbs less ultraviolet radiation.

87.   Walker soon became interested in X-rays and ultraviolet radiation from the sun, and he eventually collaborated with other scientists to fire the multilayer mirrors into space.

88.   When cloud cover varies widely from one year to the next, the ultraviolet radiation that people and other organisms are exposed to also varies.

89.   While ozone in the stratosphere blocks harmful ultraviolet radiation, lower down in the troposphere it also acts as a powerful greenhouse gas.

90.   Without ozone, this layer of the atmosphere does not absorb the energy arriving from the sun as ultraviolet radiation, making the thin air even cooler.