Potentially Hazardous Asteroids (PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time. On April 16, 2017 there were 11 potentially hazardous asteroids.
Radiation therapy is often delivered from a machine outside the body. One of the most common side effects is a skin condition called radiation dermatitis, which can range from a mild, red rash (erythema) and itchy, peeling or flaking skin (dry desquamation) to a more severe reaction with blisters and wet, peeling skin (moist desquamation).
UV Radiation. UV radiation comes from the sun and from tanning beds. UV radiation damages our skin and adversely affects our immune system. As previously mentioned, one blistering sunburn increases your risk of developing melanoma, which is a very dangerous and lethal skin cancer.