Ultraviolet an Å is a unit of

Ultraviolet or UV radiation falls between x-rays and visible light. 1 It is easily absorbed by most materials and hard to detect. 4 It’s main natural source is from the sun, and it is also the common source that people encounter. Though only about 10% of the light that the sun produces is UV light and only about ? of this reaches the earth’s surface. The UV rays from the sun are what cause sunburns as they damage tissue. According to the Health Physics Society, “Artificial sources include tanning booths, black lights, curing lamps, germicidal lamps, mercury vapor lamps, halogen lights, high-intensity discharge lamps, fluorescent and incandescent sources, and some types of lasers.” UV rays can also be produced when an electric current is passed through vaporized mercury or other gases. UV rays have enough energy to break chemical bonds, which is called ionization. Ionization is the process of electrons breaking away from atoms or when a photon gains a negative or positive charge to form ions.This is useful for chemical processing but also results in damaged tissue, which could, if no precautions are taken, cause forms of skin cancer. UV waves can cause skin cancer but it has also been found that it can treat some skin conditions if treated with utmost care.There are also four main categories of UV rays. UVA, or near UV (315–400 nm), UVB, or middle UV (280–315 nm), UVC, or far UV (180–280 nm) and Extreme UV or Vacuum UV(1-100 nm). 1The EUVE is a NASA space-telescope that was launched June 7th, 1992, which operated until January 31, 2001. The EUVE’s purpose was to observe extreme UV waves, specifically waves between 70 and 760 Å (7-76 nm). 2 An Ångström, or an Å is a unit of measurement that equals 0.1 nanometres. 3 It used the UV rays it detected to create deep-space images and scans.4 It did this by recognizing the chemical compositions, densities, and temperatures of stars and objects. It specifically used UV rays to detects photospheric emissions from stars to develop the deep-space images. The EUVE was the first telescope to detect extragalactic objects, or objects outside of the milky way. “This spacecraft’s objective was to carry out a full-sky survey, and subsequently, a deep-survey and pointed observations. Science objectives included discovering and studying UV sources radiating in this spectral region, and analyzing effects of the interstellar medium on the radiation from these sources,” says NASA. 2The satellite has four telescopes with gold-plated and several filters. This combination is used to maximize the telescope’s sensitivity to detect faint sources of UV waves. Three of the telescopes had scanners that were pointed in the direction the satellite was spinning and the other, the Deep Survey/Spectrometer Telescope, was pointed away from the sun. 6 Scientists were unable to use the standard technology used with space-telescopes, such as lenses, filters, and transmission gratings,  as they absorbed EUV waves. They needed to reflect the euv rays without having any of the waves absorbed, so they invented a “grazing-incidence mirror”. A grazing-incidence mirror was developed so the EUV  light hits the mirror at a steep angle, which prevents the rays from being absorbed. “In which the light collecting surface does not directly face the source, but is instead positioned almost parallel to the incoming radiation,” says NASA scientists. 4