Pic taken from nasa showing the light emitted when comet shoemaker impact Jupiter in July 1994. Data from the light will give more information about the elements found in Jupiter.Astronomers use diffraction grating to calculate the wavelength of light emitted by gases from outerspace. The wavelength of light will make identification of the element that produced it. In the first order the angular separation of bright lines are very small and therefore difficult to measure . Measuring angles at higher orders are easier because the bright lines has greater angular separation. At higher orders there are some disadvantages like lower intensity of the bright lines and overlapping of lines from the adjacent order may make identification of the particular wavelength of light difficult. Viewing first order bright lines does not have overlapping from the second order .
