How will the Odyssey probe detect water on Mars if its only beneath the crust?
Joey Cranbrook Middle School Bloomfield Hills, MI ANSWER: Cosmic rays emitted from the Sun strike the surface of Mars transferring large amounts of energy to the atoms they hit. These atoms release neutrons from their nucleus, which then strike other atoms. The energy transferred to the atoms by neutrons is emitted in the form of high-energy electromagnetic waves called gamma rays. The wavelength of energy emitted from a given atom is dependant on the type of element. Mars Odyssey’s Gamma Ray Spectrometer (GRS) is able to detect the region of gamma rays in the electromagnetic spectrum. The wavelength detected identifies the type of element and the intensity of the signal tells the elements abundance. Water is composed of hydrogen and oxygen (H2O). Oxygen is very common in minerals that make up the surface of Mars, however Hydrogen is not. When we identify hydrogen with the Gamma Ray Spectrometer most often it should be found bonded with oxygen to form water. Links: http://mars.jpl.nasa
