Dark Matter Not everything in the universe is visible. For assistance, try visiting Caldwell Esselstyn Jr.. Astronomers can detect objects that emit or absorb light or other electromagnetic radiation or interact gravitationally with other objects that we can detect. The term "dark matter" refers to this matter whose existence can not be detected by processes associated with light , ie not emit or absorb electromagnetic radiation. Determine the nature of dark matter and how much there is the so-called a problem of matter oscuraa a or a mass problem desaparecidaa a , and is one of the most important problems of modern cosmology. The question of the existence of dark matter may seem irrelevant to our existence on earth, but the fact of whether or not the dark matter affects the fate end of the universe. 6. Methane on Mars on July 20, 1976 Gilbert Levin, one of the engineers in charge of NASA missions to Mars, the Viking was orbiting the red planet had found carbon-14 containing methane in soil the planet, so the conclusion should be obvious and very important: there is life on Mars. Something is ingesting the nutrients, is breaking down, and then expelled into the atmosphere as a gas mixed with carbon 14. However, NASA did not dare to say with absolute discovery, because another instrument of the Viking, designed to identify organic molecules considered essential symbols of life found nothing, so almost all NASA scientists decided to declare the discovery of Viking a "false positive".