... eventually come together in a large gaseous region, it is given the sinister title of a dark molecular cloud because its chief component, molecular hydrogen, is either difficult or impossible to detect. Instead researchers often try to identify...
... for the KPg extinction event, but that a giant molecular cloud passing through the solar system led to an environmental catastrophe... colleagues also point out that an encounter with a dark cloud perturbs the orbit of asteroids and comets through its...