In outer space, an object’s location has a huge impact on its temperature. The closer the object is to its star, the hotter it most likely is. Heat then plays a major role in what materials are present in that object’s atmosphere, if it has one. Lighter elements such as hydrogen and helium and much easier to take a gaseous state and create an atmosphere. So it came as a surprise when two different teams found much heavier elements in the atmosphere of comets that were relatively far away from the Sun. And one of those comets happened to be from another solar system.