For example, early explorers expected to find a massive southern continent to balance the large northern land masses, and that continent was always placed in parts of the world that had not yet been explored by Westerners. Finally, there was no more unexplored space for it to occupy, and the theory was abandoned.
Interstellar material consists of gases and dust particles ejected from exploding stars.
Occasionally, molecules may react in interesting ways as their energy levels are raised by this radiation. Astronomers have now identified about fifty kinds of interstellar molecules, including ice, ammonia, cyanide, acetylene, formic acid, methane, methanol, ethanol, and even more complex hydrocarbons. There is no concentrated witches brew of these components, because they are scattered in a near vacuum. But organic molecules could be attracted to interstellar dust grains and accumulate in concentrated mixtures on their surfaces, probably in ices. The asteroid 5145 Pholus is extremely red, probably because it is coated with organic tars.