Rosetta StoneFor thousands of years, the Egyptian civilization used a written language called hieroglyphics. This language was used from ancient times throughout the last several centuries B.C., when the Greeks under Alexander the Great conquered Egypt and introduced the Greek language. Then, around 50 B.C., the Roman Empire expanded into Egypt and the hieroglyphics language was abandoned in favor of Greek and Latin.
Sadly, within a hundred years of the Romans taking over Egypt, no one used or even understood hieroglyphics. None of the scholars at the time recorded any information on how to translate the language, so from that point on no one could read any of the Egyptian writings written in hieroglyphics. This was a huge obstacle for anyone wanting to study Egyptian history and culture.
Hieroglyphics remained a mystery for hundreds of years, even though many people tried to translate the language. It might still be a mystery if not for a chance discovery by some French soldiers who were fighting in Egypt. While working on constructing a fortress near Rosetta, a small city near Alexandria, a soldier named Pierre-Francois Bouchard found a flat block of black basalt about 4 feet long, 2 feet wide, and 1 foot thick. This block had three sections of writing on it--one in hieroglyphics, one in another language called Demotic which was another language used in Egypt, and one in Greek. This stone is known as the Rosetta Stone.
When scholars began studying the stone, they quickly realized that it contained one message written in three languages. They translated the Greek, and found that it was a decree praising the king of Egypt (Ptolemy V). Once they had the meaning of the message, they began to work on translating the other two languages. An English physicist named Thomas Young made the first key discovery when he showed that the signatures within the message (called cartouches) could be translated into the names of known rulers (Ptolemy and Alexander). Shortly after this, a French historian named Jean-Francois Champollion went on to completely translate the Rosetta Stone's hieroglyphics, opening the ancient Egyptian language to scholars and allowing them to read all the writings left behind by the Egyptians for the first time.
The Rosetta Stone provided a 'key' that was essential for our decipherment of hieroglyphics, and today we often hear something compared to the Rosetta Stone if it provides a way to decipher something that would otherwise be very difficult to understand. It is for this reason that the newest comet mission, Rosetta, was named after this famous stone. Hopefully, the Rosetta mission's findings will provide a key to the origin of comets and thus the origin of the solar system.