The earliest of the Big Five, the end-Ordovician or Ordovician-Silurian extinction events some 444 million years ago, are reckoned by many to be the second largest.
More than 80 of its supporters are reckoned to have been killed, 10,000 of them injured, twice as many homes destroyed, and more than 200,000 people displaced.
By as soon as December, the state's undocumented immigrants, who are reckoned to number anywhere from 500,000 to 1m, could start to get licences that will allow them to drive legally.
Recent findings lend strong support to the theory that a black hole lies at the center of the Milky Way and of many of the 100 billion other galaxies estimated to exist in the universe.
Some scientists are examining the potential for harvesting icebergs from Antarctica, which is estimated to have the biggest reserves of fresh water on the planet.
Though outsiders are generally barred from the region, casualties have been estimated in the thousands, with tens of thousands of civilians forced to flee their homes.
It is estimated that as many as one-third of Armenia "s population lives in Russia illegally, and that Armenia has no more than about two million residents."