We've had a good run of it. In the 500,000 years Homo sapiens has roamed the land we've built cities, created complex languages, and sent robotic scouts to other planets. It's difficult to imagine it all coming to an end. Yet 99 percent of all species that ever lived have gone extinct, including every one of our hominid ancestors. In 1983, British cosmologist Brandon Carter framed the "Doomsday argument," a statistical way to judge when we might join them.

Here are some interesting facts about the human eye.

F5 is the strongest category of tornadoes; only about 2% of tornadoes are rated at this level.

If you visited a farm as a child or take your children there now, these are the most fun to see

There are many reasons why would should fight to conserve the environment and the animals that live in them besides protecting the delicate ecosystem that holds everything together. There are many popular animals that just might go instinct in the wild in a few years due to a variety of reasons many of them man made. Here is a list of the coolest animals that may cease to be found in the wild.

A list of Uranus moons by how long ago they were discovered.