Today, Mars will be closer to our earth than it has been in over 100,000 years. We know a great deal about the red planet from centuries of work by astronomers and from decades of data beamed back from unmanned spacecraft like the twin Viking landers, which in 1976 became the first spacecraft to land successfully on the planet. "To a certain extent, we think we know quite a bit about Mars now based upon Viking," said Arden Albee, a mission scientist with the Mars Global Surveyor, a satellite in orbit around the red planet. "But probably a lot of the things we think we know are wrong." Here's some of what know — or think we know — about Mars. Full story.

As the weather heats up, so does the chance for injury from leaking batteries. Batteries that are left in unused electrical devices, especially on hot days, may break down and leak caustic chemicals. Hand injuries can result from contact with the chemicals. It is recommended that batteries be removed from devices that will be unused for extended periods of time, and stored in a cool, dry place (55 to 77 degrees is ideal). If employees do come in contact with these chemicals, they should quickly rinse their hands with cool tap water. If redness, irritation or burning occurs, seek medical advice as soon as possible.