One of the first maps of Mars, published by an Italian astronomer in 1877, with its pattern of canals, fueled belief in intelligent life forms on the distant red planet – a hope that continued into the 1960s. Although the Martian canals have long sin...

Gems are objects of wealth, icons of beauty, and emblems of the very best of everything. They are kept as signs of prestige or power. Given as tokens of love and affection, they also come in a kaleidoscopic array of hues and can be either mineral or...

The Great Plains were once among the greatest grasslands on the planet. But as the United States and Canada grew westward, the Plains were plowed up, fenced in, overgrazed, and otherwise degraded. Today, this fragmented landscape is the most endanger...