5 Most Incredible Discoveries of the Week

A strange crater in an irrigation pond and a Neanderthal cave carving make the list:

• Mystery Crater Surfaces on Utah Farm: Gary Dalton was draining the irrigation pond on his farmland in Circleville, Utah, when he made a startling discovery: a giant crater staring back up at him from the bottom of the basin. The algae-filled hole, measuring about 25 feet across and at least 7 inches deep in the center, has baffled not only the Daltons but area geologists as well, though they've got a leading, non-alien theory.
• Carving May Prove Neanderthals Were Artists: An ancient etching inside a cave in Gibraltar may mean that Neanderthals' knuckles weren't dragging quite as much as we believed. The 39,000-year-old design suggests Neanderthals were capable of symbolic thinking, a trait once believed to be unique to modern humans, an anthropologist argues in a new study. It kind of looks like a hashtag.

• Patchy Grass Offers a Big Stonehenge Clue: A layperson's simple observation may help solve a Stonehenge mystery. A historic preservation worker noticed that the grass didn't grow so well in certain areas near the ancient monument—meaning it's possible that giant stones were once placed there and suggesting that the outer ring of the site may once have been a full circle.
• Why You Should Nap After Coffee: Debating between a cup of joe or a short nap to make it through the day? Perhaps you should try both. Scientists say a "coffee nap"—having a cup of coffee and then a 20-minute nap—will allow for maximum alertness when you wake. It might seem like coffee and naps wouldn't mesh well together, but there's a reasonable explanation why it works.
• We Understand Probability as Toddlers: Don't understand probability? Try asking a 2-year-old. A study suggests they have an instinctive understanding of the ideas involved, and that a little observation goes a long way.

Click to read about more discoveries, including a theory about what's causing Antarctic sea levels to rise so fast. (More discoveries stories.)