Science The fate of the most powerful X-ray telescope is in doubt NASA's budget proposal would basically axe the most powerful X-ray telescope in the world, and astronomers are scrambling to save it. Nell Greenfieldboyce
Science Dark energy — which causes the expansion of the universe — may be changing One of the big mysteries of the universe is how it's expanding. The phenomenon causing that expansion is known as dark energy — and recently, scientists have started to wonder if its changing. Regina Barber
Science Peekaboo! A baby tree kangaroo debuts at the Bronx Zoo The second baby of a tree-dwelling kangaroo made its public debut this week in New York, poking its pink head head out of its mom's furry white pouch. The Associated Press
Science Wild horses in the west: A look at America's mustang problem Scientists say there are more horses than the land can support. But some believe the horses should be left to run free.
Science A study finds that dogs can smell your stress — and make decisions accordingly Researchers made volunteers do public speaking and math on the spot, then showed them a calming video. Then, using sweat samples, glass jars and food bowls, they examined the emotional impact on dogs. Rachel Treisman
Science Here's a question for you: Do animals lie? A researcher shares examples of deception in the animal kingdom. Barry Gordemer
Science Astronomers are scrambling to save the world's most powerful X-ray space telescope NASA is facing a tight budget and wants to wrap up the Chandra X-ray Observatory, but astronomers don't want to see the 25-year-old X-ray space telescope mission go. Nell Greenfieldboyce
Science When did humans get to South America? This giant shelled mammal fossil may hold clues A fossil of an armadillo-like mammal appears to bear cut marks from butchering by humans, suggesting people were living in South America at least 20,000 years ago, even earlier than once thought. Ari Daniel
Environment A scientist in Belize hopes bats can galvanize locals to protect their forests A Belizean bat scientist is looking to these fuzzy, flying mammals to act as emissaries to galvanize the people of Belize to protect their forests. Ari Daniel
Science Animals at the Phoenix Zoo enjoy ice in the extreme heat Extreme heat isn't just hard on humans, which is why the Phoenix zoo delivers ice to grateful animals to keep them healthy and happy. Christina Estes
