(Left to right): Josh Valenzuela/UNM; German Archaeological Institute (DAI); Tomohiro Tachi/Flickr

Top stories: Mysterious human skull carvings, algorithms for origami, and NASA’s newest astronauts

Carved human skulls found in ancient stone temple

Archaeologists have made a remarkable find in a 12,000-year-old stone temple in southeastern Turkey. Among tens of thousands of animal bones and a statue that may depict a kneeling figure holding a human head, researchers have uncovered the remains of human skulls that were stripped of their flesh and carved with deep, straight grooves running front to back. The carvings represent the first evidence of skull decoration in the archaeological record of the region. And although the purpose of the carvings is unclear, they may have been part of an ancient religious practice.

These orbiting black holes may be locked in one of the universe’s tightest embraces

In the heart of a huge, warped galaxy about 750 million light-years from Earth, a dance is unfolding. And the dancers—two of the largest black holes on record—may be orbiting each other in the closest such pas de deux ever reported, according to a new study. The black holes are separated by just 24 light-years, and together contain 15 billion times the mass of our sun. This week, astronomers reported evidence that the black holes appear to be circling each other on a 30,000-year cycle.

Origami algorithm will help you fold paper like a master

If you’ve ever tried to fold an origami butterfly and watched helplessly as your hands mangled it into a sickly pterodactyl, you know folding paper can be tricky. A new algorithm could help. Once you’ve created a polyhedral design on your computer, say a bunny, the “Origamizer” maps its flat faces—triangles and such—onto a piece of paper. It then figures out how to fold all of the excess paper out of the way so the faces come together in just the right way.

Cancer studies pass reproducibility test

A high-profile project aiming to test reproducibility in cancer biology has released a second batch of results, and this time the news is good: Most of the experiments from two key cancer papers could be repeated. The unusual initiative was inspired by reports from two drugs companies that up to 89% of preclinical biomedical studies didn’t hold up in their labs. The latest replication studies, published this week in eLife, come on top of five published in January that delivered a mixed message about whether high-impact cancer research can be reproduced.

Weighing the universe's most elusive particle

It might seem absurd that physicists don't know how much neutrinos weigh, given that the universe contains more of them than any other type of matter particle. However, it's impossible to capture neutrinos, so for 70 years, physicists have tried to infer the neutrino's mass by studying a particular nuclear decay from which the particle emerges. Now, scientists are pushing that classic experiment to its ultimate limits.

NASA’s new astronaut corps features an abundance of scientific talent

As a doctoral student at the University of California, Los Angeles, Jessica Watkins wrote her dissertation on the extended landslides that occur on Mars, relying on images from orbiting satellites and NASA’s rovers. Now, as one of NASA’s 12 newest astronauts, Watkins just might someday get the chance to visit those martian terrains. Although a majority of those deemed to “have the right stuff” are active military personnel with extensive flight experience, four of the new astronauts are civilians who hold science and engineering Ph.D.s. Here are three of their stories.