(Left to right): Science Picture Co/Science Source; ESO/S. Guisard; Ian Cartwright/Institute of Archaeology, University of Oxford

Top stories: A newly found black hole, water-cooling solar panels, and a bone-strengthening therapy

PETA versus the postdoc: Animal rights group targets young researcher for first time

Animal rights group People for the Ethical Treatment of Animals appears to be targeting young scientists for the first time. For decades, the group has focused its efforts on established researchers (i.e. those with tenure). But it has recently launched an aggressive campaign against a postdoc at Yale University, who is still very early in her scientific career. Critics worry that the organization is trying to send a message to all young scientists: Don't even think about getting into animal research.

New water-cooling solar panels could lower the cost of air conditioning by 20%

Most of us have heard of solar water heaters. Now, there’s a solar water cooler, and the technology may sharply lower the cost of industrial-scale air conditioning and refrigeration. After placing three water-cooling panels atop a building and circulating water through them, researchers report this week that their setup cooled the water as much as 5°C below the ambient temperature over 3 days of testing. If integrated into a typical air conditioning unit for a two-story building in Las Vegas, Nevada, the solar water cooler would lower the building’s air conditioning electrical demand by 21% over a summer.

Neandertals and early modern humans probably didn’t meet at rumored rendezvous site

Croatia’s scenic Vindija Cave was thought to be a potential trysting site for Neandertals and early modern humans some 32,000 years ago. Now, a new study questions that idea, using a more exacting form of radiocarbon dating to suggest instead that Neandertals used the cave 40,000 years ago—some 8000 years before modern humans lived in that part of Europe. If true, the find casts doubt on the long-held assumption by some that the two hominids overlapped in the region.

Long-rumored midsized black hole may be hiding out in the Milky Way

Astronomers have found the best evidence yet for the existence of a midsized black hole—long-rumored objects bigger than the small black holes formed from a single star, yet far smaller than the giant ones lurking at the centers of galaxies—and it’s hiding out in our own Milky Way. If the discovery is confirmed, it could indicate that our galaxy has grown by cannibalizing its smaller neighbors.

New therapy could protect diabetic bones

A drug that can reverse diabetes and obesity in mice may have an unexpected benefit: strengthening bones. Experiments with a compound called TNP (2,4,6-trinitrophenol, also known as picric acid), which researchers often use to study obesity and diabetes, show that in mice the therapy can promote the formation of new bone. That’s in contrast to many diabetes drugs now in wide use that leave patients’ bones weaker. If TNP has similar effects in humans, it may even be able to stimulate bone growth after fractures or prevent bone loss due to aging or disuse.

Trump picks NASA chief, NOAA second-in-command

President Donald Trump has announced his picks for two prominent science-related positions in his administration. He intends to nominate Representative Jim Bridenstine (R–OK) to be the administrator of NASA, the White House announced this week. And he wants Rear Admiral Timothy Gallaudet, a former oceanographer of the Navy, to be assistant secretary of commerce for oceans and atmosphere, the No. 2 job at the National Oceanic and Atmospheric Administration. Both nominees will have to be confirmed by the U.S. Senate.