This Week in Science: Painting Mercury Black, Tampon Tech, and Why Beards Are Back

Seven days, lots of science in the news. Here’s our roundup of some of the week’s most notable and quotable items:

Scientists in the U.K. are using tampons to measure local water quality.

While the West is still working out some issues with medical consent, historians in Turkey have found a medical consent form dating back to the 16th century.

There’s a prenatal test more accurate than standard methods at detecting Down syndrome.

Primate social research has led scientists to think that elaborate beards and mustaches may be a way for human men to compete with each other.

The blackpoll warbler, a tiny bird that weighs just as much as three teaspoons of sugar, is able to fly 2,700 miles across the Atlantic Ocean over three days without food or rest.

Mercury’s dark surface may have been painted with black dust from comets.

Poverty harms a child’s brain development.

Polar bears are starting to hunt on land more often as sea ice shrinks, but it is doubtful that the new diet has enough fat to allow them to thrive.

The factory workers of the future may be 3D-printed robotic ants.

It may have been spry enough to complete a Martian marathon, but the Opportunity rover’s memory problems are getting worse.

Two engineering students built a fire extinguisher that uses low-frequency sound waves to extinguish flames.

Male mice might woo their mates with squeaky songs, and rats, new research suggests, are apparently pretty gender fluid.

Researchers redated the remains of “Little Foot,” an ancient member of the human family tree, to about 3.7 million years ago—a bit older than the famous find “Lucy”—but still aren’t exactly sure what species he belongs to: Australopithecus africanus, a newly described species Australopithecus prometheus, or some other species.

A lunar eclipse set for this weekend will be the shortest one this century, with the moment of total eclipse lasting for just five minutes.

Image: Sarah Peavey