Top stories: transgender athletes, water on Mars, and a climate-cooling arachnid
This scientist is racing to discover how gender transitions alter athletic performance—including her own
In 2015, Joanna Harper, a medical physicist and runner, published the first study of transgender athletes’ race times, finding no advantage for transgender women who had been receiving hormone therapy, thanks to their previous exposure to male levels of testosterone. The groundbreaking study launched Harper into an advisory role for organizations such as the International Olympic Committee that are revising rules for transgender competitors. Harper—who herself transitioned more than a decade ago—is in the middle of the biggest study to date to examine athletic performance during gender transitions.
Liquid water spied deep below polar ice cap on Mars
The first liquid water has been found on the Red Planet, in a lake far beneath the ice cap at Mars’s south pole. Detected from orbit using ice-penetrating radar device known as the Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument, the lake is probably frigid and full of salts—an unlikely habitat for life. But the discovery is sure to intensify the hunt for other buried layers of water that might be more hospitable.
Could this tiny spider be helping the Arctic stay cool?
The 1.25-centimeter-long wolf spider may be having an outsize effect on the Arctic climate. When temperatures rise, the arachnids switch up their diets, eating each other instead of an insect that keeps a greenhouse gas–belching fungus in check, researchers report. As a result, the spiders may be indirectly reducing greenhouse gases over the Arctic and keeping the region cooler than it would be otherwise.
Here’s the sexual harassment report that felled a famed geneticist—and his defense
The 97-page report that triggered the 1 July termination of Francisco Ayala from the University of California (UC), Irvine, describes a long-standing pattern of behavior by the prominent evolutionary geneticist that continued even after he was warned to stop in 2015. The report details off-color remarks and repeated unsolicited compliments on women’s physical appearances—behaviors witnessed by one or more of the 61 people interviewed for the investigation—which UC Irvine stated are in violation of its sexual harassment policies.
Outer space may have just gotten a bit closer
A new study argues that the boundary between Earth’s atmosphere and outer space—known as the Kármán line—is 20 kilometers, or about 20%, closer than scientists thought. Though the new definition won’t make a difference for launching rockets and spacecraft, it could help clarify a legal debate that will set the rules for space policy—and commercial spaceflight—for years to come.