Ancient Trees Show When The Earth's Magnetic Field Last Flipped Out A precise record of the last major reversal of the Earth's magnetic poles can be found in ancient trees. Researchers say this event 42,000 years ago had a huge impact on the planet and ancient humans. Nell Greenfieldboyce
Dinosaur-Killing Impact Came From Edge Of Solar System, New Theory Suggests Harvard researchers say a comet from deep space — not an asteroid from the belt past Mars — was responsible for the mass extinction. Others are skeptical. Matthew S. Schwartz
A Look At The New U.S. Coronavirus Variants In recent months, we've learned about several new variants of the coronavirus that have popped up in the U.S. Scientists recently reported seven new and distinct variants. Ailsa Chang
Pillagers Of Tropical Forests Can't Hide Behind Clouds Anymore Environmental watchdogs now can detect deforestation even when it's hidden from sight by rain and clouds. They're using data from radar on a European satellite. Dan Charles
'Perseverance' Mission Will Put NASA Wheels Back On Mars Another six-wheeled rover is about to land on Mars. NASA Perseverance's mission is headed to Jezero Crater, which once may have been a lake. It's carrying two new items: a microphone and a helicopter. Joe Palca
What A Brain Organoid Grown With Neanderthal DNA Tells Us About Modern Humans A brain organoid grown with Neanderthal DNA reveals how evolution shaped the brains of modern humans and adds to evidence that brain differences helped us survive while our human cousins went extinct. Jon Hamilton
8-Year-Old Calls Out NPR For Lack Of Dinosaur Stories How can All Things Considered consider all things without considering dinosaurs? That's the question posed by 8-year-old Leo Shidla of Minneapolis. Mary Louise Kelly
Hope Heads For A Rendezvous With Mars The UAE probe arrives at Mars on Tuesday, Feb 9. Its purpose is to both study the weather on Mars as well as inspire the next generation of that country's scientists and engineers. Joe Palca
Nagin Cox: What Does Time On Mars Teach Us About Time On Earth? NASA engineer Nagin Cox lives on Earth but works on Mars time, where days are longer and time works differently. Her work with the rovers has entirely changed the way she thinks about time on Earth. NPR/TED Staff
Lucy Cooke: How Did Slowness Become The Sloth's Secret To Survival? It's easy to see why sloths have become icons of laziness. But zoologist Lucy Cooke says behind their leisurely pace is a marvelous evolutionary advantage that is the secret to their survival. NPR/TED Staff
