Have you ever had to learn something new and repeat it over and over—until it feels like you’re doing it in your sleep? Maybe you are. In research published this week in the journal Cell Reports, scientists monitored the brain activity of two people implanted with fine grids of neural electrodes as part of a brain-computer interface study for tetraplegia: paralysis of all four limbs. With the implants and a computer model to process the signals, the study participants were able to use their thoughts to control the movement of a cursor on a computer screen. In the study, the participants were asked to play a memory-pattern game similar to the old “Simon” handheld electronic game, pressing a sequence of four buttons in a given order. Then, they were asked to rest and relax—even to nap if they wanted—while the researchers continued to observe their brain activity. They found that the participants’ brains replayed sequences of the game’s patterns during shallow, stage one non-REM sleep. The researchers think that this replaying may be connected to mechanisms the brain uses for memory consolidation and learning. Beata Jarosiewicz, one of the authors of the study, joins guest host John Dankosky to discuss their findings. While research continues on vaccines, antivirals, and other medical solutions to the coronavirus outbreak, there are already non-pharmaceutical interventions that public health experts know work. One of them is contact tracing, the process of identifying the people who have been exposed to a known person with COVID-19, and then helping those people avoid infecting others. But while using public health workers for contact tracing has helped contain diseases like Ebola and HIV, contact tracing effort for the much more contagious novel coronavirus could rely in part on digital tools. Around the globe, countries from Iceland, to Singapore have developed smartphone apps. Now, in the U.S., states are also looking to invest in contact tracing—both by hiring thousands of workers to help, but also developing their own apps. And last month, Apple and Google announced they were teaming up to develop a platform for all smartphones to opt in to a system that would tell them if they’d been exposed. But can an app do everything a person can? And will people trust an app with their health information? Producer Christie Taylor talks to two public health experts, Johns Hopkins University’s Crystal Watson, and Massachusetts General Hospital’s Louise Ivers, about the intensive and nuanced work of contact tracing and how digital solutions can fit in the picture. For centuries, we’ve been trying to get a better understanding of the surface of the moon. Different cultures have imagined faces, rabbits, and even toads hiding in the rocky features. Astronauts have walked on the lunar terrain—bringing back photographs and rock samples. And so far, there have been 21 moon landings. The most recent happened last January, when China successfully put a lander on the far side of the moon. Recently, USGS scientists used their expertise in map-making to pull together some of these scientific observations to catalogue the geology of the moon. They stitched together six Apollo-era moon maps, combined with modern satellite data, to create a 360-degree map of the geological structures on the moon. This “Unified Geologic Map of the Moon” was published last month. USGS research geologist James Skinner, one of the creators of the map, takes us through the terrain of the lunar surface, and talks about what it can tell us about the evolution of the moon. Plus. Michelle Nichols of the Adler Planetarium gives moon gazing tips to help you spot the different geological features of the moon.