Can Coronavirus Reactivate In Patients After Recovery? These days, newsfeeds are overloaded with stories of the coronavirus, but Science Friday continues to explain the science behind COVID-19 headlines. Here, we learn about South Korea reports of 116 patients who recovered from the disease tested positive. Angela Rasmussen, associate research scientist and virologist at the Columbia Mailman School of Public Health, breaks down how reactivation works in viruses in diseases such as herpes. Plus, Rasmussen talks about human challenge trials—where participants are given a vaccine and inoculated with a virus—and the debate over the usage of these trials to develop a COVID-19 vaccine. Earth Day Goes Digital Next Wednesday is the 50th anniversary of Earth Day, marking five decades of environmental actions, like community cleanup, planting trees, or marching in the streets.  But this year, coronavirus has led to the cancellation of planned marches and large-scale events. Instead, many people will be participating in a digital Earth Day. Ira talks to Kathleen Rogers, president of the Earth Day Network about what people can do to participate, parallels between climate change and coronavirus, and environmental action in the age of the Trump administration.  Uncovering Antarctica's Rainforest Scientists found 90 million-year-old evidence that Antarctica wasn’t always a snow-covered continent. New ice core research provides evidence that the frozen land was once a temperature rainforest. Marine geologist Johann Klages, an author on the study, discusses what temperature the Earth would need to be to support such an environment in Antarctica, and how that can be used to create more accurate climate models.  Show Off Your Backyard Birds And Bugs Get involved in Citizen Science Month by snapping pictures of nature from your backyard with City Nature Challenge.