During the H1N1 swine flu pandemic, President Barack Obama was vaccinated by a White House nurse. It took a little more than five months from the discovery of the virus to develop a vaccine. Pete Souza/AP hide caption

NASA mathematician Katherine Johnson, pictured at the 2017 Academy Awards, was one of the women profiled in the book and film Hidden Figures. She died Monday at 101. Jordan Strauss/Invision/AP hide caption

A crowd gathers at the South Bristol's annual ice harvest. Rebecca Conley/Maine Public hide caption

Craigslist founder Craig Newmark (L) and CEO Jim Buckmaster pose in front of the Craigslist office March 21, 2006 in San Francisco. The site has become a behemoth but changed little aesthetically. Justin Sullivan/Getty Images hide caption

Efforts to carve out new states are not a unique concept. A man on stilts wears State of Jefferson regalia at a Timber Unity rally in front of the Oregon Capitol in Salem, Ore., this month. The push for a State of Jefferson began in 1941. Bradley Parks/OPB hide caption

Specialist Mark Fitzgerald works on the floor of the New York Stock Exchange, Monday, Feb. 24, 2020. Markets are down across Europe, Asia, and the U.S. as the virus spreads to more countries around the world. Richard Drew/AP hide caption

Sir John Eliot Gardiner and the Orchestre Révolutionnaire et Romantique are performing all nine of Beethoven's symphonies in a series of concerts celebrating the composer's 250th birthday. Chris Lee/Courtesy of the artist hide caption