WASHINGTON, DC - OCTOBER 19: In and effort to promote science, technology, engineering and mathematics (STEM) education, U.S. President Barack Obama greets guests during the second Astronomy Night on the South Lawn of the White House October 19, 2015 in Washington, DC. Obama hosted 300 scientists, engineers, astronauts, teachers and students for an evening of stargazing. (Photo by Chip Somodevilla/Getty Images)
