Some young visitors are seen at one of NASA's exhibits at the Earth Day event on Thursday, April 19, 2018 at Union Station in Washington, D.C. Photo Credit: (NASA/Aubrey Gemignani)
Some young visitors are seen at one of NASA's exhibits at the Earth Day event on Thursday, April 19, 2018 at Union Station in Washington, D.C. Photo Credit: (NASA/Aubrey Gemignani)