A visitor gives a high five after learning about oceans 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)
A visitor gives a high five after learning about oceans 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)