Thousands of pro-science and environmental activists rallied on the National Mall before marching toward the Capitol on Saturday, the 47th observation of Earth Day. The march in Washington was accompanied by other science marches across the U.S. and world. It was organized to show support for the scientific community at a time when its members, and supporters, say they feel threatened by the policies and potential policies of President Donald Trump.

Here’s a look at the Washington event in photos: