The March for Science may have been a grassroots phenomenon, but the event is quickly becoming a highly organized affair—one with the support of some major sponsors from the association world.

On Thursday, the March for Science announced 27 associations and nonprofit organizations that will partner with the event, further expanding its reach. The March for Science will team with the Earth Day Network (EDN) to co-organize the main April 22 event, tying its efforts with the existing Earth Day March. Meanwhile, the American Association for the Advancement of Science (AAAS), Sigma Xi, the Entomological Society of America (ESA), NextGen Climate America, and ScienceDebate.org signed on to the event as major partners.

Groups taking part in the event emphasize that they did their homework. As Stat notes, the move by AAAS to support a rally of this nature is unusual, as the group is considered nonpartisan, but the event came to life in response to President Donald Trump. In comments to the website, AAAS CEO Rush Holt cited the agreement with march organizers that the event would have a nonpartisan focus.

“It’s quite explicitly pro-science rather than against any partisan position,” Holt stated. “Now, it’s clear that the march is intended to play up the importance of the conditions that are necessary for science to thrive and to advocate for the defense of those conditions.”

ESA, likewise, emphasized in a statement that the march’s goals align with the association’s strategic principles.

“We have an obligation to promote the responsible conduct of science and speak out against any proposed interference with the free exchange of scientific knowledge,” ESA President Susan J. Weller, Ph.D. said. “I encourage ESA members to support this celebration of science.”

And the American Geophysical Union, which has also signed on as a partner, noted that it only decided to support the march after consulting with event organizers and researching the goals of the endeavor, which came to life after the idea went viral on Twitter and Reddit.

While the seed of the idea came to life in a modest way, the resulting event is proving far-reaching, with nearly 300 satellite events already confirmed. Organizers also expect to add additional partners in the coming weeks.

“This started as an idea, but it’s rapidly actualizing into a global movement,” said Valorie Aquino, one of the march’s three national co-chairs, in a press release. “Scientific integrity serves everyone, and we need to speak out for science together. We’re thrilled and inspired that our message is resonating with so many organizations and so many people who have been advancing and defending science for years.”

A scene from the recent Stand Up for Science rally, held in Boston near this year's AAAS annual meeting. (Adam Salsman/Flickr)