Space scientists angry over a White House proposal to cut NASA’s planetary science budget by 20 percent next year are being urged to present a unified front to policymakers in Washington.

“Part of the reason that planetary [science] got ‘whacked’ … is because the planetary community is perceived in certain powerful circles as being weak,” veteran science journalist and space historian Andrew Chaikin said March 20 during a town hall gathering of disgruntled space scientists at the 43rd Lunar and Planetary Science Conference in Woodland, Texas. “We have to come together and show them you’re not weak.”

Chaikin’s view was backed by Steven Squyres, the Cornell University professor who chairs the NASA Advisory Council and serves as principal investigator for NASA’s Opportunity rover currently exploring Mars. Last year, Squyres chaired a major space science review, known as the decadal survey, that set goals for NASA’s planetary science program through 2022.

A year later, the findings of that detailed space exploration blueprint have fallen victim to budget cuts.

“There’s a need to respond as a united community … that cannot be stressed too much,” Squyres said. He urged the gathering to not react as a community of Mars fans, or Europa fans, or even as a community of planetary scientists. “Respond as a community of space scientists,” he said.

Squyres said he has spent a lot of time since NASA’s 2013 budget proposal was released in February talking to U.S. lawmakers and other decision-makers in Washington.

“I will tell you that as bad as this looks … [there are those] looking for ways to cut even further,” Squyres said. “What we must not do is to give anybody a reason for cutting planetary further. … There’s going to be pressure to do that.”

Squyres added: “There’s no surer way to give budget cutters, and there are a lot of them out there, a reason to go after the planetary program than to project [the] appearance of disunity, disarray, disagreement, as to what we should be doing. We must speak as one voice.”

Laurie Leshin, a former NASA deputy associate administrator for exploration systems and now a dean at Rensselaer Polytechnic Institute and president of the American Geophysical Union’s planetary sciences section, also urged scientists in attendance to let lawmakers on Capitol Hill know they are not happy about the proposed reductions.

“This is an egregious cut,” Leshin said. “NASA can’t fight this fight for us. We have to take it to the Hill.”

NASA announced in February that it was pulling out of the European ExoMars program, which still aims to launch spacecraft in 2016 and 2018 with Russia to set the stage for an eventual Mars sample-return mission. The cuts outlined in NASA’s 2013 budget also mean the United States will not be embarking on flagship-class missions to the outer planets any time soon.

Leshin urged space scientists to get engaged for the fight. She suggested that a weak planetary science program is going to result in a weak NASA at a time when the agency is attempting to chart a course for human space missions beyond low Earth orbit.

“We need to get this reversed. If this cut stands this year, restoration in future budgets will be much more difficult. Our time is now, these next few months,” Leshin said.