A proposed 47% cut to NASA science from the Trump administration has sounded the alarm among scientists and space advocates — and Bill Nye is leading the charge to stop it.

Driving the news: Nye — known as “the Science Guy” — will join more than 300 advocates from a coalition of nearly 20 science and education groups in Washington for a Day of Action on Monday, urging Congress to save NASA science.

Zoom out: The gathering in DC stems from the Trump administration’s plan to gut funding, while a government shutdown has already furloughed 85% of NASA staff.

The White House has even floated mass firings during the shutdown, putting long-term missions and jobs at risk.

Meanwhile, China is accelerating: planning a Mars Sample Return by 2028, a major Jupiter mission, a Venus atmosphere probe, and an asteroid defense swarm.

Flashback: Nye isn’t new to stepping in a political battle; he took over as CEO