Planet Four
Studying Mars with the help of Citizen Science
The Red Planet is a unique and dynamic world. Through the power of the Internet and its volunteers, we explore the surface, climate, and history of Mars with the Planet Four projects.
It is difficult if not impossible for computer algorithms to accurately map individual polar seasonal fans, spot araneiform (‘spider’) erosion, and identify polygonal ridges. These features visible from orbit are easily spotted by the human eye, and volunteers from around the world have contributed by mapping seasonal fans, polygonal ridges, and araneiforms in Mars Reconnaissance Orbiter imagery.
p4tools
The p4tools Python library provides easy access to the Planet Four citizen science catalogs. Install via pip install p4tools and get started with a few lines:
- Download and cache fan and blotch catalogs automatically via pooch
- Built-in plotting tools for catalog visualization
- CLI interface via the
p4command
Current research
Our latest analysis covers 463 HiRISE observations spanning Mars Years 28–33, studying inter- and intra-annual variability of dark regolith deposits at Mars’ south pole (EGU 2026). The dataset reveals a mean jet deposit ground coverage of 6.89% with high inter-annual repeatability, providing new constraints on seasonal CO2 jet activity.