Simulating Planetary Interior Dynamics with Extreme Rheology.
SPIDER is an interior thermal-evolution module of the PROTEUS coupled atmosphere-interior framework. It is a 1-D parameterised interior dynamics code that solves the entropy evolution (Bower et al. 2018) of a rocky planet's mantle on a staggered finite-difference mesh, integrated in time with SUNDIALS through PETSc. It handles coexisting melt and solid across the whole mantle, volatile cycling, redox reactions, and a parameterised coupling to an outgassed atmosphere.
SPIDER runs standalone for magma-ocean studies, or as a subprocess of PROTEUS, where each coupling step it reads the surface boundary condition from the atmosphere module and returns the interior state through a JSON output contract.
git clone https://github.com/FormingWorlds/SPIDER.git
cd SPIDER
./tools/get_spider.sh # installs a pinned PETSc, then builds the spider binary
./spider -options_file tests/opts/blackbody50.opts # a first runSee the installation guide for the manual PETSc route, quadruple-precision builds, and cluster setup, and the first-run tutorial for a walkthrough with plots.
Full documentation is at proteus-framework.org/SPIDER, including:
- Getting started: the quickest path from a clone to a first model.
- How-to guides: install, test, build robust tests, supply an external mesh, couple to PROTEUS, and release.
- Reference: the runtime options generated from the source, and the publication list.
- Explanations: thermodynamics, mass and energy transport, material properties, boundary conditions, the hybrid equation of state, and the numerical schemes.
- Validation anchors: the per-source inventory of reference-pinned tests, each tied to a published benchmark, an analytical limit, or an independent cross-check.
SPIDER is the C, PETSc-based interior module of the PROTEUS framework for coupled atmosphere-interior evolution of rocky planets and exoplanets. Its sibling interior module, ARAGOG, solves the same entropy evolution in a Python and JAX implementation and serves as an independent cross-check; Zalmoxis can supply SPIDER with an external structural mesh for non-Earth-like compositions.
If you use SPIDER in published work, please cite the methods papers below; the metadata is in CITATION.cff and the full list is on the Publications page.
- Bower, D.J., Sanan, P., & Wolf, A.S. (2018). Numerical solution of a non-linear conservation law applicable to the interior dynamics of partially molten planets. Phys. Earth Planet. Inter. 274, 49-62. [DOI] [arXiv]
- Wolf, A.S., & Bower, D.J. (2018). An equation of state for high pressure-temperature liquids (RTpress) with application to MgSiO3 melt. Phys. Earth Planet. Inter. 278, 59-74. [DOI]
- Bower, D.J., Kitzmann, D., Wolf, A.S., Sanan, P., Dorn, C., & Oza, A.V. (2019). Linking the evolution of terrestrial interiors and an early outgassed atmosphere to astrophysical observations. Astron. Astrophys. 631, A103. [DOI] [arXiv]
- Bower, D.J., Hakim, K., Sossi, P.A., & Sanan, P. (2022). Retention of water in terrestrial magma oceans and carbon-rich early atmospheres. Planet. Sci. J. 3, 93. [DOI] [arXiv]
If your configuration uses the PALEOS equation-of-state tables (for example an external structural mesh from Zalmoxis built on them), please also cite:
- Attia, M., Lichtenberg, T., Jungová, E., & Sastre, M. (2026). PALEOS: Multiphase Equations of State and Mass-Radius Relations for Exoplanet Interiors. [ADS] [arXiv]
GNU General Public License v3.0. SPIDER is part of the PROTEUS framework.