fn main() {
    let pwyll = europas::geology::craters::pwyll();
    let cilix = europas::geology::craters::cilix();
    println!(
        "Pwyll: {} km, depth/diameter = {:.4}",
        pwyll.diameter_km,
        pwyll.depth_to_diameter_ratio()
    );
    println!(
        "Cilix: {} km, class = {}",
        cilix.diameter_km,
        europas::geology::craters::crater_class(cilix.diameter_km)
    );
    let impactor = europas::physics::collisions::ice_impactor();
    println!("Ice impactor KE: {:.2e} J", impactor.kinetic_energy_j());
}
