Introduced by Michel Hénon in 1976, this simple 2D discrete map produces a remarkable strange attractor. The iteration is:
At the classic parameters (a=1.4, b=0.3) the attractor has a fractal structure with Hausdorff dimension ≈ 1.261. Each "leaf" of the attractor is actually a Cantor set — infinitely many thin sheets. The map contracts area (Jacobian |b| < 1) while folding it, creating the hallmark stretch-and-fold of chaos. The Lyapunov exponent λ₁ ≈ 0.419 > 0 confirms sensitive dependence on initial conditions.