Meteor Wake - 2D Atmospheric Entry, Ablation and Light Curve

Single-body entry equations

For a meteoroid of mass m and cross-section A in an exponential atmosphere ρ(h) = ρ₀ e^-h/H (H = 7.16 km), along a straight path at angle γ: dv/dt = -Cd ρ A v² / (2m) (plus gravity), dm/dt = -Λ ρ A v³ / (2Q), dh/dt = -v sin γ. Light output is taken as 1 % of the kinetic power carried by the ablated mass, ½ v² |dm/dt|.

Closed forms used for the checks

Without ablation, v = v_∞ exp(-β e^-h/H) with β = C_d ρ₀ H A / (2 m sin γ), and the deceleration peaks at v_∞ / √e with value v_∞² sin γ / (2 e H) at h = H ln(2β). With ablation, dividing the two rate equations gives m = m₀ exp(-σ(v_∞² - v²)/2) with σ = Λ / (C_d Q).

Honest simplifications: one non-rotating, non-fragmenting body, a flat exponential atmosphere, constant C_d, Λ and 1 % luminous efficiency, no Earth curvature, no shock-heated wake chemistry. Real meteoroids often fragment, so real light curves are more jagged.

• Sand grain: it burns up high; compare with Large stony, 2 m, which reaches the lower atmosphere.
• Steep and slow vs a shallow angle: where does the deceleration peak move?
• Raise the density: the meteoroid penetrates deeper before it flares.
• Use the slow-motion slider to watch the wake develop.