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NEO Planetary Radar

JPL Sentry

Near-Earth asteroid close-approach tracking, orbit intersection physics, and kinetic impact modeling.

Impact Physics Formulas
1. Kinetic Impact Energy:
$E_k = \frac{1}{2} \cdot \left(\frac{4}{3}\pi \rho r^3\right) \cdot v^2$

Calculated in Megatons of TNT ($1\text{ Mt} = 4.184 \times 10^{15}\text{ Joules}$).

2. Crater Diameter Scaling:

Transient crater size follows Pi-scaling laws: $D_{crater} \approx 1.161 \cdot (\rho_i / \rho_t)^{1/3} \cdot L^{0.78} \cdot v^{0.44}$.

Tracked Asteroid Target

Diameter ($D$) 370 meters
Impact Velocity ($v$) 30.7 km/s
Density ($\rho$) 2,600 kg/m³

Impact Damage Matrix TORINO: 4

Kinetic Energy: 1,200 Megatons
Crater Diameter: 5.1 km
Crater Depth: 510 meters
Earthquake Mag: 6.8 Richter
Fireball Radius: 18.4 km
HELIOCENTRIC ORBITAL RADAR • 99942 APOPHIS
Hazard Class: PHA (Potentially Hazardous) MOID: 0.00031 AU (31,900 km)
Size Benchmark
Target Asteroid: 370 m
Eiffel Tower: 330 m
Empire State Bldg: 443 m
Burj Khalifa: 828 m
● Earth Orbit (1.0 AU)  •  ● Asteroid Trajectory  •  ● Sun (0.0 AU)