What this asteroid chart calculator does
This asteroid chart calculator gives you a quick way to explore two big ideas at once: impact energy and orbital behavior. You enter basic physical properties (size, density, speed, and angle), plus simple orbital parameters (semi-major axis and eccentricity), and the tool returns a compact report with visual bars.
The goal is not perfect prediction. The goal is understanding. You can test “what if?” scenarios and see how changing one input can dramatically change kinetic energy, crater size, and estimated severity.
How the calculator estimates asteroid effects
1) Mass estimate
The calculator assumes a spherical asteroid. Mass is estimated from volume and density: volume = 4/3 × π × r³, then mass = volume × density.
2) Impact energy
Kinetic energy is calculated with 1/2 × mass × velocity². A simple angle adjustment is used so steeper entry angles produce higher effective impact coupling than shallow entries.
3) TNT equivalent
Energy in joules is converted into megatons of TNT for easier interpretation. This helps you compare events across familiar scales.
4) Crater and damage radius
Crater size is estimated using a simplified scaling law that depends on asteroid diameter, velocity, and angle. A rough severe-damage radius is also included to give a “distance sense” for scenario planning and science communication.
What the orbit chart means
The second chart uses your semi-major axis and eccentricity to estimate orbital distance over 12 evenly spaced positions. It is a quick visualization of where the object is closer to the Sun (perihelion) and farther away (aphelion).
- Semi-major axis (AU): controls average orbital size and orbital period.
- Eccentricity: controls how stretched the orbit is.
- Period: estimated from Kepler’s third law, P ≈ √(a³) years.
How to use this tool well
Try sensitivity testing
Keep everything fixed and change one value at a time. For example, double diameter and watch how mass and energy jump. This is a great way to build intuition for non-linear systems.
Use realistic input ranges
Typical stony asteroid densities are often around 2,000–3,500 kg/m³. Impact velocities in Earth encounters can vary widely, but 12–30 km/s is a common educational range.
Remember model limits
Real impacts depend on composition, fragmentation, atmosphere, impact location, target geology, and water depth. Professional impact studies use far more detailed physics and uncertainty analysis.
Quick interpretation guide
- < 1 Mt: likely local-scale effects or airburst-dominated scenario.
- 1–50 Mt: serious local to city-scale hazard potential.
- 50–1000 Mt: regional-scale consequences possible.
- > 1000 Mt: very high-energy event with broad consequences.
Final note
If you want official close-approach data, orbit solutions, and impact probability monitoring, use trusted sources like NASA CNEOS, JPL Small-Body Database, and ESA’s NEO Coordination Centre. This calculator is best used as a learning and communication companion.