139 asteroids are passing through
Earth's neighborhood this month.Data · JPL Horizons MAY · 2026
139 asteroids are passing through
Earth's neighborhood this month.NEO Radar is a real orbital-mechanics engine for tracking Near-Earth Objects. 47 high-fidelity objects with full RK4 N-body dynamics, plus 41,812 MPC catalog asteroids with real positions — all 8 planets simulated. Click any asteroid for a complete physical dossier.
Next Close Approach
0.71lunar distances
2025 PT5 · in 2 d 14 h 22 m
2024 YR4
a=1.18 AU · e=0.66
Monitor 0.94 LD
Apophis
99942 · NEA, Aten
Caution 31,800 km
2025 QV1
a=0.93 AU · e=0.41
Safe 2.4 LD
Engineering
Real physics. Not approximations.
Every trajectory in NEO Radar is integrated from JPL Horizons ephemeris with full gravitational perturbation from the outer planets. The numbers you see are the numbers a mission planner would see.
E₀ → E₁ → E₂ → E₃ ε < 1e-12
01 / Kepler
Solves Kepler's equation, not lookup tables.
Mean anomaly to eccentric anomaly via Newton-Raphson with adaptive seed, converging to 1×10⁻¹² in under four iterations even for high-eccentricity orbits.
M → E → ν e < 0.99 ε = 1e-12
\+ Δv
02 / Perturbation
Jupiter and Saturn pulled, and you see the pull.
Toggle outer-planet gravity on or off. The uncertainty cone widens visibly on Jupiter-flyby trajectories — what mission planners call the keyhole problem.
N-body RK4 Adaptive Δt All 8 planets
1999 2025 2050 26 yr arc σ = 412 km
03 / Data
JPL Horizons ephemeris, locally cached.
Pulled directly from JPL Horizons and pinned to disk for instant access. Observation arcs and uncertainty parameters travel with every object — no approximations, no drift.
NASA NeoWs SPICE kernels Local cache
Trust
How accurate is it?
We benchmark every NEO Radar trajectory against JPL Horizons ephemeris over a 50-year window. Where simplified two-body models drift by tens of thousands of kilometers, NEO Radar stays inside the actual uncertainty cone.
Position accuracy is computed as RMS deviation from JPL ground truth across the same 50-year window for the 47 high-fidelity objects.
NEO Radar 412 km
Kepler-only 18,400 km
2-body sim 112,000 km
Position RMS · 50 yr
412 km
Catalog Objects
41,859
Integrator Order
RK4
Adaptive Δt
10⁻³–10⁰ d