Kinetic Impactor Momentum Enhancement (β)

Impactor Setup

Impactor mass 570 kg

Closing velocity 6.6 km/s

Momentum enhancement β 3.6

Warning time before encounter 2.0 yr

Deflection Result

Awaiting impact…

Δv delivered

0 mm/s

Momentum p = mv

0 kg·m/s

B-plane shift @ encounter

0 km

Target mass M

5.2×10⁹ kg

How it works

A kinetic impactor doesn't push the asteroid directly — it transfers momentum on impact, then the asteroid's own ejecta plume acts like a rocket exhaust and adds extra thrust. NASA's DART mission (2022) measured this "momentum enhancement factor" β ≈ 3.6 for Dimorphos:

Δv = β · (m · v) / M
  m = impactor mass, v = closing velocity
  M = target asteroid mass, β ≥ 1 (β=1: no ejecta, pure inelastic hit)

Because Δv is tiny (millimetres per second) compared to orbital speeds, planetary defenders use a linear approximation: the along-track position shift keeps growing for as long as the asteroid coasts before its next close approach to Earth —

Shift at encounter ≈ Δv × T_lead

This is why lead time matters more than raw power: doubling the warning time doubles the eventual miss distance for the same nudge, which is why early detection (the goal of surveys like NASA's NEO Surveyor) is as critical to planetary defense as the impactor itself.

Impactor mass / velocity — sets the raw momentum m·v delivered on impact (DART's defaults: 570 kg at 6.6 km/s relative to Dimorphos).
β — how much the ejecta plume amplifies that momentum; β=1 means no enhancement, β≈3.6 matches the real DART result.
Warning time — how long the deflected asteroid coasts before it would have crossed Earth's path; longer lead time turns a millimetre-per-second nudge into thousands of kilometres of miss distance.

Target asteroid Impactor Original path Deflected path

⚠ Couldn't load the 3D engineThree.js failed to load from the CDN. Check your connection and reload.