Intercepting Bennu

101955 Bennu is a 500 meter diameter Near Earth Asteroid, likely to crash into the Earth sometime in the next 20,000 years, and possibly sooner than 200 years from now. The impact energy would be equivalent to a 100 megaton bomb, or 4 times the explosive energy of the Mount Saint Helens eruption. That won't be a global catastrophe, but it could kill millions of people if it impacted in the wrong place.

Bennu is an Apollo asteroid, with a semimajor axis of

Earth	Bennu
	7.00E+10	kg Mass
1	1.1264	AU Semimajor axis
149597900	168507075	km Semimajor axis
1	1.1954	year Period
365.2422	436.64	day Period
0.0167086	0.20375	Eccentricity
29.790	28.666	km/s v0
1.0167	1.3559	AU aphelion
0.9833	0.8969	AU perihelion
	100	degrees from perigee, close approach earth orbit angle
1.00290	1.00290	AU Close approach radius
	1.07651	1+ecos()
1.7453	1.1858	radians at close approach
29.703	30.860	km/s tangential velocity
0.490	5.413	km/s radial velocity

	-1.156	km/s tangential difference
	-4.923	km/s radial difference
	13.215	degrees velocity angle from radial
	5.057	km/s total relative velocity
11.180		km/s Earth escape velocity
12.271		km/s Earth impact velocity
	4.29E+17	Joules impact kinetic energy
	4.18E+15	Joules per megatonne TNT
	103	MT TNT equivalent