[AZLiberty]

Here's another back-of-the-envelope way of looking at the energy in one of those tungsten rods. The energy comes from converting chemical energy (from rocket fuel) into potential energy (by being at a certain height above the earth) and kinetic energy (going at a certain speed). A Saturn V rocket has about 1,000 tons of fuel. If 100% of that were converted into potential and kinetic energy, at 100% efficiency, of a single tungsten rod, then the rod could potentially have the energy of one kiloton of fuel, perhaps equivalent to one kiloton of TNT.

There are huge efficiency losses, however. First, using rocket fuel to create kinetic energy is not 100% efficient -- I'm guessing 50%. That takes us down to half a kiloton energy equivalent. Second, one rod weighs about 15,000 lbs or 7.5 tons. The cargo capacity of the Saturn V is about 130,000 lbs, or about seventeen tungsten rods. So each of the rods can have at most 1/17 of the energy from the rocket fuel. Now we're down to about 30 tons of rocket fuel equivalent energy per tungsten rod. Of course a huge amount of energy was wasted lifting the Saturn V and its fuel into space, though most of it not all the way into space. I'll take the energy total down to 10 tons of rocket fuel per tungsten rod, combining the kinetic energy of orbital speed and the potential energy of being 100 miles above the earth's surface. Neglecting energy losses from re-entry, this is the energy available to create chaos when the rod hits the earth.

This 10 tons of energy is focused onto a 1-foot diameter area. This is the equivalent cross-section of about 2,000 .22 caliber bullets. A .22 cartridge has about 1/10 ounce of powder in it. With our tungsten rod, we have the equivalent of 10 tons behind 2000 bullets or about 10 pounds of powder/rocket fuel behind each of the bullets, compared to the usual 1/10 ounce. That is, each bullet-equivalent area of the tungsten rod has about 1600 times the energy of an actual bullet, and the tungsten rod has the area of 2000 bullets, so the tungsten rod has the energy of about 3 million bullets coming at you.

Depending on the depth of the target, I imagine the tungsten rod has a pointed titanium tip so the energy is focused on a much smaller cross-section than 1 foot across.

That's going to hurt.

[grey_whiskers]

http://hyperphysics.phy-astr.gsu.edu/hbase/gpot.html

[Axenolith]

The orbiting rod already has Kinetic energy equal to about 15000 mph (orbital velocity) plus the potential of being ~300+ miles above the gravity well. Merely adjusting course contributes part of the 9.8 m/s2 gravity component.

Once you noodle out the final velocity it’s all E=MC2

If the mass is 18000 pounds
Velocity 17,500 MPH

The energy delivered will be
184,278,953,567.31 ft/lbs

Which is equal to a rats ass under 60 tons of TNT