[stametseater]

I think rods from gods is oversold. The classic version of this is a "telephone pole of tungsten", or something along the lines of a 6 meter long cylinder, 0.3 meters across, which works out to 0.42 cubic meters of tungsten, which would be just over 8000 kilograms. If you do the math, rods coming in at orbit speeds are barely worth talking about; the actual rods from god USAF proposal had these tungsten telephone poles starting in orbit and impacting the ground at merely 3 km/s, equivalent to 11 tons of TNT.

Faster then: the kinetic energy of such a mass moving at 12 km/s, faster than escape velocity, would be 'only' 137 tons of TNT, approximately 1/15th of the 2020 Beirut explosion. Even if you throw the rods into the ground at a blistering 50 km/s, that only gives you the equivalent kinetic energy of 2.4 kilotons of TNT, or 1/6th of the Little Boy nuclear bomb.

Then there are the terminal effects; such a tungsten rod is basically an oversized armor piercing dart like tanks shoot at each other. It will drive itself straight into the ground and most of the rod's kinetic energy will be spent pulverizing bedrock and itself. Such a weapon would be great for taking out bunkers, but I think very wasteful for any other purpose.

[justinclift]

> It will drive itself straight into the ground and most of the rod's kinetic energy will be spent pulverizing bedrock and itself. Such a weapon would be great for taking out bunkers, but I think very wasteful for any other purpose.

Wonder if it could be precision enough for non-military applications? eg possibly faster for deep geothermal drilling than using the existing surface based borehole drilling approach.

For military applications though, it'd wonder if such a rod (or small sequence of them) could be effective when striking geological fault lines. eg the San Andreas Fault line

Aka the old "use the terrain" approach.