[AlexanderHowl]

Tungsten heats up too quickly for that to be effective (it needs only .11 J/K/g, meaning that its higher melting temperature only matters if it does not keep heating up). Iron, by comparison, takes four times as much energy to heat up, and has a decent melting temperature and a decent density. A 10 meter long by 1 meter wide rod with a 10 meter long conical cap would mass around 80 meter and would hit with 800 metric tons of force (a third less than a similar tungsten rods). In addition, iron is everywhere on the moon, so you can just make spikes by the millions and use mass drivers to launch them from the moon.