You can certainly get the speed down enough so that the words impact crater wouldn't be in the report, also you smack them into oceans not land (though smacking them into the desert would be an option I guess if you could shed enough speed).

For a 10 meter sphere of nickel foam with a density of 2000kg/m3 (so about 60% 'air' by volume) it's ~2000 miles per hour[1].

http://hyperphysics.phy-astr.gsu.edu/hbase/airfri2.html#c5

Fast but not insurmountable.

That sphere would be ~8000 tonnes of pure nickel minus ablative losses (which would reduce the impact speed).

Of course you'd want the density to be below 1000KG/m3 or it'd sink.

So a 10m sphere at 850kg/m3 would have a terminal velocity of ~1300 miles per hour - or about mach 2 and you'd be picking up about 3500 tonnes of pure nickel bobbing about.

I'd quite like to see that actually (from a good distance away).

Stop thinking in terms of projectiles. Just because the Space Shuttle came down like brick in a controlled crash doesn't mean there are no other ways to do this. Without the need for ablation, btw!