Targeting cities with meteors

So this was done in Starship Troopers and I am curious if it is realistic for interplanetary warfare. The idea is that aliens launch meteors at major metropolitan areas...and it ends poorly for those cities...like, they're gone.

In this specific scenario aliens are using asteroids from our asteroid belt and launching them at earth to target specific cities. Never mind how they target (unless it is relevant to your answer) so accurately.

Given a city that meets these criteria:

• 450 sq miles of land area
• Generally flat land area, no more than 500 feet min/max elevation change

How large would a meteor have to be to wipe out a city that size and could it be done without having major regional impacts? Essentially I want a city destroyed but I don't want regional/global firestorms or cooling.

Yes or no, please show your work. The best answer will demonstrate the process and appropriate calculations for the scenario.

posted over 8 years ago

James‭

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