HAARP is a favorite target for conspiracy theorists. It's an easy target because the science behind it is rather difficult to understand and even harder to explain to people with no background in science. So I'm starting this thread to: A) Gather useful resources that can help explain what HAARP actually does and how it does it B) Explain why HAARP can NOT do the various things that are claimed (change the weather, create earthquakes, mind control). First a very brief attempt at an understandable explanation of what HAARP does: About 60 miles up the atmosphere is very thin. The radiation from the sun here is so powerful it knocks electrons off the air molecules creating an ionized layer called the ionosphere. HAARP is square grid of antenna that transmit radio waves straight up. The radio waves are absorbed by the electrons in the ionosphere. This heats them up slightly (but a lot less than the normal heat from the sun). HAARP does not affect the 60 miles of atmosphere below the ionosphere. Scientists do experiments by heating a small patch of the ionosphere in various ways and observing the results. They do this mostly because variations in the ionosphere affect radio communication, and they want to study this so they can improve radio communication. (obviously still not very understandable of most non-scientific people) The first places to start is the official HAARP web site and FAQ. Here I've bolded the key numbers [Updated Aug 2018 with new web site] https://www.gi.alaska.edu/haarp/frequently-asked-questions-faq The following comes from the old web site: https://web.archive.org/web/20130518010959/http://www.haarp.alaska.edu/haarp/tech.html A more detailed explanation, with more key facts, is found here: https://web.archive.org/web/20130202021127/http://www.haarp.alaska.edu/haarp/ion4.html Details of the actual power use: https://web.archive.org/web/20130116094952/http://www.haarp.alaska.edu/haarp/factSheet.html More helpful facts: (https://web.archive.org/web/20130330214012/http://www.haarp.alaska.edu/haarp/ion5.html) The last bit is rather an exaggeration, as the most powerful radio station ever, Radio XERA, was less than 1.0 MW (far in excess of what is allowed now for radio transmission), and TV towers only get into the hundreds of kilowatts.