title: Calculating If 2 Circles On A Map Intersect
body: <p>I have 2 points on a map with an area around them (let's say 5 miles) and I need to figure out if they intersect. For example, imagine each point has a circle around them whose radius is 5 miles. I need to figure out if those two circles overlap. Can anyone point me to the math that can accomplish this?</p>
  
  <p>As an aside, I'm using Solr for other geospatial searches. Does anyone know if this can be accomplished with Solr?</p>
  
  <p>Thanks!</p>