In our recent post about LIGO and other large scientific instruments we mentioned that the Large Hadron Collider (LHC) at CERN in Geneva, Switzerland is underground. We know that it is circular and we were able to identify several buildings on its circumference. We would have liked to use that to draw a circle showing the location of the LHC. However, Google Earth does not have an option to draw circles. There are a number of tools on the web that will create a circle, given the coordinates of the centre and a radius, but in this case we don’t know where the centre is.
The results are not very accurate so if anyone knows a better algorithm for finding the centre of a circle on the surface of the Earth please let us know in the comments.
To create a circle simply create a KML file with three placemarks, upload it below and click ‘Create Circle’.
To create a circle that you know the centre of, create a placemark at the centre and name it ‘centre’ and create a second placemark on the circumference. Then upload it above and click ‘create circle’.