Make sure simplejson is installed on your python path.
On oven, it's found in:
  /usr/lib/pymodules/python2.6
(which means it is already on the python search path)

Supernova API is at:
  http://supernova.astrometry.net/api

Nova API is at:
  http://nova.astrometry.net/api


Note on supernova:
  Since supernova is undergoing continuous development, consider your API
  key for it short lived and volatile.
  
  That said:
    If you find that the client is no longer able to connect to the
    (experimental) supernova API, please check that your API key hasn't
    changed by visiting http://supernova.astrometry.net/dashboard/profile/