No, this is not possible. You can only order on actual field values, the term weight would require a JOIN to a non-field table and EFQ is not capable of doing that.

You will have to create a manual SQL query to do this. Note that Drupal by default maintains the node &lt;-> term associations in the taxonomy_index table, that one is easier and more reliable to query than a field data table.

Get term weight in node object for ordering with EntityFieldQuery
An article about the recent release of a large number of confirmed exoplanets states that most of the 715 newly announced exoplanets orbit very close to their host stars. 

Do the theories predict that this is a representative sample and that most planets are very close to their host stars? Or is it just that our current detection techniques are predisposed to finding only those planets close to their stars (because the sensors look for dimming of the host star for example)? 
