JavaScript - Looping and Adding Key Value Pair to JSON Object

I am trying to sort the "response", a JSON object passed through a function from the API, and insert the "img:" key and the src value of the image based on the planet name.

What I tried: I tried using response.push as shown in several StackOverflow links, but this just adds the key value to the entire object as a separate value. I also tried [i ]'s answer, but it doesn't look like my console is giving me an error.

Several links that I have visited . They are useful, but don't seem to refer to the loop sequence I will be after.

• Adding key value pair to json object
• How do I add a key / value pair to a JavaScript object?
• JS JSON Pair Key and Value

Any help or guidance would be appreciated.

  app.controller('mainCtrl', function($scope, parseService) {

  $scope.getParseData = function() {
    parseService.getPlanet().then(function(response) {

      for(var i = 0; i < response.length; i++)
        if (response[i].name === "Hoth") {
          console.log("We found hoth!");
          response.push({'img': 'testpic.jpg'}); //Trouble w. this line
        } else {
          console.log("not Hoth");
        }
        $scope.planets = response;

    });
  }
  $scope.getParseData();

});