Sorting geopoints in array

curl -XPUT 'http://localhost:9200/twitter'

curl -XPUT 'http://localhost:9200/twitter/tweet/_mapping' -d '{
	"tweet" : {
		"properties" : {
			"pin": {
				"properties": {
					"location": {
						"type": "geo_point"
					}
				}
			}
		}
	}
}'

curl -XPUT 'http://localhost:9200/twitter/tweet/1' -d '{
"message" : "Locations",
"pin": {
"location": [[60,20],[50,20]]
}
}'

curl -XGET 'http://localhost:9200/twitter/tweet/_search' -d '{

    "sort" : [
        {
            "_geo_distance" : {
                "pin.location" : [60, 20],
                "order" : "asc",
                "unit" : "km"
            }
        }
    ],
   "query": {"match_all": {}}
}'