8 Minutes Total time, repeatable on failure 10-15? mins, 3? hours on success, ease of quest tricky, do not land on shards for updates, harvest them while flying, aggro may throw you into combat and knock you off mount and fall to death easily = fail, long flight back to update area. Mini memory and locate game, will be tough for those that have little or no short term recall, if you have good short term recall and navigational skills this is easy.
Click anywhere on the shard to start. ( 973, 325, -838 ) /waypoint 973, 325, -838
Fly to highlight area on map, click on 5 large floating bits of the Aetherscar, you will know which ones when you get close enough and the mouse over changes from a pointer to hand/clicky. Watch out for aggro, avoid if you can. IMPORTANT: remember the order which ones you clicked in sequence. (Also each run picks diff clickable shards so locs are worthless, I think) Mini memory game deal.
Fly to the area highlighted in water to find the broken bits of Aetherscar fairly large and easy to see. May have to swim to get some of the updates. 5 of them needed.
Fly back to the previous 5 and click them again, you have to click them in the order you first clicked them, they will not be clickable till you do them in sequence, recall note in step 2!