Here is a rudimentary solution using Phantom.js, which grabs a screen shot of an area of the webpage and outputs it to a file.

var page = new WebPage();
 page.viewportSize = { width: 1920, height: 1080 };
 //the clipRect is the portion of the page you are taking a screenshot of
 page.clipRect = { top: 450, left: 660, width: 470, height: 300 };
  page.open('http://www5b.wolframalpha.com/input/?i=flights+seen+from+current+geoIP+location',
    function (status) {
     just_wait();
       });

  function just_wait() {
     setTimeout(function() {
             page.render('planesoverhead.png');
             phantom.exit();
     }, 6000);
 }

I will update a more well thought out code in a few days that will grab the planes+overhead gif by element ID and save it as a whole.

The planes+overhead result gif changes size based on the total number of planes overhead at any particular time, meaning that a fixed resolution may not always include the full results.

Hi David,

Most probably it is impossible to get this data using Wget but you have two possibilities:

1) Try to automate you browser in such a way that it will save this image or take a screenshot of what the browser displays.

2) Try free Mathematica Player. I cannot say for sure but this free application probably can access Wolfram|Alpha in the way shown in my previous answer. If it can, you can retrieve the data and take a screenshot of what is displayed in the player (the free version does not allow Exporting).

Hi David,

You don't need Wget for this, just get the map from Wolfram|Alpha using Mathematica directly:

skyMapImage = WolframAlpha["flights overhead New York", {{"SkyMap:FlightData", 1}, "Image"}]

Or you can get this image in vector form and then Export it as GIF or PNG with the resolution you want:

skyMap = WolframAlpha["flights overhead New York", {{"SkyMap:FlightData", 1}, "Cell"}]

Export["skymap.gif", Rasterize[skyMap, "Image", RasterSize -> 1000]]

(As you see, there are unfortunately some artifacts due to FrontEnd rendering bugs. I'm using version 10.3.1.)