Feel free to file this one under amusing. You know those balloons Google started releasing into the stratosphere several years ago in an experimental attempt to expand Internet access? Apparently a certain Android app is able to pick them up. A reader submitted these screenshots of Flightradar24 tracking one of Google's Project Loon balloons.
In this case, the helium balloon was spotted hovering somewhere off the coast of Brazil at an altitude of 53,600 feet. At 7 mph, it wasn't moving very quickly, but it only takes a quick glance at the picture to be reminded of why.
Google's balloons don't show up on all flight trackers. We tried a couple, and none had any luck. But there's a chance Flightradar24 isn't the only one. Chime in if you stumble across something yourself.
Tracking balloons from Flightradar 24 is apparently already a long-established hobby, with images shared regularly in certain circles on Google+. Feel free to jump in on the fun.