Can someone tell me what this is?

A few weeks ago, my wife saw a flying object that didn't look like anything that she's seen before. She described it as the shape of a pool float. It was rectangular and flat in nature with rounded corners and huge. It was approximately the size of a tractor trailer and a metallic black color with a pattern on it (like a pool float). It was close enough that she was able to see it very clearly, and there was no writing, or identifying marks on it. She states that it was definitely moving horizontally and slightly descending under it's own power (no noise) that looked like approx. 50 - 60 MPH. She had a long time to try to figure out what it was because she spotted it from far away and the sky was clear as it passed within 1,000' ahead of her while she was at a red light. She even had time to snap a quick iPhone photo. Unfortunately the photo was not that clear, and the strangest part is that the photo doesn't represent what she described. However, we all know how an iPhone can change the image as it pixelizes, etc.
I asked a friend of mine that is an air traffic controller what he thought it was and without hesitation (without seeing photo), he said "weather balloon". I have a problem with that because I pulled up thousands of photos online of weather balloons, and I could not find a single one that looks even close to what she described. I also had a friend pull the aviation records of the air space at that location and time, and apparently the radar showed that there was an object at that place at that approximate speed and direction, however there was no communication with the tower. By the time it was directly where my wife saw it, it dropped off of the radar. I assumed that it was because it was too low at that point, since it descended slightly (she was guessing approximately 500' altitude.
Here is the kicker. On the same day, approximately 30 minutes later, there was a guy who took a photo by the south shore (approx. 20 miles away) and realized that there was a "UFO" in his picture, so he posted it on a UFO sighting web site. He said that he never saw it or heard it, but noticed it in his photo. Now for the really strange part......his picture looked EXACTLY like my wifes picture when I zoomed in to it!!!
Does anyone know what this object might be from my description, or the photo (I took a screen shot because I zoomed her original photo a little and screen shot it)? BTW, the speck in the photo that is below the object is just dirt on her windshield.
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Sounds like A good guess, but my wife said no way. She said it was so big and close and clear, that she would have seen the whole contraption that is powered and hanging below the parachute.
Any other ideas? I would love to figure out what it is because I have a friend that swears it's a UFO ( The Martian type, LOL), and I am of the thought that there is always a simple explanation that we are just not seeing. I really want to show him an object that looks like what was described so I can put this to rest!

 

The confusing part is that she is well aware of depth perception and distance, and is adamant about what she saw since it was very, very clear, and she had a very close view of the large object.