I was spending Memorial Day weekend in the Long Island area and was in New York City visiting the USS Intrepid Sea, Air, and Space Museum. After touring the deck and interior of the museum I made my way to the adjacent dock to see the nearby Concorde on display. It was New York Fleet week so there were multiple News and Tour Helicopters flying up the Hudson and a Coast Guard MH-65 helicopter performing a Search and Rescue demonstration over the water, there was also the normal commercial airliner traffic always seen in the area, with all this going on I had my eye on the sky anyway when I noticed another object that I didn’t recognize, At first I thought it was a Balloon, but upon closer visual inspection it appeared much larger than a balloon and was a different overall shape, and despite the noticeable wind that day the object appeared to be hovering in place or moving extremely slowly. It’s color was also strange, it seemed to be mostly a metallic grey or chrome color, It was mostly circular in shape from my perspective. I estimated the objects altitude to be at around 4,000 feet more or less because it was noticeably higher than the various helicopters going up the Hudson but considerably lower than the passing commercial airliners, I had no way to estimate the objects size due to its distance, and the lack of anything close enough to it to compare it with. After a few minutes the object began moving slowly and gradually increased it’s speed. I began taking photos on my camera phone (an IPhone 5) and began backing up to get a better view of the object before it passed over the deck of the Intrepid and out of my sight. The following day I uploaded the photos onto my computer and reviewed them. The object was barely visible in the photos, but I cropped them to get a closer view of the object. The first few photos showed exactly what I described seeing, a small rounded metallic grey object hovering, However the 6th photo showed that the object clearly had a shaded edge to it proving it was an actual three-dimensional object. An uneven pattern began to develop where the object was completely shiny in one picture and then has a darker shaded edge in the next few, I could not explain if this was due to the sun shining on the object or not. However it was the 11th picture when I noticed things were becoming stranger. In this photo the original color and possibly even the shape of the object has significantly changed. On close visual analysis the photo shows the object as a definitively structured craft with a more angular shape to it, and a small ring of light around the center, something I did not notice while viewing the object (though I may have missed it through the phone lens). The final photo is by far the strangest, and most compelling, The object is again grey/chrome and metallic but the upper part appears to be a brighter blue-white color which may be reflective light or light generated by the object itself. I will submit all of the cropped, close-up photos and some of the original ones. There were no other witnesses that I ran into, although I find it unlikely that I was the only one who saw the object because there were hundreds of people on the museum deck and neighboring docks (not to mention the general area of Manhattan) I did point out the object to my father who was unable to see it well at the distance and quickly dismissed it as probably being a balloon, however after I showed him the photos he no longer thought that. I have always been intrigued by the UFO phenomenon and know a lot about aviation and identifying aircraft, so all I can say is that the object I saw and photographed did not resemble or move like any normal airplane or helicopter I have seen before.