Chicago, Illinois, is the third-largest city in the United States, and it shows clearly as a spidery gray mass on the southewestern end of Lake Michigan in this true-color Aqua MODIS image acquired May 5, 2005. The city itself covers 228 square miles, but take into account its suburbs (called "Chicagoland"), the size jumps to over 5,000 square miles, which is what helps it show up in satellite imagery like this. The city originally sat on swampy land around the mouth of the Chicago River, but over the years building efforts have raised the city's ground level by four to seven feet.
Out in the deep blue waters of Lake Michigan, a bright plume of calcium carbonate curls along the eastern shore. This is a common occurence - the lake experiences a "whiting effect" nearly every summer.