File:Chesapeake Bay (MODIS 2019-03-17).jpg

English: The third largest estuary in the world and the largest in the United States, the Chesapeake Bay stretches about 200 miles (329 km) from Havre de Grace, Maryland in the north to meet the ocean at Virginia Beach Virginia. The broad waters, which cover about 4,480 square miles, separate the Delmarva Peninsula from the mainland and the watershed covers parts of six states (New York, Pennsylvania, Maryland, Delaware, Virginia and West Virginia).

The importance of the Chesapeake Bay can’t be underestimated. Not only does it support a diverse, unique, and vitally important natural ecosystem, it also provides food, recreation, economic wealth, and water for about 18.2 million people living in the watershed of the Bay. About 10 million of these (more than half) live near or on the shoreline.

The Chesapeake Bay was formed about 10,000 years ago when the massive glaciers of the last ice age melted and the rising ocean waters flooded the Susquehanna River Valley from present-day Virginia to north-eastern Maryland. The ancient river bed helps form a relatively deep trough along the bottom of the Bay, but the majority of the waters are surprisingly shallow, with an average depth of 21 feet (6.4 m).

The Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s Aqua satellite acquired a true-color image of the Chesapeake Bay on March 12, 2019.