Much of the city of New Orleans remains flooded four days after Hurricane Katrina battered the Gulf Coast.

NASA’s Terra satellite took both of these images within the last week, one before Katrina’s storm surge flooded New Orleans (top) and the other afterwards.

On Aug. 27, 2005, New Orleans appeared as a tan and green grid wedged between Lake Pontchartrain  and the Mississippi River to Terra’s Moderate Resolution Imaging Spectroradiometer (MODIS).

By Aug. 30, 2005, water flooded buildings and streets of New Orleans (bottom) after levies failed. North of the city, Lake Pontchartrain and Lake Maurepas swelled into almost a single body of water.

Both images were taken in false color to easier separate water and land. Water appears black, or dark blue where covered by mud, and vegetation shows as green. Clouds appear as white and light blue.

-- SPACE.com Staff

Credit: Jeff Schmaltz, MODIS Land Rapid Response Team at NASA GSFC.