This Envisat radar image is centred on the man-made Raystown Lake in the US state of Pennsylvania.
The lake is a popular place for camping, biking, hiking, boating, fishing and other water activities.
Some believe that this lake is home to a Loch Ness Monster-like creature – ‘Raystown Ray’. There are stories of boaters seeing large, dark objects just below the water’s surface, and some even claim to have seen a head and long neck emerge from the water.
Whatever it might be, the locals believe that Ray is somewhat shy and likely to be a vegetarian.
Near the top of the lake – which appears as a snaking red and blue line in this image – there is a bright white radar reflection from the Raystown Dam. The dam provides hydroelectricity and flood control.
The area pictured is part of the greater Valley and Ridge Appalachians, in the Appalachian Mountain range. The lines that cut through the image are the long, even ridges characteristic of this region. One of the significant ridges is Tuscoarora Mountain in the lower-right corner.
Millions of years ago, the rocks in this region were flat, but pressure from the southeast compressed them in a northwesterly direction. This motion caused them to fold into the ridges and valleys typical of the Appalachian range. The shape of the valleys has been emphasised by further erosion by water.
This picture is a compilation of three images from Envisat’s radar on 23 December 2007, 2 March 2008 and 11 May 2008.
This image is featured on the Earth from Space video programme.