The Outer Hebrides, a chain of more than 100 islands, lie off the northwest coast of Scotland’s mainland. Stretching about 200 kilometers (120 miles) from north to south, the islands are known for their rugged terrain, white sand beaches, and hardy sheep.
On an unusually cloud-free day in September 2024, the OLI (Operational Land Imager) on Landsat 8 captured this image of the archipelago, which bounds the western extent of Scotland. According to the country’s nature agency, the Norse may have named the islands “Havbredey,” meaning “isles on the edge of the sea.” The Hebrides have been shaped by the maritime climate of the Atlantic Ocean, with its heavy rainfall and strong winds.
Although the Outer Hebrides consist mainly of rocky terrain, the shorelines of Harris and North Uist islands have distinctive white sandy beaches, made of washed-up shell fragments and sediment from glacial erosion. Farther inland, low-lying grassy plains (known as machair), blanket bogs, marshes, and saline lagoons cover the islands. Glacial valleys on the Isle of Lewis, the northernmost and largest of the islands, were carved by the movement of ice sheets and meltwater during the last ice age.
Much of the archipelago’s 26,000 residents live on either Lewis or Harris islands. Lewis attracts tourists to its Calanais Standing Stones monument, erected on the western coast of the island 5,000 years ago. The tall stones are arranged in a cross shape and predate England’s famous Stonehenge.
By some estimates, sheep outnumber people on the island chain. Several breeds of sheep have adapted to the wet, windy climate and rough terrain. Wool from these hardy sheep is used to make Harris Tweed, a well-known fabric spun and handwoven in the Outer Hebrides. Much like a wine made from grapes grown in Bordeaux, France, only cloth that has been woven in mills on Harris or Lewis islands can be called Harris Tweed.
NASA Earth Observatory image by Michala Garrison, using Landsat data from the U.S. Geological Survey. Photograph of Harris island's Seilebost beach by Paolo Chiabrando, Unsplash. Story by Emily Cassidy.
