With its myriad of canyons, unusual rock formations and ancient lakebeds, Utah is a geologist's playground. This true-color image of Utah was acquired on June 20, 2000, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA’s Terra spacecraft.
The dark aquamarine feature in the northern part of the state is the Great Salt Lake. Fourteen thousand years ago, the Great Salt Lake was part of Lake Bonneville, which covered much of northern and western Utah. The extent of the lakebed can be seen in light tan covering much of northern and western Utah and extending into Idaho. (Click for more details on the history of Lake Bonneville.)
Other remnants of Lake Bonneville include the Great Salt Lake Desert (the white expanse to the left of the Great Salt Lake) and Lake Utah (the lake to the south of Salt Lake City). The white color of the Great Salt Lake Desert is due to the mineral deposits left by Lake Bonneville as it drained out into the Snake River and then proceeded to dry up.
The dark bands running through the center and northeastern part of the state are the western edge of the Rockies. The dark color is likely due to the coniferous vegetation that grows along the range. The tallest mountains in the Utah Rockies are the Uinta Mountains, which can be seen in the northeastern corner of the state bordering Colorado and Wyoming. The white fishbone pattern in the center of the Uinta Mountains is snow that hadn’t yet melted.
To the southeast, one can see the reddish-orange rocks of the northernmost section of the Colorado Plateau. Utah’s well-known desert attractions, including Arches National Park, Canyonlands National Park, and Glen Canyon, are located in this region. The long, narrow lake is Lake Powell, created after the construction of Glen Canyon Dam in the 1950s.
The Great Salt Lake of northern Utah is a remnant of glacial Lake Bonneville that extended over much of present-day western Utah and into the neighboring states of Nevada and Idaho approximately 32,000 to 14,000 years ago. The north arm of the lake, displayed in this astronaut photograph from April 30, 2007, typically has twice the salinity of the rest of the lake due to impoundment of water by a railroad causeway that crosses the lake from east to west. The causeway restricts water flow, and the separation has led to a striking division in the types of algae and bacteria found in the north and south arms of the lake.
Great Salt Lake serves as a striking visual marker for astronauts orbiting over North America. A sharp line across its center is caused by the restriction in water flow from the railroad causeway. The eye-catching colors of the lake stem from the fact that Great Salt Lake is hypersaline, typically 3–5 times saltier than the ocean, and the high salinities support sets of plants and animals that affect the light-absorbing qualities of the water. Space Station astronauts have recorded the decline in lake levels in response to a regional 5-year drought taking both detailed views and broad views of the entire lake. As lake levels have declined the salt works have become islands in the middle of a dry lakebed.