Last update: August 21st, 2019 at 2:00 am
While orbiting over the Gulf of Alaska and moving toward the west coast of the United States, an astronaut aboard the International Space Station shot this panorama looking north into the snow-covered landscape of Canada’s Coast Mountains, the Canadian Rockies, and Vancouver Island. Numerous dark valleys contrast with the brilliant snow, even in the low light of a northern winter. The valleys were eroded by glaciers repeatedly in various ice ages over the past 2 to 3 million years.
Low stratus clouds mask the 250-kilometer (150-mile) wide plateau between the mountain ranges. Above these clouds, a long cloud band slants across the image. Meteorologists think this may be the remnants of a jet stream cloud band. Such jet stream bands indicate the general position of these fast “rivers of air.” Based on its northeast orientation, its altitude, and its linear appearance, the cloud band is in the typical position and orientation of the Polar Jet, which blows northeast towards Hudson Bay, then dives south over the southeastern provinces of Canada. Animated maps of the Polar Jet for the days before this image show a dying branch of the jet over western Canada.
Even in this distant view, several thin contrails appear, disrupting the jet band and showing where aircraft flew in and near the jet stream. Aircraft take advantage of these fast jets (which can reach speeds of more than 440 kilometers or 275 miles per hour) as tail winds that can shorten flight times.
Images taken just before and just after this image show changing view angles of the jet stream cloud, giving a sense of the astronaut experience of flying across the planet. The arc of lower-level clouds on the far left is a cold front approaching Vancouver Island.
Astronaut photograph ISS046-E-3699 was acquired on December 29, 2015, with a Nikon D4 digital camera using a 28 millimeter lens, and is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by a member of the Expedition 46 crew. The image has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by M. Justin Wilkinson, Texas State U., Jacobs Contract at NASA-JSC and M. Trenchard, Barrios Technology, Jacobs Contract at NASA-JSC.