Astronauts aboard the International Space Station took these midwinter panoramas of the St. Lawrence River in eastern Canada. The seaway crosses the scene from lower left to top right in the daytime photograph. Clouds mask the river’s full width where it widens into the Gulf of St. Lawrence (top right). This major river connecting the Great Lakes to the Atlantic Ocean is practically invisible in the night image, with only two lines of small town lights to indicate its shorelines.
The night image does show the city of Montreal as a major cluster of lights. Night lights also make it clear that the provincial capital, Quebec City (population 770,000), is smaller than the Montreal metropolitan area (population 3.8 million). Neither city stands out visually in the daytime photograph.
In the top image, dry, cloudless air is moving southeast and picking up moisture as it streams over the St. Lawrence River. The moisture appears as numerous tendrils of cloud that stream out into the Atlantic Ocean. A long cloud streamer also rises from Lac Saint-Jean, although the lake is nearly iced over.
The night image shows that the lake is ringed by small settlements. It also shows a distant green aurora and airglow on the horizon. Part of the horizon is broken up by a darkened ISS solar panel (upper right)
The circle of the Manicouagan impact crater appears in the daytime image. You can view close-ups of the crater here and here.
Astronaut photograph ISS042-E-83031 was acquired on December 30, 2014, with a Nikon D4 digital camera using a 26 millimeter lens. Astronaut photograph ISS042-E-160966 was acquired on January 20, 2015, with a Nikon D4 digital camera using a 19 millimeter lens. Both images are provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The images were taken by the Expedition 42 crew. Both have 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 University, Jacobs Contract, at NASA-JSC.