Last update: October 17th, 2019 at 9:00 am
Part of the astronaut experience is recognizing and photographing the same place under completely different conditions—most often in daylight and at night. Over repeated orbits and multiple flights, astronauts become adept at merging both visions of the planet.
The same astronaut probably took both of these photographs of the port city of Haifa on Israel’s Mediterranean coast. In geography training, astronauts are taught to concentrate on the shapes of coastlines because they are a first-order visual cue when circling the planet, and often uniquely shaped. The nose of Cape Karmel and the bay that protects the Port of Haifa are shapes that can tell crews where they are.
In the daylight image, the strong visual line of the coast contrasts with the subtle city colors. The steep slope of the north flank of Mount Carmel (bottom of the image), facing the port, is marked by a long, dark shadow in the mid-afternoon sunlight. Shorter shadows indicate several steep-sided canyons that cut into Mount Carmel. Older neighborhoods with linear roads lie on the lower slopes, closer to the port. Newer neighborhoods show a pattern of streets that wind along the intricate edges of the canyons. In a small country where land is scarce, brown farmlands appear close to the middle of the city.
The night shot does not show the coastline, unless you know where to look for it. But it does show different city neighborhoods in a way that is difficult to see in the day. The brilliant port lights contrast with somewhat dimmer residential areas. Straight roads of the older residential neighborhoods are easily distinguished from the winding roads that follow the canyon cliffs. The industrial area just east of the port has areas of green and blue lights and a less dense street pattern. Surrounding farmlands are so dark that they can be confused with the sea.
Credit: Astronaut photograph ISS046-E-1292 was acquired on December 14, 2015, with a Nikon D4 digital camera using a 500 millimeter lens. Astronaut photograph ISS045-E-148262 was acquired on November 29, 2015, with a Nikon D4 digital camera using a 400 millimeter lens. Both 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 members of the Expedition 46 and Expedition 45 crews. The images 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 U., Jacobs Contract at NASA-JSC.