The Mars Express Orbiter has captured images of a huge crater full of ice on the surface of Mars, just in time for the holiday season.
The European Space Agency’s (ESA) Mars Express mission was launched back in June 2003 and entered orbit around the red planet in December of the same year. Since then, the probe has been surveying the surface of Mars using a high resolution camera as well as other tools like radars and spectrometers. The discovery of water beneath an ice cap on Mars earlier this year was a major achievement which stemmed from data collected by the mission.
Now the orbiter has captured images of a huge crater, measuring 51 miles across and located in the northern lowlands of Mars. Although it might look like the crater is full of snow, it is actually full of water ice, and scientists estimate that the ice must be 1.1 miles thick in the center. They believe that the crater will remain full of ice all year round, due to a phenomenon known as a “cold trap.” This is where the deepest parts of the crater contains ice which cools air as it moves over it. The cooled air then sinks downwards, creating a layer of cold air above the ice which acts like a shield and keeps the ice stable, preventing it from melting due to its insulating properties.
The image of the crater is a composite of five different images, each of which was captured by an instrument on the Mars Express Orbiter called the Mars Express High Resolution Stereo Camera (HRSC). The images were first captured at the start of the year, and with each each orbit of the planet the orbiter was able to capture another piece of the image. The five images were then combined into one to create the photo shared by the ESA.