universetoday | This movie was created using an imagery from Mars Express’ High
Resolution Stereo Camera (HRSC). The images are normally taken looking
straight down (nadir), and the video combines topography information
from the stereo channels of HRSC to generate a three-dimensional
landscape, which was then recorded from different perspectives, as with a
movie camera, to render the flight shown in the video.
Korolev Crater is 82 kilometers (50 miles) across and at least 2 km
(1.25 miles) deep. This well-preserved crater is located the northern
lowlands of Mars, just south of a large patch of dune-filled terrain
that encircles part of the planet’s northern polar cap (known as Olympia
Undae).
That’s not snow you’re seeing, but this crater is constantly filled
with water ice, and its central mound is about 1.8 kilometers (1.1
miles) thick all year round. It’s one of the largest reservoirs of
non-polar ice on Mars.
This view reminds me of a flight I took where I flew over Meteor
Crater in Arizona USA. But for comparison, Meteor Crater is less than a
mile across (.737 miles/1.186 km) and just 560 feet (170 m) deep.
You may be thinking, how can this ice remain stable in Korolev Crater;
doesn’t water ice sublimate away in Mars thin atmosphere? Just like dry
ice does here on Earth, water ice on Mars usually goes from solid to gas
with the low atmospheric pressure. (Mars has approximately 8 millibars
while on Earth the average, atmospheric pressure at sea level is 1013.25
millibars, or about 14.7 pounds per square inch.)
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