Day: 26

Today, my team of researchers and I explored the Hár crater of the moon Callisto. Hár Crater is a part of a heavily cratered region on Callisto. It is 50km (30mi), and it’s a double ringed crater. We are still unsure what causes a double ringed crater; nothing is for certain. Scientists have come up with a few hypotheses, however. For instance, double ringed craters may have been where two asteroids have hit the surface of a planet or moon in the same spot. Another guess is that ice buildup underneath the planet has caused a raise in the surface of a crater, creating another ring inside of it. These could both be possible explanations; Callisto not only has a heavily cratered surface, which could prove the first hypothesis right, but it also has a possibility of an icy ocean underneath its surface, which could prove the second theory true. In Hár’s cratered region, there are many other craters, and many of them are much wider and longer than Hár. However, we found it necessary to explore Hár out of all of the craters because of it’s perplexing raised mound in the middle of it.

The environment was mainly the same as anywhere else on the moon. It was heavily cratered, with landslides. The landslides tended to be around 3-3.5 diameters in length. These landslides occur when the crater’s wall fails, due to too much pressure from gravity, leaving a mound of a rocks. We had to trek across the inside of the first part of the crater to reach the raised mound inside. We are still investigating the possibilities of the double crater’s formation. There was many landslides inside the crater as well, as the crater was 50km, after all. That meant that our journey across the crater to investigate it was a long one!

The weather is a little different out here on Hár. It’s freezing, especially since we’re surrounded by a mound that is potentially made out of ice. We’re lucky our spacesuits keep us so warm. The temperature tends to get to around -139 degrees Celsius on average. In the morning, however the temperature tends to rise to -108, which is why we usually tend to do our work and research bright and early. The nights cool down to -193, which is why our research lab is made out of a synthetic fabric that captures a lot of heat. Callisto’s atmosphere is extremely thin, so unfortunately it doesn’t hold heat very well. It’s always cold out here!

Hár Crater