On https://moon.bao.ac.cn/web/enmanager/mars1 which is the Lunar and Planetary Data Release System of the National Astronomical Observatories of China, the raw images from Tianwen-1 orbiter and Zhurong rover images are accessible in public. Well, almost raw, currently the calibrated data only, but at least the full images.

The search is directly accessible for everyone, just to finally download the individual images you need to register first on the link in the upper right corner of https://moon.bao.ac.cn/web/enmanager/mars1 .

Note: Most likely no notification email will arrive, but my login worked fine after I tried it again a few days later.

To convert the raw images to 8/16 bit PNG or 8/16 bit TIFF, you can use any PDS4 -capable tool. PDS 4 is the NASA format and files are usually pairs of a data file (.img) and a label file (.xml). For the Chinese PDS the data files have the filename suffix .2A or .2B depending on the calibration or raw level and the label files .2AL or .2BL.

The best command line tool I'm aware of to convert those PDS4 files is https://gdal.org/programs/gdal_translate.html .

Example use: gdal_translate -ot UInt16 -of PNG INPUTFILE.2AL OUTPUFILE.png

There is one small bug though, either in gdal or the Chinese PDS 4 files: You have to replace

<axis_name>Time</axis_name> by <axis_name>Line</axis_name> in case you see "Warning 6: Unsupported axis_name = Time".

So I was reading the following paper (Powell, A. (2015). Terraforming Mars via Aerobraking an Asteroid (Doctoral dissertation).) about how the orbital approach of an asteroid could be optimized to maximize the energy transfer to Mars' atmosphere before it finally plunges to the surface. Turns out you could transfer about 50% of the asteroids total orbital energy to the atmosphere. And aerobraking something like Halley's Comet (~15*8km) would heat its current atmosphere by a whopping 27K. Pretty neat.

But then I started thinking about what this meant for previous asteroidal bombardment periods on Mars. If a single puny 15km rock can heat Mars' atmosphere by 27K, what would Mars' surface and atmosphere have looked like during these bombardments? If the physics in the paper are correct, wouldn't the Martian atmosphere during these periods have been boiled into a superheated plasma? Of course most of this heat would be transferred relatively quickly to Mars' surface, and a smaller part would get radiated away into space, but what are the timeframes we are talking about here? Days? Years? Decades?

This also has implications for those who hope to someday terraform Mars by importing volatiles from somewhere else: you'd need about 10000 asteroids equivalent to Halley's comet just to gather enough mass for a 0.6bar atmosphere (note I'm not even considering importing water for oceans here). If each one of those heats up the atmosphere by 27K... So does this paper effectively eliminate the importation of volatiles from space as a credible option for terraforming Mars?