Normally, I try to stick to Io and the Jupiter system on this blog, but occasionally I do pay attention to what else is going on in the unmanned spaceflight community beyond Cassini/the Saturn system and the Jupiter system. Last week, the MESSENGER spacecraft performed its last of three flybys of the planet Mercury before it will go into orbit around the planet in 2011. In response to this flyby, I finally decided to piece together one of the global mosaics from last year's encounter, which covered similar territory.
This mosaic, consisting of 66 MDIS, narrow-angle camera images, was produced using a combination of ISIS3 (to calibrate and reproject each frame) and Photoshop (used to actually piece together each image). This mosaic could have been produced, I guess, entirely in ISIS3, but I found that trying to create a coherent control network that takes into account issues of camera twist angle and readily apparent range-to-target smear was a next to impossible task (I would like to apologize now to anyone trying to use Tethys in PIRL over the last few days while I was trying to create said control point network). The end result is the image you see at left.
Click Here to download the full resolution version of this mosaic. It would probably be best to just right-click and save the link as the full resolution version is a 20 MB PNG image file. Click the image above for a lower resolution version.
This mosaic is in orthographic map projection with a resolution of 0.6 kilometers (0.37 miles) per pixel. It is centered around 2 degrees South latitude, 322 degrees East longitude. The mosaic covers the eastern portions of the terrain covered by Mariner 10 in the 1970s as well as some terrain that wasn't revealed until the MESSENGER encounter on October 6, 2008. This terrain includes two ray craters at upper right and lower right that had previously only been seen in low-resolution RADAR data from Earth. The prominent ray crater just below and left of the center of the mosaic is Kuiper, previously observed by Mariner 10.
Some of the images from last week's encounter are slowly making their way to the MESSENGER home page, though versions that can be input into ISIS3 and converted into these huge mosaics won't hit the NASA PDS until sometime next year.
I hope you all enjoy this little treat. After I get some sleep, I will post more on some of the cool features you can find while searching around this mosaic. To be honest, my new favorite crater (at least on Mercury) has to be Rafael. In the morning, I will talk about why.
Image credit: NASA/JHUAPL/CIW/Jason Perry