The High Resolution Imaging Science Experiment (HIRISE) is currently flying onboard the Mars Reconnaissance Orbiter (MRO) mission. HIRISE stands for High Resolution Imaging Science Experiment and is as its name states is an extremely high-resolution camera sensing the visible spectrum and manufactured by Ball Aerospace and Technologies Corporation, Boulder CO. A picture of this camera is shown to the right. NASA's Mars Reconnaissance Orbiter was launched from Cape Canaveral in 2005 with the purpose to "search for evidence that water persisted on the surface of Mars for a long period of time".

HiRISE will also assist in the evaluation of candidate landing sites. By combining very high resolution and signal-to-noise ratio with a large swath width, it will be possible to image large areas on a variety of scales down to 1 meter resolution, greater than that of previous landers. As a result of its polar orbit, HIRISE will be able to offer such views over any specified region of Mars. HIRISE is also capable of capturing stereo image pairs. These will be acquired over the highest-priority locations with a vertical precision of better than 25 cm per pixel.

NASA promises on its mission website that data and user-friendly web tools will be available to the public to view HiRISE images. So far this seems to be true, but kudos go to the University of Arizona HIRISE web site, not NASA. The University is the operator of the HIRISE camera (which is only one of six sensors on board the MRO which include two other cameras, a spectrometer, a ground penetrating radar and a radiometer). They have generously posted over 10,000 high-resolution images in their catalogue, each one of stunning resolution and equally fascinating. Any of these images can be studied online or downloaded. They offer the friendly IAS viewing tool that is capable of handling the .jp2 file format. It is also possible for the public to submit observation requests.

The easiest way to view the data is to visit the website and browse the catalogue. Clicking on a thumbnail leads you to a data page that will give you information regarding the image and several choices for downloading files and renderings of various resolutions. The easiest way to examine reduced scale images is to browse down to the Wallpaper files. These are offered in .jpg format that can be read by any image viewing utility. The image is offered in .pdf format as well.

If you click on the color image on the data page you will be presented with a rendering of the full swath, of which the displayed image is a subset. The full images are available for download as well. They are very large files, the largest over 1GB in size. The full images are archived in jp2 format. Common image viewers like PaintshopPro cannot open such images but the HIRISE website offers the IAS Viewer for free download that is capable of viewing either local (downloaded) or remote (on the HIRISE website) images. The latter is particularly useful as you do not have to download the image in order to view it in detail.

Although HIRISE imagery covers only a small fraction of the Martian surface, there is a lot to learn by studying this excellent resource, both for the professional and the amateur. If you wish you can even join a Planetary Society needle-in-a-haystack effort to locate failed Mars landers. (See their website if you wish to participate). It will also be interesting to see the first terrain renderings from the instrument as DEMs become available from the stereo pairs. A rendering of one of the few so far created (courtesy of the USGS) is shown to the right. A few more are available at the USGS Planetary GIS webserver. The corresponding MOLA image shown as an inset to the image indicates the vast improvement in resolution afforded by HIRISE. The available resolution is seldom available for earthly DEMs!

The stated purpose of HIRISE and the MRO is the search for water and ultimately for signs of Martian life. It seems clear that water does exist on Mars (although not normally in liquid form due to the very low temperatures and low atmospheric pressure.) It is possible that transient water exists as a result of periodic heating and melting of underground ice. This liquid water may be forced to the surface and may create perennial (perhaps once only) flow channels on the Martian surface. Many of these possible canyons (some rather large) are evident in HIRISE imagery. Rather than flowing to an ocean or inland salt sea like on earth, the water may quickly sublime, literally disappearing into thin air. Whether this actually occurs and whether life can somehow sustain itself during these brief and probably violent and localized moist events remains to be discovered. Regardless, the impressive HIRISE Mars images provide a fascinating look at this most interesting of our solar system neighbors.