On March 23, 2013 the Mars 2001 Odyssey spacecraft completed 50,000 orbits around the Red Planet. If it's not a mixed metaphor to call a solar-powered robotic orbiter a workhorse, then Mars Odyssey is a serious contender for the title of Workhorse of the Solar System. In December 2010 Odyssey broke the previous record to become the longest-working spacecraft at Mars.
In addition to mapping the planet, Odyssey also serves as a crucial communication link, relaying signals between Earth and several rovers as they land and drive on the Martian surface.
Since the spacecraft entered orbit in October of 2001, the teams managing Odyssey's thermal emission imaging system have captured nearly 670,000 images in visible and infrared light. Those images provide an outstanding overview of even the far reaches of the Red Planet. Countless thousands of craters and canyons are captured as long swaths of terrain in the pictures Odyssey sends down. There are so many great views, in fact, that it can be hard to narrow them down. The images below have one thing in common: they all lie roughly along the same line running from the north pole to the south pole of Mars, at 256 degrees east longitude. This line crosses the terraced ice fields of the north polar cap, through the deep troughs of Tantalus Fossae, up the towering volcanic slopes of Ascraeus Mons, down into the twisted maze of Noctis Labyrinthus, across the plains of Syria Planum and Phoenicius Lacus, before finally crossing into the complex formations at the south polar ice cap.
Including that entire journey in pictures would make for an impossibly long page, so I've only included some of the highlights, arranged from north to south.
Even so--prepare to scroll!
The Great White North
The edge of the north polar ice cap and the northern plains of Mars, seen by the Mars Odyssey orbiter.
Analyzing Ascraeus Mons
A swath across the great mountain, Ascraeus Mons, as seen by the Mars Odyssey orbiter. The caldera of the extinct volcano is visible near the center. On the flanks, collapse pits where underground lava tubes have collapsed. This is a "decorrelation stretch image," which includes four panels showing the same part of the Martian surface. In each panel, the differences between views captured through different camera filters has been intentionally maximized in order to highlight the variations in surface composition. These are obviously not the colors you'd see with your eyes, but help Mars scientists explore the landscape.
A long stretch of Martian landscape, starting in the north with a section of the Noctis Labyrinthus region of Valles Marineris. This view comes from the heat radiated by the rock, and captured by the thermal emission imaging system on board the Mars Odyssey orbiter.
The Southern Reaches
A section of the layered south polar ice cap on Mars, as captured in detail by the Mars Odyssey orbiter.
This treasure trove of data and images will only grow as Mars Odyssey and the people who fly it continue to add to their long years of work.