A Story of Mars, Tito and a Global Monument to Unity

Just a couple of days ago, I just happened to be looking for a fun science documentary to watch before going to bed. In this search, I came across a new episode of the PBS science show NOVA about the new rover that recently landed on the planet Mars [you can watch the documentary at THIS YouTube link]. What is unique about this mission is that the spot where they landed the Mars rover, named “Perseverance”, was within a crater that, many eons ago, was a lake with rivers leading into and out of it. The incredible mission of this Mars rover that it will undertake is to probe the soil of his ancient lake bed for signs of possible signs of prehistoric Martian life. However, one peculiar aspect of this episode that I found interesting, but which was never remarked upon in the episode (and the reason I am writing this article here), is the name which was given to this crater where the Perseverance rover landed: “Jezero Crater”.

A photo of Jezero Crater on Mars. Credit: NASA/JPL/MSSS/ESA/Justin Cowart
A computer animation showing the Perseverance Rover on the surface of Mars. Credit: NASA

While I am by no means fluent in the languages used in the former-Yugoslav region, I am familiar enough with them to know that “Jezero” means “lake”, and being that the crater was stated to be an ancient lake, it became immediately clear to me that there was undoubtedly some nature of connection to that region that was not being mentioned in the episode. After doing some research, I discovered that the crater was named in 2007 by the International Astronomical Union (IAU), which commonly uses the names of small towns around the world when naming craters. In this instance in 2007, the IAU came up with a list of 80 potential names for the crater, with the most popular being “Jezero”, which, in this case, was a small town in western Bosnia & Herzegovina (BiH), just a few kilometers south of Mrkonjić Grad. Numerous sources relate that the reason "Jezero" was chosen was because the name of the village was so closely related to the historical geology of the Martian crater. However, upon the Jezero Crater being named in 2007, this decision was not immediately known in BiH or the village of Jezero. It was not until Jezero Crater was subsequently chosen as the landing site for the Perseverance rover Mars mission 11 years later in 2018 that people in BiH began to notice. A Feb. 2021 Balkan Insight article explains how the mayor of the town of Jezero, Snežana Ružičić, was very surprised by this decision (not even believing it at first), and was even more incredulous when NASA and the American Embassy in BiH organized a viewing party for the town’s school children when the Perseverance rover land on Mars on February 18th, 2021. The municipality of Jezero hopes that this distinction will draw more visitors from around the world to this small village (as it is among the poorest regions of the country), as well as to BiH in general. A large sign has now been erected in the center of the village of Jezero announcing the connection of the Martian rover to this small community.

A recent photo of the small village of Jezero, BiH. Credit: DataScience/Tonuh
A recent photo of the sign in Jezero, BiH talking about the Martian rover. Credit: CoolIn Sarajevo

An additional key feature of the town of Jezero, BiH that connects it to the features of the Martian crater is that it sits on the edge of a large lake, “Plivsko Jezero”, while also having a significant river running right through the center of the town, the “Pliva River”. Mentioning the Pliva River brings us to an important, and often overlooked, component to the Jezero Crater. While much press is given to the crater’s name “Jezero” and the town it is named after, I have found very little mention in the popular press of the names given by the IAU to the now-dry inflow and outflow river valleys (or “vallis” as they are called on Mars) characterizing Jezero Crater: Una Vallis, Sava Vallis, Pliva Vallis and Neretva Vallis. Any keen geographer will immediately recognize these as four of the major rivers that dominate the landscape of Bosnia & Herzegovina and, thus, the area of Jezero Crater became an ever greater monument to the cultural heritage of the country, marking not just one small town within the nation, but also some of its most important geographical features. Of these four named valleys, there is one particular one that unquestionably holds the most significance in respect to not only its sheer size, but also because it is on the alluvial plain at the opening of this valley that NASA plans to land its Perseverance rover… and that is the Neretva Vallis. It is quite curious as to why "Neretva" was chosen as the name of the primary river valley feeding Jezero Crater, as in the village of Jezero itself in BiH, it is the Pliva River that goes through the center of the community. However, within the Jezero Crater, the name "Pliva" is given to a much smaller and less conspicuous valley.

A view of Jezero Crater on Mars showing many of its marked geological features. Credit: NASA

So, such a matter begs the question, what was the reason behind the most significant of valleys of Jezero Crater (and the NASA mission in general) getting dubbed with the name “Neretva”? When it comes to river valleys that are emblematic and highly symbolic for the heritage and history of Bosnia & Herzegovina, the Neretva is unquestionably among the most iconic. During the Yugoslav-era, the name “Neretva” was synonymous with the daring military maneuver pulled off by Partisan commander Josip Broz Tito in the early days of March 1943 during WWII. With his back to the wall at Jablanica on the west side of the Neretva River and pursued by an army of Axis troops, Tito came up with an idea of tricking his adversaries into thinking that he was heading north towards Bugojno along the west banks of the Neretva. To achieve this clever deception, Tito and his MOG unit destroyed all the bridges across the Neretva River from the towns of Jablanica to Prozor, thus convincing Axis forces that Tito was trying to prevent Axis interception as he marched north on the east side of the river. Axis troops subsequently took this bait and headed north as well, all while Tito and his +10,000 troops (many of which were wounded soldiers), created a precarious makeshift crossing over the ruins of the destroyed partially-submerged bridge at Jablanica and instead headed eastwards towards safety in the direction of the Drina River. This daring and dramatic episode became one of the most popular and captivating historical moments not only of the Battle of Neretva, but also of all of Tito’s actions during WWII. During the Yugoslav-era, you could not mention the Neretva River without bringing to mind in the listener Tito's famous wartime exploit. With this cultural history in mind, it stands to reason that perhaps one of the motivations behind labeling this most important and significant valley at Jezero Crater as “Neretva” might very well be related to this iconic and legendary WWII event. As Tito dove down into the Neretva Valley on Earth to save the lives of those under his command, NASA's Perseverance rover dives down into the mouth of the Neretva Vallis on Mars in search of the answer to the mystery of life in our solar system.

A WWII-era photo of Yugoslav Partisans crossing the Neretva River Valley on makeshift bridge.
A photo taken by Perseverance rover of the landscape of Jezero Crater taken in Feb. 2021. Credit: NASA

However, there may be other factors to consider when looking at the naming of Jezero Crater and its inflow and outflow valleys. Firstly, when the name “Jezero” was given to the crater in 2007 by the IAU, it can probably be assumed that not a terrible amount of thought went into how the name might be culturally interpreted, not only within BiH, but also the many other countries around the region that use the word “jezer