NASA’s Rover Found a Lost River System Under Mars, And It Changes What We Know About Its Past

Another surprising revelation about Mars' geologic past has been brought about by the Perseverance Rover developed by NASA: an underground river delta predating another, currently observable delta within the Jezero crater. The discovery is based on the use of ground-penetrating radar, which allowed researchers to study geological features below the surface of sediments and rocks in the region.

The significance of this finding does not lie solely in confirming the previous existence of water; it is more important for the presence of layers and cycles of river delta systems, which imply several stages of flow rather than a single period. Ground-penetrating radar helped identify layers of sediment that resemble those formed on Earth due to the slowing of the flow and deposits left on its way. As per studies cited by Scientific American and NASA references, this reveals that Mars was characterized by relatively constant climatic and other conditions supporting flowing rivers for a long period.

This discovery alters how the past climate history of Mars can be interpreted. Scientists used to believe in limited or periodic occurrences of liquid water activity, but the discovery implies cycles and periods of disappearance and re-emergence of the liquid substance.

What Do the Layers Reveal About Mars?

One of the most telling pieces of evidence is the inner architecture of the buried delta. With the help of radar imaging technology, scientists can see individual sedimentary layers indicating different periods of water flow and deposition. This information shows that Jezero Crater was formed not by a single river flow, but by several flows, with dry periods in between. The surface observations also support this conclusion. Fan-shaped deposits identified on images taken with the help of Perseverance's Mastcam-Z resemble those that appear on the planet Earth when rivers converge into lakes or oceans. These types of deposits provide an excellent environment for storing organic materials, as water accumulates there slowly.

Further confirmation is provided by the detection of minerals such as kaolinite in the bleached rocks on Mars' surface. Kaolinite is a mineral that occurs on Earth under favorable conditions of constant warmth and humidity. In addition to indicating the occurrence of a lake at some point, this finding also proves that water had enough time to interact with rocks. It appears that Mars was not a temporarily wet planet, but rather one experiencing cycles of liquid water formation.

This Changes the Search for Life

Not only does the finding of the buried delta add to the geological narrative of Mars, but it also helps in finding traces of life. The presence of several river deltas means that there is a higher likelihood that organic compounds can be found, since deltas are the best places to preserve biosignatures because of the accumulation of matter brought into them by the flowing rivers. The existence of numerous layers with biosignatures gives researchers an opportunity to conduct research on a variety of times in history.

Additionally, meteorite studies corroborate this theory, as evidenced by the detection of hydrogenous minerals in rocks on Mars that imply that hydrological processes occurred on a large scale throughout the planet.