In a Facebook post, Zaki explained that scientific evidence confirms the presence of water on Mars approximately 3.7 billion years ago, in the form of rivers, lakes, and possibly an ocean that covered a third of its surface. This raises the fundamental question: Did Mars actually have an ocean? Previous doubts stemmed from the fact that previously mapped coastlines show variations in elevation of up to kilometers, contradicting the geological nature of coastlines, which should ideally be at roughly the same level.
The researcher pointed out that determining the presence or absence of oceans is crucial for understanding Mars' history and searching for traces of possible ancient life. Therefore, the research paper posed a different question, focusing on the "topographical footprint" left by the ocean on the planet's surface after it dried up, rather than relying solely on traditional coastlines.
The results, according to Zaki, revealed that the most visible signature of the oceans is not necessarily the beaches themselves, but rather the continental shelf, a vast area characterized by gentle slopes and low surface inclines. On land, this shelf is one of the largest sediment repositories and a vital record of climate and environmental evolution throughout geological time.
Zaki explained that the large variation in the heights of the supposed “shorelines” on Mars, which led some scientists to question the ocean hypothesis, finds a logical explanation when the focus shifts to the continental shelf. The continental shelf is not characterized by a fixed level, but rather its height and thickness naturally vary from one area to another, and may range between 100 meters and 1000 meters, which makes the observed topographical differences geologically expected and does not negate the existence of the ocean.
The Egyptian scientist confirmed that the study proves the existence of a huge and stable aquatic environment for a long period, which is a basic condition for the suitability of the environment for the emergence of life, stressing that the results do not prove the existence of life in itself, but rather establish the possibility of the availability of suitable conditions for it.
He pointed out that the next step requires moving from studying the shape of the ancient environment to directly searching for "biological indicators," which necessitates future missions and more precise tools to analyze geological materials in situ on the surface of Mars. Zaki concluded by noting that the mystery is not yet fully solved, and questions remain open, but this research represents a crucial step towards an accurate reconstruction of the history of the oceans on Mars and may provide a useful methodology for searching for ancient oceans on other planets.
