The shock of the ‘Chicxulub’ meteorite in the Yucatan peninsula 66 million years ago triggered the disappearance of the dinosaurs, despite marking a milestone in the history of science and ending the Cretaceous period, it was not the first planet to suffer a disaster of this caliber. Mars also recorded the impact of an asteroid similar to the one that hit EarthInstead, it triggered a ‘megatsunami’ when it still had seas of liquid water in its territory.
In 1976 the first probe to successfully operate on the red planet was expected to land on water, instead it touched down on a area covered with rocks difficult to determine.
A study carried out by the Autonomous University of Barcelona (UAB), the Planetary Science Institute and the NASA Ames Research Center has revealed that the Viking 1 probe touched down right on the sediments generated by an ancient ‘megatsunami’‘. “These stratigraphic relationships suggest that a marine impact probably formed the crater,” they have highlighted in the study.
They have also stressed that the shock of this asteroid, between 3 and 9 km in diameter, formed the place where the probe launched by the United States landed more than 40 years ago. Specific, Viking 1 touched down in the lower section of Maja Vallesa massive channel formed by catastrophic river floods about 3.4 billion years ago in the Chryse Planitia region.
The arrival of the probe would have taken place in the correct place to look for signs of life in soil samplesas suggested by the study led by researchers Alexis P. Rodríguez, from the Planetary Science Institute, and María Zambrano and Mario Zarroca, from the UAB.
The research has been published in Scientific Reports and its objective is the identification of an oceanic crater and simulations of the wave generated by the impact of the asteroid.
The images generated by the probe, on the other hand, they did not highlight signs of past flooding Therefore, it was concluded that the sedimentary deposits were composed of mantles of ejecta. These were caused by meteorite impacts or degraded lava flows, but notor there were craters derived from the shock or abundant lava fragments.
“Our simulations show that the megatsunami was devastating and that initially reached a wave height of 250 meters and flooded coastal areas located at least 2,000 km from the impact crater. These coastal areas include a huge basin where the wave could have formed an inland sea in the tropics of the planet“, explained Zarroca.
“The search for Martian marine craters is extremely difficultbut it is essential to understand the evolution of coastal environments on the red planet”, added Rodríguez.
Researchers have emphasized that the crater is above the landscapes formed by the floods generated by the ocean and covered by the deposits of the most recent ‘megatsunami’ that they have already mapped.
“It is possible that it contains a geological record detailing the evolution of the ocean from its formation to its freezing“, Rodríguez has suggested. NASA stated at the time that there was no evidence that there were signs of microbiological life on Mars in the soil near the landing.
This study, however, brings to light a new geological context in which astrobiological information is reconsidered collected in the first in situ measurements on Mars. It will also make it possible to determine new land and study its potential habitability conditions.
“If it is verified that the salts detected on the ground were of marine origin, it would be possible predict a brackish composition of seawater which would have been much more resistant to freezing than terrestrial seas”, Zarroca has argued.
“This type of composition exists in some lakes on Earth and these contain organisms capable of living in extreme environments. If the ocean formed an ice sheet, this saline composition could have lengthened its liquid state significantly, stabilizing its habitability.”
From the UAB they have remarked that the next step is to characterize terrain close to the crater as possible landing sites based on their potential for habitability and for harboring evidence of ancient biosignals.