The Curiosity rover found the largest number of organic molecules ever detected in Marte. The analysis revealed 21 different compounds in rocks collected on the red planet, seven of which were identified for the first time. The results were published in the scientific journal Nature Communications and reinforce the possibility that Marte harbored life in its distant past.
Descoberta history on Cratera Gale
Curiosity landed on Marte in 2012 on Cratera Gale with the aim of investigating signs of past life on the planet. Após After six or seven years of exploration, the rover reached the clay layers of Monte Sharp, a region called Glen Torridon where ancient lake rocks and river sediments have been preserved over billions of years. Local Nesse, Curiosity collected samples at a site called Mary Anning, named after the 19th-century British paleontologist.
The choice of location was carefully planned by the mission team. The clay layers have ideal properties for preserving organic molecules and indicate that water existed in Marte in the past, disappearing and reappearing in the same location over geological time.
Método unreleased chemical analysis
Pela first time, Curiosity performed wet chemical analysis directly on Marte. The rover excavated and crushed the rocks, loading the powdered samples into the Analisador of Amostras of Marte (SAM). The equipment dissolved the sample in a solution containing tetramethylammonium hydroxide (TMAH), a reagent capable of breaking down large molecules and identifying components that conventional methods cannot accurately detect.
Amy Williams, Universidade and Flórida professor who led the research, explains the importance of the technique:
- Compostos nitrogenous heterocyclics were first found in Marte
- Moléculas of benzothiophene were identified in the samples
- Sete of the 21 molecules had been undetectable until then
- TMAH can break down complex structures into their basic components
Conexão with the blocks of life
The molecules discovered include nitrogenous heterocyclic compounds, cyclic structures formed by carbon and nitrogen that function as precursors to the nucleic acids RNA and DNA. Esses are the carriers of genetic information in all known living organisms.
Benzothiophene, a compound containing carbon and sulfur, was also identified in the sample. Williams highlights that this same molecule is found in meteorites that impacted Terra and likely contributed to the origin of terrestrial life. The discovery suggests that identical compounds may have played a similar role in Marte billions of years ago.
Amazing Conservação
According to Williams, the organic molecules found have been preserved in Marte for approximately 3.5 billion years. Isso is particularly notable because the planet is exposed to intense bombardment of cosmic radiation, an environment that should destroy organic compounds relatively quickly.
The fact that large, complex molecules survived this hostile environment intact strengthens the theory that Marte, in its remote past, possessed the necessary conditions to sustain life. The planet may have had liquid water, a dense atmosphere, and protection from radiation — the essential elements that allow biological organisms to exist.
Confirmação in terrestrial laboratory
The team conducted validation tests on Terra using the Murchison meteorite, a space rock more than 4 billion years old discovered at Austrália in 1969. Quando subjected to the same TMAH reagent used on Marte, the meteorite decayed into components similar to those in the Mary Anning sample, including benzothiophene. Esse result reinforces the reliability of the Martian findings.
Williams points out that the same compounds identified in meteorites fell into Marte billions of years ago and also fell into Terra. Essas molecules likely constituted the fundamental building blocks that allowed life to emerge on the blue planet. The marine discovery provides indirect evidence that similar chemical processes could have occurred on the Red Planet.
Significado for astrobiology
The research expands knowledge about the prebiotic chemistry of Marte and reinforces arguments in favor of future missions that seek direct evidence of microbial life on the planet. The rover’s ability to perform sophisticated in situ analyzes has opened up new possibilities for geological and chemical investigations in extraterrestrial environments.
The results published in Nature Communications represent a milestone in Martian exploration, consolidating Marte as a priority target for the search for extraterrestrial life. The next phases of marine exploration should include more in-depth investigations of these molecular structures and their geographic distribution on the planet.