The Mars rover Curiosity drove 6.2 feet (1.9 meters) during the 100th Martian day, or sol, of the mission on November 16, 2012 in this panoramic image courtesy of NASA. The rover used its Navigation Camera after the drive to record the images combined into this view. (Photo : Reuters/NASA Handout)
A new study has revealed that the water found on Earth and the water that once ran on Mars likely came from chondritic meteorites that impacted the planets during early formation.
In order to find those results, scientists from the Carnegie Institution for Science analyzed the composition of two Martian rocks that collided into Earth as meteorites. The study found that the two planets began forming in similar ways but eventually drifted in their evolution, Space.com reported.
The study's results contradict previous beliefs that terrestrial planets obtained water from comets. Scientists now believe that water came from chondritic meteorites, which "contain small, granular minerals that become integrated into the planets they land on," according to Space.com.
In a statement, John Jones, an experimental petrologist at NASA's Johnson Space Center, explained, "These meteorites contain trapped basaltic liquids, not unlike the basalts that erupt on Hawaii. They are pristine samples that have sampled various Martian volatile element environments."
According to redOrbit, one meteorite studied did not show any changes from the Martian mantle up to the surface of the Red Planet, while the second meteorite "appears to have sampled Martian crust that had been in contact with the Martian atmosphere."
Study leader, Tomohiro Usui, a former postdoctoral researcher at NASA's Lunar and Planetary Institute in Houston, said, "There are competing theories that account for the diverse compositions of Martian meteorites. Until this study there was no direct evidence that primitive Martian lavas contained material from the surface of Mars."
The differences in hydrogen isotopic compositions found in the two meteorites led the group of researchers to conclude that water on Mars' surface has a different geologic history than water from Mars' interior, redOrbit reported.
Conel Alexander, of Carnegie's department of terrestrial magnetism, said, "The hydrogen isotopic composition of the water in the enriched meteorite clearly indicated that they have been overprinted, so this meteorite tells scientists more about the Martian crust than about the Martian mantle. Conversely, the other meteorite yields more information about the Martian interior."
Alexander added, "To understand the geologic history of Mars, more information about both of these environments is needed."
The study will be published in the December issue of Earth and Planetary Science Letters.