The Mars Curiosity rover has hit the proverbial jackpot in its quest for signs of potential life in the Red Planet’s past– discovering strong evidence that liquid water once flowed over the surface.
The mineral composition of white veins found coursing through the rock in Mars’ Gale Crater suggest that water once flowed through the surrounding fissures. In addition, abundant berry-shaped spherules indicate that water formed and worked over the sedimentary concretions. The rover has also found evidence that, over long periods of time, water rounded out the sharp edges of large grains within the rocks.
“[It] turns out to be kind of the ‘jackpot’ unit,” says John Grotzinger, NASA Curiosity’s mission’s chief scientist of the California Institute of Technology. “It is literally shot through with these fractures and vein fills.”
The rocky stretch of Martian land that the rover is now exploring, named Yellowknife Bay, “is literally shot through with these fractures,” says John Grotzinger, geologist at the California Institute of Technology in Pasadena., California, and chief scientist of the mission. “Basically these rocks were saturated with water,” he added.
Mission scientists originally thought they might have to wait until Curiosity reached the slopes of nearby Mt. Sharp before finding such evidence of flowing surface water, and were excited to happen upon what Grotzinger described as a “jackpot unit.” If the team did make a similar corroboratory finding on Mt. Sharp, “we would have been absolutely thrilled,” he added.
The one-ton Curiosity rover has covered slightly more than a quarter mile since landing last August, but despite this seemingly slow progress has relayed a wealth of data back to Earth and made many exciting discoveries, including an unusual flower-like rock that is still puzzling scientists.
Employing an array of 10 instruments and a seven-foot robotic arm, the craft has already transmitted 18,226 images and nearly 10 gigabytes of raw information about the planet’s geology, mineral chemistry, soil composition, and atmosphere. The most recent effort undertaken by the rover involves sending its powerful impact drill through the surface of Mars for the first time.
Designed to penetrate about 2 inches into the Red Planet’s subsurface, the rover’s drill will extract a small portion of powdered rock, which will then be analyzed using an onboard chemistry kit. The process may require six weeks or more, according to Curiosity’s team, in an environment where repairs and replacement parts are hundreds of thousands of miles away. NASA engineers will have to exercise extreme caution in their operations, lest the Martian rock damage the drill bit, or the mineral sample become contaminated by leftover bits of Earth when the rover scoops it onboard.
Yellowknife Bay has proven to hold numerous clues to a possible watery past. A wide variety of rock textures, ranging from “conglomerate to sandstone to siltstone,” indicate surface activity of water, Aileen Yingst, a researcher with the Planetary Science Institute in Tucson and deputy principle investigator for the robotic hand lens, known as MAHLI, told ABC News. All were “sedimentary rocks, meaning that other rocks had to be broken down into fragments and transported elsewhere,” Yingst continued.
In addition, a rocky outcrop dubbed the Shaler Unit suggests small sediment dunes were shifted by an ancient stream flowing through the area. Relatively high levels of hydrogen within the newly discovered white veins, consisting mostly of calcium sulfate, further confirm the hypothesis that water flowed through the fissures.
The recent findings follow the discovery in recent weeks of the “Black Beauty” meteorite, a two-billion-year-old piece of Martian rock found in the Moroccan Sahara that contains more evidence of water than any other known Martian rock sample.
Curiosity’s explorations may or may not ultimately find definitive evidence of either water or life on Mars, but the recently discovered white veins provide a fresh reason to believe that both may have existed in our planetary neighbor’s past.