It is now a well-understood fact that Mars once had quite a bit of liquid water on its surface. In fact, according to a recent estimate, a large sea in Mars’ southern hemisphere once held almost 10 time as much water as all of North America’s Great Lakes combined. This sea existed roughly 3.7 billion years ago, and was located in the region known today as the Eridania basin. 

However, a new study based on data from NASA’s Mars Reconnaissance Orbiter (MRO) detected vast mineral deposits at the bottom of this basin, which could be seen as evidence of ancient hot springs. Since this type of hydrothermal activity is believed to be responsible for the emergence of life on Earth, these results could indicate that this basin once hosted life as well.

The study, titled “Ancient Hydrothermal Seafloor Deposits in Eridania Basin on Mars“, just recently appeared in the most prestigious scientific journal Nature Communications. The study was officially led by Joseph Michalski of the Department of Earth Sciences and Laboratory for Space Research at the University of Hong Kong, along with researchers from the Planetary Science Institute, the Natural History Museum in London, and NASA’s Johnson Space Center.

Together, this international team used data obtained by the MRO’s Compact Reconnaissance Spectrometer for Mars (CRISM). Since the MRO reached Mars in 2006, this instrument has been used extensively to search for evidence of mineral residues that form in the presence of water. In this respect, CRISM was essential for documenting how lakes, ponds and rivers once existed on the surface of Mars.

In this case, it identified massive mineral deposits within Mars’ Eridania basin, which lies in a region that has some of the Red Planet’s most ancient exposed crust. The discovery is expected to be a major focal point for scientists seeking to characterize Mars’ once-warm and wet environment. As Paul Niles of NASA’s Johnson Space Center said in a recent NASA press statement:

“Even if we never find evidence that there’s been life on Mars, this site can tell us about the type of environment where life may have begun on Earth. Volcanic activity combined with standing water provided conditions that were likely similar to conditions that existed on Earth at about the same time — when early life was evolving here.”

Today, Mars is a cold, dry place that experiences no volcanic activity. But roughly 3.7 billion years ago, the situation was vastly different. At that time, Mars boasted both flowing and standing bodies of water, which are evidenced by vast fluvial deposits and sedimentary basins.

The Gale Crater is a perfect example of this since it was once a major lake bed, which is why it was selected as the landing site for the Curiosity rover in 2012.

Since Mars had both surface water and volcanic activity during this time, it would have also experienced hydrothermal activity. This occurs when volcanic vents open into standing bodies of water, filling them with hydrated minerals and heat. On Earth, which still has an active crust, evidence of past hydrothermal activity cannot be preserved. But on Mars, where the crust is solid and erosion is minimal, the evidence has been preserved.

“This site gives us a compelling story for a deep, long-lived sea and a deep-sea hydrothermal environment,” Niles said. “It is evocative of the deep-sea hydrothermal environments on Earth, similar to environments where life might be found on other worlds — life that doesn’t need a nice atmosphere or temperate surface, but just rocks, heat and water.”

Based on their study, the researchers estimate that the Eridania basin once held about 210,000 cubic km (50,000 cubic mi) of water. Not only is this nine times more water than all of the Great Lakes combined, it is as much as all the other lakes and seas on ancient Mars combined. In addition, the region also experienced lava flows that existed after the sea is believed to have disappeared.

From the CRISM’s spectrometer data, the team identified deposits of serpentine, talc and carbonate. Combined with the shape and texture of the bedrock layers, they concluded that the sea floor was open to volcanic fissures. Beyond indicating that this region could have once hosted life, this study also adds to the diversity of the wet environments which are once believed to have existed on Mars.

Between evidence of ancient lakes, rivers, groundwater, deltas, seas, and volcanic eruptions beneath ice, scientists now have evidence of volcanic activity that occurred beneath a standing body of water (aka. hot springs) on Mars. This also represents a new category for astrobiological research, and a possible destination for future missions to the Martian surface.

The study of hydrothermal activity is also significant as far as finding sources of extra-terrestrial, like on the moons of Europa, Enceladus, Titan, and elsewhere. In the future, robotic missions are expected to travel to these worlds in order to peak beneath their icy surfaces, investigate their plumes, or venture into their seas (in Titan’s case) to look for the telltale traces of basic life forms.

The study also has significance beyond Mars and could aid in the study of how life began here on Earth. At present, the earliest evidence of terrestrial life comes from seafloor deposits that are similar in origin and age to those found in the Eridania basin. But since the geological record of this period on Earth is poorly preserved, it has been impossible to determine exactly what conditions were like at this time.

Given Mars’ similarities with Earth, and the fact that its geological record has been well-preserved over the past 3 billion years, scientists can look to mineral deposits and other evidence to gauge how natural processes here on Earth allowed for life to form and evolve over time.

It could also advance our understanding of how all the terrestrial planets of the Solar System evolved over billions of years.

Via UniverseToday

NASA is abuzz with the discovery of some utterly strange tube-like structures that were photographed on the surface of rocks by the Curiosity rover recently. These bizarre tubes, just a few millimeters in length, have sparked all sorts of speculation on what could have caused them.

“Meanwhile, back on Mars, I’m checking out these stick-like figures,” the Curiosity Rover’s official Twitter account tweeted on Jan. 3. “Each is about a quarter-inch long. Maybe they’re crystals? Or they could be minerals that filled spaces where crystals dissolved away. Stay tuned! Science continues.”

Nobody would notice these tiny tubes in the photos unless they were taking a very close look at them, which is what scientists did, leading to the discovery. Scientists aren't sure however if this is a geological or a biological find, like trace fossils from long-dead organisms that may have once lived on the Red Planet.

However, most experts seem to think that a mineral explanation is a far more likely one. Unfortunately, there’s really no way for us to learn more about it as Curiosity isn't equipped with the tools for closer examination, so for now it will have to be a mystery.

There’s no real rest for the rover. We planned sols 1921-1924 on December 22 and 29. Earlier, the team had planned a minimal set of activities for the rover to carry out over Sols 1913-1920, letting the science and engineering teams spend a bit of time away from work. However, this doesn't mean Curiosity was sitting idle. There were still plenty of things to do on Mars, including some automated ChemCam AEGIS observations. These activities automatically pick out targets of interest and measure their chemistry at our current parking spot.

On New Year’s Eve, the rover started carrying out the four-sol activity plan we completed Dec. 29. This site was so interesting that we backtracked to get to where the rover was parked for this plan. In the workspace in front of the rover, we have some very peculiar targets that warranted some additional interrogation. From orbit, this location has a very interesting appearance, with bluer hues being observed in High Resolution Imaging Science Experiment camera data on-board the Mars Reconnaissance Orbiter. On the ground, we are making Alpha Particle X-ray Spectrometer measurements on two targets, Haroldswick (the dark toned “stick”-like features observed in this Mastcam image from sol 1905) and the Raasay target.

We are using these observations to help characterize the interesting compositional variability observed at this location even further. We also planned several ChemCam activities to aid in understanding this ever-evolving compositional story Curiosity is unraveling. In all, while the science and engineering teams took some time off over the holiday season, Curiosity was hard at work on Mars.

Part of NASA’s Mars Science Laboratory mission, Curiosity is the largest and most capable rover ever sent to Mars. It launched November 26, 2011 and landed on Mars at 10:32 p.m. PDT on Aug. 5, 2012 (1:32 a.m. EDT on Aug. 6, 2012).

Curiosity set out to answer the question: Did Mars ever have the right environmental conditions to support small life forms called microbes? Early in its mission, Curiosity’s scientific tools found chemical and mineral evidence of past habitable environments on Mars. It continues to explore the rock record from a time when Mars could have been home to microbial life.

Curiosity explores Gale Crater and acquires rock, soil, and air samples for onboard analysis. The car-size rover is about as tall as a basketball player and uses a 7 foot-long arm to place tools close to rocks selected for study. Curiosity’s large size allows it to carry an advanced kit of 10 science instruments. It has tools including 17 cameras, a laser to vaporize and study small pinpoint spots of rocks at a distance, and a drill to collect powdered rock samples. It hunts for special rocks that formed in water and/or have signs of organics.

Curiosity carries the biggest, most advanced instruments for scientific studies ever sent to the Martian surface. The history of Martian climate and geology is written in the chemistry and structure of the rocks and soil. Curiosity reads this record by analyzing powdered samples drilled from rocks. It also measures the chemical fingerprints present in different rocks and soils to determine their composition and history, especially their past interactions with water.

Mars Science Laboratory arrived at Mars through technological innovations that tested a completely new landing method. The spacecraft descended on a parachute, then during the final seconds before landing, the landing system fired rockets to allow it to hover while a tether lowered Curiosity to the surface. The rover landed on its wheels, the tether was cut, and the landing system flew off to crash-land a safe distance away.

It is fit to climb over knee-high obstacles and travels about 100 feet (30 meters) per hour, depending on instrument activity, the terrain, and visibility its cameras have of the path ahead. The rover carries a radioisotope power system that generates electricity from the heat of plutonium’s radioactive decay. This electrical power source has already far exceeded its required operating lifespan on Mars’ surface of at least one full Martian year (687 Earth days). The generator provides greater mobility and flexibility in operating the rover regardless of season or sunlight. The steady flow of electrical power has enhanced the science payload capability and permitted consideration of landing sites at a greater range of latitudes than was possible on previous rovers.

Image Credits: 1.) NASA's Mars rover Curiosity captured this image on Jan. 2, 2018, with its Mars Hand Lens Imager (MAHLI). Using an on-board focusing process, the robot created this product by merging two to eight images previously taken by MAHLI, which is located on the turret at the end of the rover's robotic arm.

Image Credits: 2.) Curiosity Mastcam right image taken on Dec. 15, 2017.

Credit: NASA/JPL-Caltech/MSSS