Author Topic: Mars Rover Curiosity  (Read 54008 times)

BridgeTroll

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Re: Mars Rover Curiosity
« Reply #210 on: June 02, 2017, 07:27:45 AM »
https://mars.jpl.nasa.gov/news/2017/curiosity-peels-back-layers-on-ancient-martian-lake

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'Curiosity Peels Back Layers on Ancient Martian Lake'
06.01.2017



Fast Facts:
-- NASA's Curiosity Mars rover mission has provided an unprecedented level of detail about an ancient lake environment on Mars that offered favorable conditions for microbial life.
-- A lake in Mars' Gale Crater long ago was stratified, with oxidant-rich shallows and oxidant-poor depths.
-- The lake offered multiple types of microbe-friendly environments simultaneously.

A long-lasting lake on ancient Mars provided stable environmental conditions that differed significantly from one part of the lake to another, according to a comprehensive look at findings from the first three-and-a-half years of NASA's Curiosity rover mission.
Different conditions favorable for different types of microbes existed simultaneously in the same lake.
Previous work had revealed the presence of a lake more than three billion years ago in Mars' Gale Crater. This study defines the chemical conditions that existed in the lake and uses Curiosity's powerful payload to determine that the lake was stratified. Stratified bodies of water exhibit sharp chemical or physical differences between deep water and shallow water. In Gale's lake, the shallow water was richer in oxidants than deeper water was.



"These were very different, co-existing environments in the same lake," said Joel Hurowitz of Stony Brook University, Stony Brook, New York, lead author of a report of the findings in the June 2 edition of the journal Science. "This type of oxidant stratification is a common feature of lakes on Earth, and now we've found it on Mars. The diversity of environments in this Martian lake would have provided multiple opportunities for different types of microbes to survive, including those that thrive in oxidant-rich conditions, those that thrive in oxidant-poor conditions, and those that inhabit the interface between those settings."
Whether Mars has ever hosted any life is still unknown, but seeking signs of life on any planet -- whether Earth, Mars or more-distant icy worlds -- begins with reconstruction of the environment to determine if it was capable of supporting life.
Curiosity's primary goal when it landed inside Gale Crater in 2012 was to determine whether Mars has ever offered environmental conditions favorable for microbial life. In its first year, on the crater floor at "Yellowknife Bay," the rover found evidence of ancient freshwater river and lake environments with all the main chemical ingredients for life and a possible energy source for life. Curiosity has since driven to the base of Mount Sharp, a layered mountain inside the crater, and inspected rock layers that grow progressively younger as the rover gains elevation on lower Mount Sharp.
Differences in the physical, chemical and mineral characteristics of several sites on lower Mount Sharp at first presented a puzzle to the rover team. For example, some rocks showed thicker layering with a larger proportion of an iron mineral called hematite, while other rocks showed very fine layers and more of an iron mineral called magnetite. Comparing these properties suggested very distinctive environments of deposition.
Researchers considered whether these differences could have resulted from environmental conditions fluctuating over time or differing from place to place.
"We could tell something was going on," Hurowitz said. "What was causing iron minerals to be one flavor in one part of the lake and another flavor in another part of the lake? We had an 'Aha!' moment when we realized that the mineral information and the bedding-thickness information mapped perfectly onto each other in a way you would expect from a stratified lake with a chemical boundary between shallow water and deeper water."
In addition to revealing new information about chemical conditions within the lake, the report by Hurowitz and 22 co-authors also documents fluctuations in the climate of ancient Mars. One such change happened between the time crater-floor rocks were deposited and the time the rocks that now make up the base of Mount Sharp were deposited. Those later rocks are exposed at "Pahrump Hills" and elsewhere.
The method the team used for detecting changes in ancient climate conditions on Mars resembles how ice cores are used to study past temperature conditions on Earth. It is based on comparing differences in the chemical composition of layers of mud-rich sedimentary rock that were deposited in quiet waters in the lake. While the lake was present in Gale, climate conditions changed from colder and drier to warmer and wetter. Such short-term fluctuations in climate took place within a longer-term climate evolution from the ancient warmer and wetter conditions that supported lakes, to today's arid Mars.
"These results give us unprecedented detail in answering questions about ancient environmental conditions on Mars," said Curiosity Project Scientist Ashwin Vasavada of NASA's Jet Propulsion Laboratory, Pasadena, California. "I'm struck by how these fascinating conclusions on habitability and climate took everything the mission had to offer: a set of sophisticated science instruments, multiple years and miles of exploration, a landing site that retained a record of the ancient environment, and a lot of hard work by the mission team."
In mid-2017, Curiosity is continuing to reach higher and younger layers of Mount Sharp to study how the ancient lake environment evolved to a drier environment more like modern Mars. The mission is managed by JPL, a division of Caltech in Pasadena, for NASA's Science Mission Directorate, Washington. Curiosity and other Mars science missions are all part of ambitious robotic exploration to understand Mars, which helps lead the way for sending humans to Mars in the 2030s. For more about Curiosity, visit:
https://www.nasa.gov/curiosity
https://mars.nasa.gov/msl/

In a boat at sea one of the men began to bore a hole in the bottom of the boat. On being remonstrating with, he answered, "I am only boring under my own seat." "Yes," said his companions, "but when the sea rushes in we shall all be drowned with you."

BridgeTroll

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Re: Mars Rover Curiosity
« Reply #211 on: July 13, 2017, 07:36:40 AM »


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07.11.2017
Mid-2017 Map of NASA's Curiosity Mars Rover Mission

This map shows the route driven by NASA's Curiosity Mars rover, from the location where it landed in August 2012 to its location in July 2017, and its planned path to additional geological layers of lower Mount Sharp.

The blue star near top center marks "Bradbury Landing," the site where Curiosity arrived on Mars on Aug. 5, 2012, PDT (Aug. 6, EDT and Universal Time). Blue triangles mark waypoints investigated by Curiosity on the floor of Gale Crater and, starting with "Pahrump Hills," on Mount Sharp. The Sol 1750 label identifies the rover's location on July 9, 2017, the 1,750th Martian day, or sol, since the landing.

In July 2017, the mission is examining "Vera Rubin Ridge" from the downhill side of the ridge. Spectrometry observations from NASA's Mars Reconnaissance Orbiter have detected hematite, an iron-oxide mineral, in the ridge. Curiosity's planned route continues to the top of the ridge and then to geological units where clay minerals and sulfate minerals have been detected from orbit.

The base image for the map is from the High Resolution Imaging Science Experiment (HiRISE) camera on the Mars Reconnaissance Orbiter. North is up. "Bagnold Dunes" form a band of dark, wind-blown material at the foot of Mount Sharp.

The scale bar at lower right represents one kilometer (0.62 mile). For broader-context images of the area, see PIA17355, PIA16064 and PIA16058.

In a boat at sea one of the men began to bore a hole in the bottom of the boat. On being remonstrating with, he answered, "I am only boring under my own seat." "Yes," said his companions, "but when the sea rushes in we shall all be drowned with you."

BridgeTroll

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Re: Mars Rover Curiosity
« Reply #212 on: September 13, 2017, 08:39:24 AM »
https://mars.nasa.gov/msl/mission/mars-rover-curiosity-mission-updates/

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Sol 1814: Spectacular views
Written by Rachel E. Kronyak on 09.12.2017


As we've seen from the past several weeks and months of imaging, Curiosity's approach to and ascent of the Vera Rubin Ridge (VRR) has provided us with stunning views of the Mount Sharp terrain. Our parking spot after this weekend's drive was no exception, seen in the Navcam image above. In today's plan we are continuing our trek up the lower strata of the VRR and have no shortage of multi-colored bedrock targets to image and analyze.

Today we planned two sols. On Sol 1814, we planned a touch-and-go (APXS analysis + full suite of MAHLI images) on the dark bedrock target "Pumpkin Nob." Additional science block activities include a corresponding ChemCam raster and Mastcam image of Pumpkin Nob. We'll also perform a multispectral Mastcam observation on "Weymouth Point," a region of VRR terrain just ahead of Curiosity. Following a drive, we'll take our standard post-drive images and DAN active observation. On Sol 1815, we have a short mid-day science block, during which ENV will conduct a suprahorizon movie and dust devil survey. ENV also has its standard REMS observations.
In a boat at sea one of the men began to bore a hole in the bottom of the boat. On being remonstrating with, he answered, "I am only boring under my own seat." "Yes," said his companions, "but when the sea rushes in we shall all be drowned with you."

BridgeTroll

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Re: Mars Rover Curiosity
« Reply #213 on: September 13, 2017, 08:41:00 AM »
In a boat at sea one of the men began to bore a hole in the bottom of the boat. On being remonstrating with, he answered, "I am only boring under my own seat." "Yes," said his companions, "but when the sea rushes in we shall all be drowned with you."

BridgeTroll

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Re: Mars Rover Curiosity
« Reply #214 on: September 20, 2017, 09:30:14 AM »
https://www.astrobio.net/news-exclusive/ancient-lake-mars-hospitable-enough-support-life/

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ANCIENT LAKE ON MARS WAS HOSPITABLE ENOUGH TO SUPPORT LIFE
By Amanda Doyle - Sep 18, 2017

An up-close view of Mars’ rocky deposits by NASA’s Curiosity rover shows a changing climate in the planet’s ancient past that would have left the surface warm and humid enough to support liquid water — and possibly life. Evidence of an ancient lake points to the prospect of two unique habitats within its shores; the lower part of the lake was devoid of oxygen compared to an oxygen-rich upper half.

In a recent paper published in the journal Science, “Redox stratification of an ancient lake in Gale crater,” Stony Brook University geoscientist Joel Hurowitz and his colleagues used more than three years of data retrieved from the rover to paint a picture of ancient conditions at Gale Crater, the lowest point in a thousand kilometers. The site, a 150-mile kilometer crater formed during an impact around 3.8 billion years ago, once flowed with rivers ending in a lake. The sedimentary rocks laid down by these rivers and onto the lakebed tell the story of how the environment changed over time.

Curiosity landed on a group of sedimentary rocks known as the Bradbury group. The rover sampled a part of this group called the Sheepbed mudstones, as well as rocks from the Murray formation at the base of the 5-kilometer high peak at the center of the crater known as Mount Sharp. Both types of rocks were deposited in the ancient lake, but the Sheepbed rocks are older and occur lower in the stratigraphic layers of rocks. Comparing the two types of rocks can lead to interesting revelations about the paleoenvironment.

Rocks that form at the same time in the same area can nevertheless display differences in composition and other characteristics. These different groupings are known as “facies” and the Murray formation is split into two facies. One is comprised mainly of hematite and phyllosilicate, and given the name HP, while the other is the magnetite-silicate facies, known as MS.

“The two Murray facies were probably laid down at about the same time within different parts of the lake,” explained Hurowitz. “The former laid down in shallow water, and the latter in deeper water.”

Curiosity landed on rocks known as the Bradbury group. The Murray formation consist of younger rocks at the base of Mount Sharp. The height is exaggerated in the diagram. Credit: NASA/JPL-Caltech

The near-shore HP facies have thicker layers in the rocks compared to the thin layers of the deeper water MS facies. This difference in layer thickness is because the river flowing into the lake would have slowed down and dumped some of its sedimentary material at the lake shore. The flow would then have spread into the lake and dropped finer material into the deeper parts of the lake. .

The different mineralogy of the two facies was caused by the lake becoming separated into two layers. Ultraviolet (UV) radiation along with low levels of atmospheric oxygen penetrated the upper part of the lake and acted as oxidants on molecules in the water. These ions of iron (Fe2+) and manganese (Mn2+) were brought to the lake via seepage of groundwater through the lake floor.

When the UV and oxygen interacted with these, they lost electrons, meaning that they had become “oxidized.” The oxidized iron and manganese precipitated into minerals — hematite and manganese oxide — that eventually made up the rocks sampled by Curiosity in the HP facies. However, the UV and oxygen didn’t reach all the way to the lake floor, so the iron and manganese wasn’t oxidized in the deeper part of the lake, and instead became the mineral known as magnetite, making up the MS facies.

The difference in oxidation of the two facies in the Murray formation due to differences in layers of the lake is known as redox stratification. Identifying redox stratification in the ancient lake shows that there were two completely different types of potential habitat available to any microbial life that might have been present.

The researchers also discovered that the Murray formation has a high concentration of salts, which provide clues relating to evaporation of the lake, and thus the end of the potential habitat. High salinity is a result of water evaporating and leaving salts behind. However, evaporation leaves other tell-tale signs such as desiccation cracks — similar to what you see when mud dries and cracks — and none of these signs appear in the Murray formation. This indicates that the evaporation occurred at a later period of time and that the salts seeped through layers overlying the Murray formation before becoming deposited in the Murray rocks.

“Curiosity will definitely be able to examine the rocks higher up in the stratigraphy to determine if lake evaporation influenced the rocks deposited in it,” said Hurowitz. “In fact, that’s exactly what the rover is doing as we speak at the area known as Vera Rubin Ridge.”

The inflowing river deposits thicker material (clastics) close to the lake shore, and finer material towards the deeper part of the lake. The incoming UV and O2 oxidizes the iron and manganese in the upper part of the lake, but not the lower part of the lake. This creates what is known as redox stratification and is reflected in the different mineralogy of the two different facies of the Murray formation. Credit: Hurowitz et al. (2017). Science.

Once Curiosity examines these rocks, it will be able to confirm that the salts found in the Murray formation came from a later period of evaporation, and therefore no significant evaporation occurred during the time that the Murray formation was deposited, meaning the environment would have been stable enough to support possible life forms.

Another result of the research is evidence of climate change. The older Sheepbed formation shows very little evidence of chemical weathering compared to the Murray formation. The change to substantial chemical weathering in the younger rocks indicates that the climate likely changed from cold, arid conditions to a warm, wet one.

“The timing of this climate shift is not something we can tell for sure because we haven’t seen the Sheepbed member and the Murray formation in contact with each other,” said Hurowitz. “If we had, then we might be able to tell if the change in their chemical and mineralogical properties were abrupt (indicating rapid climate change) or gradual. At best, what we can say is that the rocks that we examined were likely deposited over a timespan of tens of thousands of years to as much as around 10 million years.”

The cause of the climate change on Mars is still a matter of debate. If the climate changed in a short period of time, it could have been due to short-term variations or an asteroid impact. A slower change in climate could have been the result of changes in the obliquity cycle of the planet.

The climate change indicated in the rocks shows that the ancient Martian environment would have been warm and humid enough to sustain liquid water on the surface. The redox stratification of the lake as revealed by the different mineralogy in the Murray formation shows that there would have been two different environments within the lake itself. If microbial life was present on Mars at this time, the different potentially habitable niches could have encouraged diversity with anaerobic forms possibly living in the lower depths of the lake.

“I’m not sure that this was something we would have predicted if we hadn’t had the opportunity to examine Gale’s rock record up close and personal,” adds Hurowitz.
In a boat at sea one of the men began to bore a hole in the bottom of the boat. On being remonstrating with, he answered, "I am only boring under my own seat." "Yes," said his companions, "but when the sea rushes in we shall all be drowned with you."