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Curiosity exceeds expectations of its creators

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The 44th Lunar and Planetary Science Conference is taking place in the U.S., where the new results of Mars exploration conducted by the MSL Curiosity will be made public. Scientists from the U.S. said they were pleasantly surprised by the capabilities of their MastCam cameras, which were able to see things that were not expected, and scientists from Russia said they were surprised by the surface of Mars, which was saturated with water in a way that no models promised.
(Fair warning : lots of science and graphs inside).
Curiosity exceeds expectations of its creators
MastCams are two color two-megapixel cameras located on the mast of the rover. They have a fixed focal length: the right one is 100 mm and the left one 34 mm. This allows the right "eye" to be used for detail photography and the left eye for overview photography. When Curiosity was first designed, 3D movie fan James Cameron put a lot of effort into flying two identical cameras with variable focal lengths. They were made but didn’t make it through testing, so Curiosity is farsighted in one eye and near-sighted in the other. (A detailed technical description of these cameras and some other Curiosity devices can be found at : here )
However, this does not prevent you from creating high quality stereo panoramas. (Available on facebook at #MarsAnaglyph. ).
The cameras feature a 1600×1200 Kodak KAI-2020 CCD sensor with a standard Bayer filter , which means they shoot color photos without the processing that was needed its Martian predecessors. In addition to a fixed filter, each camera is equipped with a set of additional filters that allow only a certain wavelength to pass through. They are located on the wheel between the lens and the sensor.
Curiosity exceeds expectations of its creators
A combination of Bayer filters and optional filters, provides up to 12 different spectral ranges in which the Curiosity can survey. And only half of the filters capture the visible range, while the rest allow for analysis in the infrared range, which is inaccessible to the eye.
Curiosity exceeds expectations of its creators
All of this allows the surface to be explored in more detail than even the experienced eyes of a human geologist would provide. Scientists compared the MastCam imagery and compared it with spectral data obtained with other instruments. This allowed them to discover that multispectral imaging is able to identify hydrated materials, i.e., those in which water was involved and contained in their formation.
Curiosity exceeds expectations of its creators
The graph on the left shows the degree of light reflection of different wavelengths of the Knorr site as recorded by the mast cameras through different filters, while the right shows the degree of reflection characteristic of different materials. The dip in infrared light for hydrated materials is characteristic. The clay in which light veins are visible, although formed by the action of water, does not include it at the molecular level, so the difference is determined by MastCam photography.
NASA uses color coding that reflects a "hydration signal" of varying strength :
Curiosity exceeds expectations of its creators
The Tintina pebble that was broken off by the wheel showed a white kink :
Curiosity exceeds expectations of its creators
And his hydration signal turned out to be very strong :
Curiosity exceeds expectations of its creators
But a comparison of the four surface areas at the John Klein site of hydrated materials showed no difference, although the difference in ground characteristics is visible :
Curiosity exceeds expectations of its creators
At the conference, they also talked about the difference between raw, natural, and white balanced color images. No matter how one may want it, the real Mars is "redder" than even what is shown by the rover cameras. And the colors that are close to our vision are obtained by additional processing "as if we were seeing on Earth".
Curiosity exceeds expectations of its creators
NASA obtained this data by using color markers placed on Curiosity’s "sundial."
Curiosity exceeds expectations of its creators
In order to reveal finer color details, a false color treatment is done, and its falsity will show up if you look at the "sundial" in the same mode:
Curiosity exceeds expectations of its creators
Mars’ dull orange-brown color is due to its dustiness, while fresh fractures expose unexpected colors like this white-blue Sutton_Inlier stone.
Curiosity exceeds expectations of its creators
From news from California, let’s move on to news from Moscow.
At the same Lunar and Planetary Conference, Russian representatives shared the results of the DAN instrument.
Let me remind – this is a device, which registers with what energy neutrons fly out of the surface of Mars. It does this when it is bombarded by cosmic charged particles, or from a DAN neutron source. Depending on whether the device catches cosmic neutrons or produces them itself, its modes of operation are called passive or active.
Curiosity exceeds expectations of its creators
Hydrogen in the ground inhibits neutrons, so you can determine how much of it is under the instrument by estimating the percentage of "fast" and "retarded" particles. In the bulk, hydrogen means either water or hydroxyl (OH). The detector detects confidently to a depth of 60 cm, but is also capable of picking up signals up to 1 m.
Even when Curiosity crossed the first hundred meters, scientists noted that the data from DAN were generally as expected: the ground was very dry and only at the maximum achievable depth did water reach 5%, and above it did not exceed 1%. This was quite predictable, because on the Martian equator during the summertime temperatures can rise above 30 degrees Celsius, and low pressure causes the water to evaporate immediately. Such conditions leave no chance of finding ice within half a meter to a meter of the surface.
As Curiosity descended into Yellowknifle Bay, which is thought to be the bottom of an ancient lake, the data from the instrument began to surprise. It began to show that, in places, the top layer of the surface is wet – up to 3%, and under it begins "desert" with 1% of water content. That is, DAN revealed the "layering" of Mars even at shallow depths, and this data will allow scientists to present a fuller picture of the changes on the planet that led to the situation that is observed now.
Curiosity exceeds expectations of its creators
The difference in readings was determined not only on significant portions of the mileage :
Curiosity exceeds expectations of its creators
But also in the few "steps" of the Mars rover :
Curiosity exceeds expectations of its creators
Scientists are still in no hurry to interpret the information and will continue to work further. Although the rover is not expected to move in the coming weeks, so we will not see updates from DAN anytime soon. We can only hope there will be a rematch when Curiosity sets off on its long journey to Mt.
At the conference, the Canadians also shared their results.
They are working with the Alpha Proton X-Ray Spectrometer (APXS) instrument, which is located on a manipulator :
Curiosity exceeds expectations of its creators
It allows you to determine the chemical content of the surface to be examined. In order to improve the quality of analysis, Curiosity is equipped with a brush that removes dust :
Curiosity exceeds expectations of its creators
APXS did a lot of analyses, but we published the results of one, from the Portage site. The graph shows, in schematic form, the content of different elements in three types of surface: untreated, cleaned, cleaned, and rich in white veins. The latter is distinguished by a high content of sulfur and calcium, which generally corresponds to gypsum.
Curiosity exceeds expectations of its creators
The conference is still going on, and the results will be updated in the next couple of days. At least material on the ChemCam laser is expected.
Over the weekend, the Curiosity computer again produced an error, but this time the problem was quickly identified and corrected – the culprit was a faulty file that was deleted. The rover should be back to work in the next few days, but on April 4 it will be out of contact for 4 weeks while the Sun passes between Mars and Earth. I think at this time I will finish what was said at today’s conference.

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