MARS CORRECT BASIC REPORT - SECTIONS 14.6.3 TO 14.7
Range and sensitivity of pressure sensors sent to Mars. This section updated on 10/20/2017.
14.6.3 Mixed messages about the range and sensitivity of pressure sensors sent to Mars.
It has on been our position that NASA has understated Martian pressure by two orders of magnitude. On Figure 46 we made a case for a pressure at areoid of about 511 mbar (vs. the accepted pressure of 6.1mbar), at Mars Pathfinder of ~719 mbar, at MSL ~768 mbar, at the Valles Marineris 835 mbar and in the Hellas Basis about 1,054 mbar (more than average pressure of 1,013.25 mbar at sea level on Earth). While mbar are the pressure units that we most prefer, others in the scientific community use pascals (Pa) or hectopascals (hPa). We have often noted mistakes in publication where hPa are confused with Pa and vice versa. The difference between these units is two orders of magnitude (i.e., two decimal places).
The problem first came to our attention when we found that the REMS Team originally published pressures ranging from 737 to 747 hPa between August 30, 2012 and September 5, 2017. On September 2, 2012 we called Guy Webster, the PR man at JPL, and told him that if these pressures were correct, he needed to parade out the President of the United States to announce the greatest discovery in astronomy – that Mars has air pressure like than on Earth. On September 5, 2012 REMS said the pressure was 747 hPa (i.e., 747 mbar). The next day they published a pressure of 747 Pa (i.e. 7.47 mbar). This was captured by print-screen on Figure 17A. Soon after that they changed all the high pressures, rolling them back from hPa to Pa. Was this a simple accident?
We have worked for eight years with Viking 1 and 2 data taken from "Mars Meteorology Data; Viking Lander." Mars Meteorology Data; Viking Lander. N.p., n.d. Web. 10 Feb. 2015. This is found at http://www-k12.atmos.washington.edu/k12/resources/mars_data-information/data.html. On July 12, 2017 we received an e-mail from an engineer by the name of Nathan Mariels, CEO at Global Electric Technology. In it he wrote:
Pa is not equal to hPa. From Viking logs: "Pressure mb = millibars, 1 mb = 100 hPa, where hPa = hecta Pascals" This is incorrect. 1 mb = 1 hPa = 100 Pa.
The above error was repeated on every data set for Viking 1 and 2. A sample is captured by print-screen on Figure 68.
Nathan found similar errors on MSL data that he examined. He also found different pressure ranges for landers than what we found, although we noted on Figures 10A and 10B that three of four sensor ordered by NASA from Tavis were rated for maximum pressures under 25 mbar, one of them – Tavis Dash Number 1 was rated at 15 PSIA which converts to 1,034 mbar. Pathfinder pressure problems were discussed earlier in Section 11 of this report. The Vikings and Pathfinder all used Tavis pressure transducers which are discussed in great detail in Annex G of this report (http://marscorrect.com/ANNEX%20G%2010%20September%202013.pdf). While it seems hard to believe that a mere copying over of wrong units from one page to another caused serious problems, that’s what might have happened with all of the Viking 1 and 2 data at http://www-k12.atmos.washington.edu/k12/resources/mars_data-information/data.html.
The problem with accepting the accident explanation for the Vikings is that it still leaves us with an order in 1976 by Dr. James Fletcher to manually alter the color of the Martian sky on all JPL monitors, and it leaves us with 36 years of altered sky color until we were finally permitted to see blue sky at Gale Crater, Mars in 2012.
Figure 68 above – Viking 1 and Viking 2 error in unit conversion.
Figure 69 above – The REMS Team would not permit low temperatures warmer than -50°C.
Now, let’s look at another problem brought to my attention by Nathan – an inconsistency with respect to the pressure range and sensitivity on MSL. In particular, let’s look at the Abstract put out by the Finnish Meteorological Institute, which created the pressure sensors on Phoenix and MSL.
First let's look at a statement that backs the 1150 Pa figure: In Section 11 of the REMS Calibration Plan (Document No, CAB-REMS-PLN-002, Issue 002, it states:
REMS shall measure the Ambient Pressure in the range of 1 to 1150 Pa with a resolution of 0.5 Pa and accuracy of 10 Pa BOL and 20 Pa EOL. Requirement 012 (PLD-20), REMS shall measure the Ambient Pressure at a minimum sampling rate of 1 Hz for at least 5 minutes each hour continuously over the mission.
The pressure device measurement range is 0 - 1025 hPa in temperature range of -45°C - 55°C, but its calibration is optimized for the Martian pressure range of 4 - 12 hPa.
Note: 1025 hPa = 1,025 mbar. So, while it was supposedly optimized for 4 to 12 (not 11.5 mbar – meaning that the problem is not one of a sliding decimal place), it was still capable of measuring up to 1,025 mbar. Again, average pressure on Earth at sea level is 1,013.25 mbar. This is, to borrow a phrase from the Wizard of Oz, a horse of a different color. As for the temperature range, at MSL there were no reports of low temperatures as warm as -45°C that were not changed to much colder temperatures. For example, there was an air temperature low of -46°C reported by the REMS Team for Sol 880 on January 27, 2014, but they altered it after we highlighted it on our REMS data spreadsheets at http://marscorrect.com/photo4_11.html and in particular the print-screen record seen below as Figure 69.
For the record, we have preserved the FMI abstract showing the 1,025 mbar capacity with the print-screen on Figure 70.
Figure 70 – Print-screen (recorded on July 23, 2017) of the FMI Abstract entitled Pressure and Humidity Measurements at the MSL Landing Site Supported by Modeling of the Atmospheric Conditions.
In contrast to what they submitted to the American Geophysical Union in 2012, the standard REMS position on the range of their MSL pressure sensor is shown on Figure 71.
Figure 71 - The Vaisala Pressure sensor and its range as depicted by Spaceflight101.com.
On July 24, 2017 we found that the REMS Team again altered the maximum pressure to 1400 Pa (14 mbar). See Figure 72. After they raised the maximum pressure from 1150 to 1400 Pa, they published a maximum pressure of 1,294 Pa for Sol 1784 on August 13, 2017. On the previous sol (1783) the presure published was only 879 Pa. Yet even with the newer (likely false) upper pressure range of 1,400 Pa, when we challenged it with our colored spreadsheet and print-screen (http://davidaroffman.com/photo5_15.html), the REMS Team dropped the 1,294 Pa for that sol to 883 Pa.
Figure 72 – REMS puts out a new maximum pressure for MSL. This time it’s 1400 Pa (14 mbar). Here they also claim a relative accuracy (repeatability in the time scale of hours) of less than 2 PA and a resolution of 0.2 Pa. On Figure 69 the resolution was 0.5 Pa.
14.6.4. A Possible Excuse for REMS Errors.
Nathan Mariels examined the Planetary Data a System (PDS) for MSL data. On July 18, 2017 at 8:07 PM, he wrote:
“There are a lot of data points. Every 5 minutes, unless an event occurs, which causes it to sample 512 points at short intervals. The triggers and timing change depending on the code version. REMS is on version 7. I think that's why you see the pressure from past dates sometimes change. The format of the data changes, so the weather software gets changed, but some older data is then getting converted wrong if the software thinks it's all in the new format.”
14.7 Temperature, Pressure and Albedo.
This section merges our findings with an article written in Italian by Marco de Marco (http://www.pianetamarte.net/gale_crater.htm).
Marco states that, “Gale crater is located south of the Martian equator. According to NASA's albedo maps, the average value recorded is 0.193, with a minimum of 0.111 and a maximum of 0.278; the place for landing has an average albedo of 0.171. With these values it’s possible to calculate the maximum daily temperature, taking into account the inclination of the sun rays in relation to the Martian season. From it, distance of Mars from the sun and albedo it’s possible to obtain the temperature using Boltzmann’s Law which states that the total energy radiated per unit surface area of a black-body radiant emittance or radiant exitance is directly proportional to the 4th power of the black body's remperature.
“By applying this principle to the conditions of the Gale crater, we already have the first surprises, especially if compared to the data provided by Thermal Emission Spectrometer (TES) from Mars Global Surveyor. In the comparison graph between the calculated data and the values provided by TES for latitude 0 ° and -10 °, there is some discrepancy between the temperatures of those latitudes and theoretical values which could only be explained by accepting values of albedo much higher than the actual ones. From the complete analysis of TES temperature data it can be seen that Mars should have an average albedo of 0.44, where visual albedo is 0.15 and geometric albedo is about 0.3. Always according to TES data the albedo itself varies according to the temperature. This behavior is quite curious! In fact, the albedo map supplied by NASA varies from a minimum of 0.08 to a maximum of 0.32, while according to TES data albedo ranges up to a maximum of 0.84 for polar regions and up to 0.56 in equatorial regions.
Figure 73 - Maximum temperature calculated according to Boltzman’s Law with TES measurements from the equator to -10° latitude (10° South latitude)
“The only explanation for this phenomenon, obviously taking the TES data as correct, would be the massive presence of cloud formations, especially in colder times, as opposed to the activities related to sand storms that usually occur in the warmer moments which in itself would exclude the sand storms from the explanation of this phenomenon. However, since this fact is unconfirmed, it would be more appropriate to deduce the presence of a variable error percentage in the TES data, particularly at the lower temperatures, as shown in Figure 73 above.
“Returning to the TES data, we will expect temperature variations from a minimum of -16 ° C to a maximum of + 31 ° C. Instead, according to my calculated data, taking into account the different degrees of albedo I would expect variations from a minimum of -2 ° C up to a maximum of almost +49 ° C, as far as the whole crater is concerned. With respect to the specific landing area, the values would vary from a minimum of + 8 ° C to a maximum of + 43 ° C, practically always above the freezing point of the water, at least as far as the maximum daily temperature. As you may also notice the temperature should easily exceed even + 40 ° C.
“Curiosity landed inside Gale crater, on August 6, 2012, when Mars was at the solar longitude (Ls) 150.4 just before spring equinox the southern hemisphere. According to the graph, at that time the temperature should reach a maximum of + 26 ° C with upward trend. Let's remember then that any phenomena related to the presence of liquid water will provide us with great information on the actual Martian atmospheric density. In fact, Gale crater also has a certain amount of water, with a percentage of between 6 and 8% of the ground mass, also proved by the presence of gullies! It would be extremely interesting to be able to watch live from the Curiosity cameras this water spill from the ground at recurring slope lineae (RSL), as well as the same water behavior once on the surface. If the soil temperature exceeds + 40 ° C, then we will have to shift the lower limit for the Martian atmospheric density to no less than 80 hPa.” However as is demonstrated throughout the Mars Correct Basic Report there appears to be major flaws in temperature data, one of which is that the REMS Team let us know that ground temperatures are only accurate to +/- 10 °C. In looking through the first 1,841 sols at MSL, the highest ground temperature reported by the REMS Team was +24 C ° on Sol 1,428.
Figure 74 - Combining day and night infrared shooting, I have obtained this map in false colors where red spots area areas that tend to warm up more quickly during the day, while green resembles areas that tend to retain more warmth overnight, everything else is shown in blue.
Marco continues, “Another proof of the presence of water inside the Gale crater is provided by the infrared thermal images taken in day and night. Analysis of them provides us with very valuable information on the physical nature of the soil. What appears brighter in a photo, during the day, is given by everything that is able to quickly absorb solar thermal energy by rapidly changing its temperature. Conversely, what remains brighter in a nighttime thermal photo is given by everything that tends to accumulate heat energy, dispersing it and absorbing it much more slowly than anything else. This process, otherwise termed thermal inertia, is also an indicator of the density of a body. In fact, a low-density object tends to warm (or cool) much faster than an object with a higher density, which vice versa will react much more slowly to temperature changes.
“Comparing the two infrared, day and night shootings, we can build a map of the distribution of the thermal inertia of the Gale crater. In the map shown, the red corresponds to the hottest areas during the day and therefore to low thermal inertia, the green is the hottest areas at night and therefore high thermal inertia, all the rest is represented in blue. By comparing this type of analysis with other areas of Mars, it is easy to conclude that in many cases green indicates water deposits, as it coincides with the Gullies spillages and the underlying collection areas. It cannot be considered as a certainty of the presence of water, as other materials may mimic the same behavior, but it is also true that all areas where water spills are observed as well as the collection areas are always green in this type of analysis.