hint: we’ve been to Mars before…
At sea level, Earth has an atmospheric pressure of 14.7 PSI (pounds per square inch).
Before the Viking spacecraft landed on Mars in 1976, it was thought that the atmospheric pressure of Mars was somewhere between 0.4 PSI and 4.4 PSI. When the Viking spacecraft landed, the pressure sensor appeared to indicate that the atmospheric pressure on the surface of Mars was 0.09 PSI.
What I propose is that there was a math error, specifically a units error in the conversion of pressure sensor data, where Pa and hPa were not considered as different units. The difference is a factor of 100.
If true, Mars has an atmospheric pressure of 9 PSI. This has rather large implications for our understanding of physics, and may be an explanation why most spacecraft attempting to land on Mars fail, and the ones that do land are many miles from the intended landing location.
The question I asked myself a few years ago, and still can not answer is:
The sky is not black when viewed from Mars rovers.
At 100,000 feet on Earth, the pressure is similar to the currently accepted pressure on Mars, and the sky is black.
If the diffuse light on Mars is from the dust, what is holding up the dust? (Most likely not turtles.)
Why does it matter if the pressure is 60% of Earth's?
We could use aircraft on Mars.
We could roam the planet of Mars without spacesuits using just warm clothing and rebreathers.
The mathematical equations of physics fit together in a nice way that currently can not be done.
The question above about where the diffuse light comes from has an answer: An atmospheric pressure of 9 PSI would cause diffuse light and could hold up the dust.
Evidence for the units error (Pa vs. hPa):
From Viking logs (First successful US lander on Mars, July 20, 1976 - Units error in conversion of pressure data - off by a factor of 100)
"C Pressure mb = millibars, 1 mb = 100 hPa, where
C hPa = hecta Pascals"
-Viking Lander 1 Binned and Splined data Rev 2.2 97/6/19, JET, lines 50-51
The conversion factor above is incorrect.
The correct conversion factor is: 1 mb = 100 Pa
(mb: millibars, hPa: hectopascals, Pa: pascals)
Mars Science Laboratory (Currently operational US rover on Mars - Discrepancies in pressure units - Pa vs. hPa - off by a factor of 100)
REMS Instrument Pressure Sensor (Vaisala Barocap):
"Pressure in the range of 1 to 1150 Pa with a resolution of 0.5 Pa"
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NASA website
"Pressure range 50 … 1100 hPa"
"Resolution 0.5 hPa"
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Vaisala Datasheet for PTB200 Barocap
REMS testing of Barocap: Capacitance varies from 14 to 12 pF over the range of 0-1000 Pa
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REMS Space Science Reviews 2012 DOI 10.1007/s11214-012-9921-1, figure 12
My testing of Barocap: Capacitance varies from 14 to 12 pF over the range of 0-1000 hPa
Sample REMS pressure data close in time to SAM data below:
Log file: RME_399133183ESE00190000000ACQ____M1.TAB
REMS Barocap : 399177611.0 SECONDS, 721.15 Pa
SAM Instrument:
CDH:PRES_4_MN6: 399118971.8 SECONDS, 711.5 MILLIBARS
Unit #4, A-DIR, Direct atmospheric measurement, ADIR
Log file: sm25008f0018rdr1a_adir_hk__cdhlspd_2.csv
Additional data that supports the idea that Mars has an atmospheric pressure of 9 PSI (60% of Earths):
ESA Lander Failure (Mars atmosphere not as expected)
Root Cause of failure: "Insufficient uncertainty and configuration management in the modeling of the parachute dynamics"
-EXOMARS 2016 - Schiaparelli Anomaly Inquiry
MSL Heat shield (Mars atmosphere not as expected):
"The peak temperature at MISP 7 is ~210 deg C greater than model predictions."
-MSL Entry, Descent and Landing Instrumentation (MEDLI): Hardware Performance and Data Reconstruction - AAS 13-078
Analysis of Strategic Knowledge Gaps Associated with Potential Human Missions to the Martian System
"FINDING #1. The high-priority gaps for a human mission to Mars orbit relate to
a) atmospheric data and models …"
-NASA, P-SAG_final_report_06-30-12_main_v26.pdf
Before the landers (The 30 mbar vs. 300 mbar problem)
"The principal difficulty affecting all of the photometric and polarimetric investigations is that of distinguishing between the amount of light scattered by the Martian surface, by the solid particles in the atmosphere and the atmosphere itself. The surface pressure can be computed also from the pressure broadening of the lines in the Martian band spectrum of CO2. The first results of the spectroscopic method disagree by an order of magnitude from previously accepted values, which were based on photometry and polarimetry. Other spectroscopic measurements made by numerous investigators in 1964 and 1965 confirmed this disagreement mentioned above."
-Karl D Rakos, The Atmospheric Pressure at the Surface of Mars, Lowell Observatory Bulletin No. 131, 1965