Earth's Moon, Apollo Mission
Low Atmospheric Pressure
Harsh Shadows


Earth's Moon, Chang'e-3 Lander
Low Atmospheric Pressure
Harsh Shadows


Mars, Insight Lander
??? Atmospheric Pressure
Soft Shadows


Mars, MSL Rover
??? Atmospheric Pressure
Soft Shadows


14.7 PSI Atmospheric Pressure
Soft Shadows


14.7 PSI Atmospheric Pressure
Soft Shadows

This page is about a possible error in the standard view of physics that relates to the pressure on the surface of Mars.

At sea level, Earth has an atmospheric pressure of 14.7 PSI (pounds per square inch).

This atmosphere allows life as we know it to exist on our planet. Without the atmosphere there would be no liquid water on the surface of our planet and plants would not grow. If you went outside, your blood would boil and there would be no air to breathe.

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.

Units errors have caused the loss of several spacecraft, including one to Mars.

"root cause for the loss of the MCO spacecraft was the failure to use metric units in the coding of a ground software file"
- Mars Climate Orbiter Mishap Investigation Board Phase I Report November 10, 1999

The question I asked myself a few years ago (and, individually, 475 other people since then), 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.)

What are units?

Temperature can be expressed in several ways. For example, 68 degrees Fahrenheit is the same as 20 degrees Celsius, and is considered comfortable by most people. 68 degrees Celsius is 154.4 degrees Fahrenheit will kill most living things very quickly. "Celsius" and "Fahrenheit" are units of temperature. Units are what relate a number to what the number represents.

Pressure can also be stated in several different units. In the US, Pounds Per Square Inch (PSI) is common, while Pascals (Pa) are common elsewhere.

The following are all equivalent ways of stating the pressure of the Earth's atmosphere at sea level: 14.7 PSI, 101325 Pa, 1013 hPa, 101.3 kPa, 760 mm hg, 760 mm, 1.013 bar, 1013 mbar, 1 ATM, 29.9" hg, 0 PSIG, 14.7 PSIA

Note 1: "Pa" and "hPa" are a factor of 100 different, while "mm hg" and "mm" are equivalent.

Note 2: Common pressure gages for tires and air compressors read the pressure relative to the atmospheric pressure (PSIG). When your car tire gauge reads 30 PSI, the tire has 44.7 PSI on the inside, 14.7 PSI on the outside, with a difference of 30 PSI between the inside and outside pressure. (At sea level)

Why does it matter if the pressure on the surface of Mars is 60% of the pressure on the surface of Earth?

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"

- NASA website

"Pressure range       50 ... 1100 hPa"

"Resolution                           0.5 hPa"

- Vaisala Datasheet for PTB200 Barocap

REMS testing of Barocap: Capacitance varies from 14 to 12 pF over the range of 0-1000 Pa

- 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

- Nathan Mariels

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

Arguments against the above:

1) The modifications to the Barocap for Mars may be different than what is documented. (Details are sparse.)

2) The WRP turbo pumps on MSL would not work if venting to 700 hPa. (Are they working? Is the Mass-Spec working without the pumps? Anyone have expected current draw and spin-up times? Are 77 seconds to 8K RPM, 14 more seconds to 40K RPM, and 43 more seconds to 100K RPM expected times? Could the second WRP be run backwards as a backing pump to get things working on MSL)

3) Spacecraft would have burned up if the atmospheric pressure was 60% of Earth's. (Most of the landers/rovers that did successfully land used rockets and radar altimeters to do so, and were not dependent on the atmospheric pressure data. All of the landers/rovers landed downrange from where they expected, possibly from drifting in the atmosphere before the parachutes were cut free. See notes above on MSL heat shield temps and ESA lander failure above.)

4) It goes against the standard scientific model of our solar system that so many people agree on. (For everything except the Martian atmospheric pressure, and what depends on it, I agree with the standard accepted view of the scientific community.)

This section is an idea that needs to be evaluated by others before being considered correct.

If we assume that the currently accepted values for atmospheric pressures of Mars and Venus are off by a factor of 100 and 0.01 respectively, the following equations work rather well:

Proposed Eq 1: maximum equilibrium surface pressure (Pa) = 32300 * square root of gravity (m/s^2)

Proposed Eq 2: maximum equilibrium surface pressure (PSI) = 4.69 * square root of gravity (m/s^2)

Proposed Eq 3: P1/P2 = sqrt (g1/g2), where P is the maximum equilibrium surface pressure a planet can support and g is the gravity of the planet in m/s^2

Three examples that show very good correlation for Proposed Eq 3:

Mars/Earth: 9.0/14.7 = 0.612, sqrt (3.7/9.8) = 0.614

Venus/Earth 14.0/14.7 = 0.952, sqrt (8.9/9.8) = 0.953

Mars/Venus 9.0/14.0 = 0.643, sqrt (3.7/8.9) = 0.645

Some estimated planetary surface pressures (in PSI): Mercury = 9.0,     Venus = 14.0 (not 1400),     Earth 14.7     Mars = 9.0 (not 0.09)     Uranus = 13.9     Neptune = 15.6

Some values of planetary gravity (in m/s^2):                Mercury = 3.7      Venus = 8.9                         Earth 9.8,      Mars = 3.7                     Uranus = 8.7,      Neptune = 11

An atmosphere is not a closed system. One side is the rocks, dirt and water, the other is diffusion into space. The square root term comes from the atmospheric weight not being constant with gravity. If gravity increases, it may cause more condensation and absorption, leading to a decrease in atmospheric weight, partially counteracting the pressure increase.

Note: These equations imply that our Moon could support an atmospheric pressure of up to 5.9 PSI.

Mars and Phobos
Mars and Moon (Phobos) taken by Mars Orbiter Mission
                Barocap Testing
Barocap Testing showing Pa vs. hPa discrepancy (factor of 100)

Mars Drilling

First two images: "Laboratory drilling under Martian conditions yields unexpected results",
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 109, E07S10, doi:10.1029/2003JE002204, 2004
Third image: Mars Rover, MSL, CR0_580106913PRC_F0701752CCAM05056L1

(This is the least compelling evidence, but still suggests the pressure is closer to 9 PSI that 0.09 PSI on the surface of Mars.

Below this line are concepts based on "exterminate all rational thought."

Black holes are simply holes in perception.

Stars look very different at 60 fps compared to multi second exposures commonly done. They are no longer just points of light.

Physics is a set of polynomial approximations, that each work well in their limited scope, to give similar numerical results as the actual equations we do not yet know.

At what rate does the cadmium of newer solar cells sublime and re-condense on to optics of satellites?

On the F-35, what electrical system components are shared by the pilots oxygen system and navigation lights?

If you use a PRBS 2^7-1 as the clock for an 8 bit counter, does the high bit have a 50% duty cycle?

I had been sailing more than a hundred times at sunset before I saw the green flash (High Roler, 77090). You will know you have seen it when you have; just like to first understands recursion, you must first understand recursion.

Many weather balloons using radiosondes no longer report actual pressure data, but instead report estimated pressure based on GPS position, temperature and humidity. (Vaisala Radiosonde RS41 is one example.)

"Johnny had three truckloads of plutonium. He used three of them to power New York for a year. How much Plutonium did Johnny have left? Four truckloads." -U.S. D.O.E.

The usable energy content of one cubic foot of uranium is approximately the same as contained in 100,000,000 gallons of gasoline, and makes one cubic foot of waste.

In the 2011 magnitude 9.0 earthquake near Japan, and the resulting tsunami, 14308 people drowned, 667 were crushed to death, 145 died from burns, 6156 people were injured by various means, and one person was hurt by falling glass in the meltdown of a nuclear reactor.

When does SHA256 (ivec,block) = ivec?
ivec: 2EC557A2 0B6E2499 0CF13E72 2CDD2309 CD4AB124 B54D3298 9FBAAA26 595767F4
block: 4E617468 616E4D61 7269656C 73800000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000068
hash: 2EC557A2 0B6E2499 0CF13E72 2CDD2309 CD4AB124 B54D3298 9FBAAA26 595767F4

Note that SHA256 (ivec,block) = SHA256 (ivec,block,block) for example above.         sha256mt.c, sha256inv.cpp, sha256fixedpoints.c, sha256collisions.c

Let's build nuclear powered rocket engines, similar to NERVA, for manned missions to Mars and beyond.

Comments are appreciated. If you have additional supporting information, or if you think that any data, or even the entire concept, is wrong, please let me know. -Nathan     Phone: (354196 times 14407)

This website is because I had thought the atmospheric pressure on the surface of Mars was 10 PSI before I found the units error. I now think it is likely 9 PSI.

I do not believe in the flat Earth. See turtle joke above.

My very own approximation in a Xilinx 9572XL