The Spirit and
Abstract:
Mars has many enigmatic features, such as Tharsis,
Olympus Mons, Valles Marineris, and Alba Patera. The volcanoes and Valles
Marineris are huge compared to the size of Mars with no apparent explanation
for what made them. In the theory outlined here the poles of Mars wandered
through history in response to 4 major impacts, Utopia, Isidis, Argyre, and
Keywords: astrobiology, crinoid, Gusev, Mars,
Meridiani,,
This theory originally came about from reading a paper
by Sprenke and Baker[1]
on a proposed polar wander path on Mars. In the process of examining this we
accumulated published papers referring to features along this path, and looked
at whether features there were consistent with having been on a pole.
Typically such
features would be formed by water or ice, and the terrain would be similar to
known geology we see on the current poles. This was contrasted with areas off
this polar path, which typically were much drier and ice free. Because the
proposed polar path went back to before Tharsis, Olympus Mons and Valles
Marineris it became possible this path was directed by the same forces that made
these formations, and much of the current Martian landscape. We found that
virtually every single paper published on Martian geology is consistent with
this polar wander path.
Because these large volcanoes have so much mass they
tend to move to the Equator, and so these could only form at certain times in
the polar wander. The polar path if correct then implies when these
Because of space limitations and the serendipitous
landing of the Rovers on two former poles opposite each other, we have
reproduced here the middle part of the polar path. In the next paper we will
show the possible events before this section that formed Tharsis Montes,
Olympus Mons, Elysium Mons, and Valles Marineris. A following paper will carry
on after this one, with the
While it is not known if life exists on Mars the polar
path strongly implies a habitable zone existed around these poles as they
wandered across Mars, for hundreds of millions of years or more. The large
volcanoes of Tharsis, Elysium Mons, and Elysium Mons may have heated the
planet, as they are associated with parts of the polar path that appeared to generate
huge amounts of water.
In the three papers we will refer to 5 pole positions
as being stable for a time, and the polar movement between these positions. The
current pole positions we call Pole 5, and the polar movement from Pole 2 to
Pole 3 is discussed here, Pole 4 is near Hellas Crater. To follow this path a
good map of Mars is essential as many of the names are obscure. If you Google
and download “mola_regional.pdf”[2]
this map shows all the place names referred to here. For any image numbers, placing
the image number in a search engine and selecting the link from msss.com is the
fastest way to find them.
In this paper we concentrate on the movement from what
we call the South Polar Cap 2 position near Solis Planum (south of Valles
Marineris) to South Polar Cap 3 position at Meridiani Planum, shown in Figure 1.
The associated North Pole moved from the North Polar Cap 2 position around
Isidis Planitia eastward to near Lucus Planum as the corresponding North Polar
Cap 3. We call this North Polar Cap 3 because eventually it will go to the
current North Pole position. In this theory the Argyre impact starts the polar
wander from the second to the third position.
The path begins when the Pole is moving eastwards from
the South Polar Cap 2 position around Solis Planum, to north of Argyre Basin
into Margaritifer Terra and then east to Meridiani Planum, the site of South
Polar Cap 3. One should remember that a pole is very large in its influence, so
the exact position of the centre is often not significant. For example the
current poles are quite asymmetric in shape compared to the rotational pole
itself.
There is no direct evidence
for the Polar Cap stabilizing
or remaining in
Margaritifer Sinus for any great length in time along this route. Figure 1 shows this path, South Polar
Cap 2 to 3 is from Solis Planum to Meridiani Planum.

Figure 1: The proposed polar wander path from
Pole 2 to 3.
The large river networks in
the Xanthe Terra and Margaritifer Sinus areas imply the atmosphere at the time
was much thicker, since water would need a much higher air pressure than found
today. A higher polar obliquity may have
also contributed to this. The axial tilt of Mars is believed to change
periodically over time, and when the angle is greater the ice around the poles
is thought to melt or sublimate much more.
This gives a possible
habitable environment at this time, with abundant water, heat from the Argyre
impact, and higher air pressure. These water signs persist all the way along
the polar path to Meridiani Planum.
According to Grant[3]
Margaritifer Sinus contains remnant high valley densities, which is consistent with a moving pole and ice melting. This area was resurfaced several times[4],
perhaps from the subsequent volcanism related to the Argyre impact. Therefore, ice
may have partially vaporized, sublimed or melted, either due to impacts, and/or
due to subsurface heat from associated geothermal activity. While Grant[5]
believes some precipitation occurred, most ground water would be consistent with a water table associated
with either a forming or
sublimation/melting of an existing pole. The Parana Valles[6]
drainage system is particularly extensive. Therefore, according to Grant[7], groundwater discharge[8]
must have continued for some considerable time. The length
of time referred to would likely be sufficient for life, if present to evolve
substantially.
Lewis and Aharonson[9]
examine Holden Crater and the distributary fan discovered in it. This area is near
Argyre Crater and implies liquid water was discharged from the Polar Cap nearby.
Pondrelli et al[10] also
examine the area and how it connects the
Hynek et al[12]
suggest that the
fluvial resurfacing in this area lasted for a period of some several hundred million years. A
combination of rainfall and sapping[13]
appear likely, so lakes may well
have formed[14]. Polar wander may link the two main theories of
precipitation and sapping, hence explaining the extensive valley networks[15].
According to Nelson ice may have periodically melted. An
examination of Margaritifer
Sinus, by Philips et al[16]
concluded that much of the
Tharsis bulge was already in place before the drainage channels formed. This is consistent with the general rise
in elevation in the area of Tharsis and Sinai Planum from the Argyre impact. At
this time Tharsis and Olympus Mons would have been growing after the Argyre
impact, and their extra weight would tend to move to the Equator. This would
have the effect of forcing South polar Cap 3 to move eastwards to Meridiani
Planum. This part of the polar path (and its antipodes, the future North Pole)
shows abundant evidence of water and ice. The area around Margaritifer Sinus
was plausibly a habitable zone and the Rover Opportunity has now shown
Meridiani Planum was a habitable zone. In between these two there are enough
water signs to imply this was a long period of Martian history in which a
habitable zone existed. It is not known however if there was life there to take
advantage of this.
During the late Noachian, Tharsis Rise was large enough to direct the
channels northward. Large amounts of material eroded from this area were transported along these channels, most probably as a direct
result of basal water
erosion during melting (and sublimation) as the Pole moved north east
of Valles Marineris[17]
[18]
towards Margaritifer Sinus.
By the time the Polar Cap had moved north east of Valles Marineris
water and ice would
have accumulated in it as the Polar Cap melted and moved from the
Argyre impact event,
which may explain the paleolakes[19]
there. Carr[20]
suggested that ground water flowed into Valles Marineris and then into Chryse
Planitia, forming lakes. Rossi et al[21]
believe there is good evidence of ice and glaciation, consistent with a polar area adjacent
to and south of the Valles Marineris at that time. Glacial features in the area support this
interpretation.
Lunae Planum would also have received water from the
moving and melting of the pole. Shalbatana Valles originates in the chaos on
Lunae Planum (Greeley and
Kuzmin[22]). Interestingly this would
have resulted from a
probable impact basin that formed a catastrophic outflow.
Nelson and Greeley[23]
discuss three major
fluvial events in Xanthe Terra, with indications of surface water flow. The first is a broad
sheetwash from the Valles Marineris area, perhaps coinciding with the Argyre
impact. Following this
more extensive flooding occurred, forming Shalbatana,
As we follow the polar wander,
the fluvial-features seem to overprint other terrain, so flooding may have
continued as the Polar Cap migrated.
At the antipodes North Polar
Cap 2 near the growing Elysium Mons started to move eastward. This area has
many signs of ice and water, for example M0901921, M0905888, M0906366,
M1001498, M1900226, M1902068, M2000840, and M2000907. Again these photos from
the MOC can be seen by placing the image numbers in a search engine and
selecting the link from msss.com. Further signs can be seen in Martei Valles in
M2001192, M2200885, and SP238804. Lanagan et al[25]
see evidence of fluvial flows associated with Elysium Mons and lava flows in
the area, and rootless cones[26]
also indicate ice in the area.
The new Odyssey results of subsurface
ice[27]
indicate a large
deposit on the equator in Babaea Terra. A second area of ice occurs on the left edge of the map, just below the equator. This
corresponds to the location of
the opposite North Polar
Cap 3. According to
Sprenke et al the South Polar Cap moved in a curve to 0S 330W, almost into the centre of the ice rich area at
Meridiani Planum. We call this area South Polar Cap 3. The geology and the
geophysical data indicate icy areas on opposite sides of the planet. When we calculate the radius of
the planet and adjust for any faulting, the result suggests that these areas were almost
certainly a polar pair. For each Polar Cap pair we back-calculated the polar separations. The
differences in diameters are almost perfectly offset by the thickness of
rift-like valleys and fault movement and by assuming earth-like passive fault
movement the polar age relationships could be back calculated.
We believe the poles
stabilised in these ice rich areas for a long time, also with ample evidence of
water signs. Thus the possible habitable zone extends to the results we see
from the Rovers and implies similar chemistry and water signs may be found
along this whole polar path from Solis Planum.
Rift-like faults, glaciation,
evidence of surface water, and even volcanic activity tend to track the polar
movement. The movement
of Pole 2 to Pole 3 adds to approximately 150 degrees of longitudinal movement
so this is consistent with Tharsis forming near South Polar Cap 2 and then
moving nearly 180 degrees to the Equator, which pushed the poles about 150
degrees eastward.
In this time Tharsis had to be growing so it would
have been adding a lot of heat to the atmosphere, and initially along with the
newly formed Argyre Crater parts of South Polar Cap 2 would have overlaid these
hot areas, melting water and CO2 if frozen. This would thicken the atmosphere
and perhaps create snow or precipitation away from the heat. Tharsis and
Argyre, with Elysium Mons then could have supplied the heat for this
potentially habitable zone to last so long. This would also explain why Mars
has so many water signs when it should have been too cold for most of its
history. The overall temperature of Mars probably remained low, inhibiting the
destruction of olivine even in the presence of water.
South Polar Cap 3 assumed a position between the
Argyre and Isidis impact basins as each, being low gravity (low mass)
would tend to be close to this pole. When this occurred the Pole 3
positions would attain a stable configuration. Tharsis
was by this time near the Equator and South Polar Cap 3 was near the two main
negative masses of the Argyre Crater and Isidis Crater, with Utopia Crater a
lesser influence.
Interestingly, South Pole 3 coincides with an
area of heavy Noachian cratering[28]
and the second cratered area corresponds well with the opposite North Pole 3.
One likely explanation is that the polar ice protected the craters from
erosion, and when they were exhumed from the ice they remained in more pristine
condition. Pole 3 seems to have been stable for a long enough time for crater disparity. It also implies
at this time that the surface was being altered severely and other craters were
being buried or obliterated by lava flows.
Volcanism seems to follow the
polar wander, so is either related to the shock waves from impacts or is a late
stage effect, occurring in relation to degassing (geothermal activity) during
faulting of polar valleys. This would explain how volcanoes have apparently restarted in Martian
history and the surface is relatively young in parts.
Rift-like, passive, or
strike-slip valleys would be thus be overprinted by basal melting of icecaps
and related sublimation. Most large catastrophic flood (outburst) features
occur adjacent to these poles so may be triggered by increased geothermal heat.
Pole 3 likely remained
in a stable location through this resurfacing.
These crater areas are linked into what is termed
the Noachian age. Thus, after the Argyre impact may be regarded as the Hesperian,
obliterating much of the Noachian terrain except for these parts protected with
polar ice. Some other areas with Noachian craters are also found around
Margaritifer Sinus, implying the Polar Cap may have slowly moved and protected
other areas for a time in its path. In a later paper we will show a large
northern ice sheet or ocean would have sublimated after the
In moving from Pole 2 to Pole 3, the polar ice closely
follows and may have formed or modified the dichotomy boundary. The main dichotomy boundary is
seen between 180 degrees west and 90 degrees west, which is 270 degrees or ¾ of
a total possible boundary. The rest is taken up by the land mass of Tharsis
Montes, Syria Planum, etc.
South Polar Cap 2 moved from 12.7S 92.6W eastward to around 0S 330W, which is approximately
122 degrees of longitudinal movement or approximately 1/3 of the total great
circle. The opposite pole migrated from 12.7N 272.6W to 0S 150W, which is where the
dichotomy boundary ends against Olympus Mons, for a movement of 122 degrees.
This makes 244 degrees of movement over a dichotomy boundary of 270 degrees as
a polar wander path. The
rest can be explained by the width of the edge of South Polar Cap 3 at 330W in
Meridiani Planum, which makes it appear to extend further east. Thus virtually the entire visible
dichotomy boundary falls on the same line as the movement of Pole 2 to Pole 3.
The
Therefore if this polar path
is correct the
Early in the history of Mars
the
The polar wander path along the dichotomy boundary may
have been on a pre
existing slope, altering its shape with ice and water erosion. A Polar Cap
moving on a slope like this would tend to have a runoff of water heading north,
accounting for the smoother surfaces in Acidalia, Arcadis, Amazonis, and
Elysium Planitia.
THEMIS[31]
shows some evidence of such a runoff. Blue ice rich areas extend from the polar
path south west of Elysium Mons and north to a huge ice deposit encircling the
planet at 60N. This may have been part of the ancient northern ice sheet or
ocean. The heat from Elysium Mons here would have been melting part of the
moving polar cap and the water flowed north to the main ocean or ice sheet.
This THEMIS map should be looked at in conjunction with the previously
mentioned mola_regional.pdf.
Figure 2 shows a map of these ice rich areas. To make
them clearer in monochrome we have made the blue areas on the original appear
white.

A is the
approximate position of North polar Cap 2, where white ice deposits can be
seen. This trail moves to the right down to C, and on the left edge of the map
at J which would be North Polar Cap 3. North east of A there is a trail of ice
(more clear in the original map) shown by B. This connects to the large ice
deposit at H. In the center of the ice trail at B is Elysium Mons. This implies
that the heat from Elysium Mons melted water here to make the runoff to H, and
therefore that Elysium Mons was hot when the pole was at A. On the northern end
of this trail is where Viking 2 landed, and also the best example of Martian
spider ravines[32] [33]outside
of the current South Pole. The large ice deposit at South Polar Cap 3 in Meridiani Planum is shown
at I, and F an ice trail linking it to a northern ice sheet.
This is consistent
with the motion of the pole described here. At E we see a large ice trail
again, this time next to Olympus Mons and also east towards Pavonis Mons[34].
This implies some of the ice of North polar Cap 3 was melted by Olympus Mons
and moved north to the large ice area at G. E is also the location of Amazonis
and Arcadia Planitia which show signs of having been made smooth by water[35].
Photos M1900946 and
M1901546 show many volcanoes. These probably formed partially or wholly in
water. While this water may have come from melting ice it may indicate the area
was covered with ice or water. Olympus Mons and Tharsis would have been still
hot at this time, which helps to date these events.

Figure 3: the Northern lowlands
Figure 3 shows
dark areas on the Martian surface around the area of H in Figure 2. This
implies these dark areas may be associated with higher amounts of ice. The trails
of ice leading to these dark areas imply there was liquid water, which implies
some parts may have been a liquid ocean at this time.

Figure 4: Amazonis and
Figure 4 shows the dark areas coinciding with Amazonis
and Arcadia Planitia.

Figure 5: Map of Martian Iron at mid-latitudes.
In Figure 5 a map of Iron on mars from the Odyssey Gamma Ray Spectrometer[36] is shown. Here we have made the red, high iron areas on the original map black to be seen more clearly. E corresponds to Amazonis Planitia as a high Iron area. This is also associated with darker soil, has many water and ice signs, and is associated with the ice trail going northwards. So it is likely then some of the Iron may have been leached from the ground by water melted by Olympus Mons from North polar Cap 2. G shows the northern ice sheet is also Iron rich and connected by water or ice trails.
F shows an iron rich area coinciding with an ice rich area. Between K and B there is a trail of Iron from Meridiani Planum, or South polar Cap 3 up to Elysium Mons. This implies again that water from the pole moved north and north east to the large ice areas at H. C shows a large Iron deposit at North polar Cap 3.
It would be
difficult for this Iron to occur in these areas due to glaciation alone, so it is likely has some association with water. This then implies
a long-term northern ocean and ice sheet at the time Olympus Mons, with heat
provided along the
major north-south faults by Elysium and other
As the Polar Cap moved along the dichotomy boundary
from 2 to 3, new ice would tend to form on the ground ahead and melt on the ground
behind it as the temperatures changed. The ice in front would tend to freeze
into the soil and create a similar situation to the current Pole 5 where
approximately half or more of the soil is ice. When this eventually melted or
sublimated the soil in the ice should have moved down the slope and spread out.
If there was a high enough air pressure this should have created a seasonal
water flow into Acidalia Planitia and created the smooth surface. Amazonis
Planitia is thought to be flat from sedimentation or fluvial processes
according to Head[37].
Fuller et al[38] believe
the Alba Patera area was resurfaced volcanically and with fluvial sediments. A
periodically higher obliquity may have also created a water flow.
There are visible water channels in
Lunae Planum, Xanthe Terra, and Margaritifer Sinus, but these became less common as the Polar Cap moved eastwards. The edges of the (green) elevation in MOLA maps[39]
along this path may indicate the edges of the permanent ice cap cutting a flat
platform. The primary erosion
may have been caused by ice. Thus, at this stage Martian temperatures and air pressure were
possibly dropping after the Argyre impact.
The ice deposit at South Polar Cap 3 abuts a cliff to
the north, which is an extension of the dichotomy boundary. This ice then
implies that it is connected to the creation of this cliff and by extension
created the cliff of the dichotomy boundary as the Polar Cap moved. As water
ran down the slope at South Pole 3 it would have eroded the ground, but where
the ground was permanently frozen the ground would have been protected. This
should then give a boundary to the north of the moving Polar Cap where the
ground slopes more. Note also how South Polar Cap 3 also has an ice path at
approximately 345W connecting to the northern ice sheet or ocean. Water and ice
signs can be seen in narrow angle images from Malin Space Science Systems, such
as E0101857, E0300317, E0401351, E0401589, E0503396, E1600085, E1801705,
E2001051, E2100663, and E2301402.
These ice paths imply the terrain at the time was
conducive for water to flow into the ice rich areas at 60N, which implies these
ice rich areas were formed substantially from water runoff themselves. If they
were solely formed from ice deposition there would be no need for them to
connect in apparent water paths. Much of this water may have moved in
subsurface aquifers, which would explain a lack of rivers connecting to the ice
rich area. Much of the water or ice had to previously exist there for polar
wander to occur. This can easily be tested by simulating different depths of
ice to these lower areas, and seeing if it balances the planet sufficiently for
the polar path shown here to occur.
North Polar Cap 3 includes the area around Gusev
Crater and the Spirit Rover site. Pablo et al[40]
examined
Irwin et al[43]
describe Ma’adim Vallis as one of the largest valleys on Mars, believed to have
been carved from a large flood. This amount of water on North Polar Cap 3 fits
in well with the water signs at South Polar Cap 3. Water from North polar Cap 3
may have moved northwards into Arcadia Planitia.
Thomas-Keptra et al[44]
propose carbonate disks in ALH84001 may have formed in an area similar to
conditions found by the Rover Opportunity, which would link possible life signs
to these former poles.
This is also consistent with the idea of the water at
the Rover Opportunity site being from polar ice. Leask et al[45]
examine the Ravi Vallis and Aromatum Chaos areas and calculate the amount of
water that would have been involved. This would be the western edge of South
Polar Cap 3 and also represent an area the Polar Cap moved over.
Coleman[46]
also examined this area and believes an ice covered lake in Ganges Chasma
recharged the aquifer source. This is also consistent with the ice and water
coming from South Polar Cap 3. Woodworth-Lynas and Guigne[47]
examine the Kasei Valles area and believe water here was covered by ice floes.
This is on the western edge of South Polar Cap 3 and again implies large
amounts of water connected with the areas examined by
Barlow and Dohm[49]
examine Arabia Terra which is also on the edge of South Polar Cap 3 and
conclude a subsurface reservoir of ice and liquid water existed here. Dohm et
al[50]
also indicate the magnetic field may have been waning, consistent with the idea
of the
Arkani-Hamed and Boutin[51]
plotted magnetic poles which agree reasonably well with the movement of the
Polar Cap along the dichotomy boundary. The movement is roughly cycloidal, and
from this it may be possible to calculate how long it took the Polar Cap to
move from South Polar Cap 2 to 3. This assumes the magnetic Polar Cap may tend
to move around a given rotational Polar Cap position.
South Polar Cap 3 contains an area called the “Arabian Water-Rich Spot” with
16% water (Mitrofanov et al[52]). Dalton et al[53]
also found
evidence of water accumulation in the Flaugergues drainage divide, which is also on South Polar Cap 3.
In each case, rift-like fault systems and hence lakes were all adjacent to old polar caps. The valleys were then modified due
to sublimation of the icecaps and fluvial activity obscuring much of the
faulting (as with Chasma Australe).
If the degassing has a
volcanic relationship as implied by the polar-fault relationships, then SO2 may
the major gas released with the CO2 component being minor, related only to
initial defrosting. This seasonal defrosting would open pathways allowing
degassing to occur.
The high
iron and the sulfur content would thus result from volcanic degassing. The
In the
Siltstones may have formed in lakes and oceans
adjacent to polar caps. Some of these may have been carbonate rich (perhaps
varves) at the time. Thus, the icecap formed, then the rift valleys formed,
degassing and volcanism followed. The lakes may have existed in equilibrium
with the icecaps so a stable hydrological system must have existed, at least
near this polar pair.
Many of the rifts and major normal and strike slip
faults of mars occur adjacent to the polar caps. Thus, the crust has
preferentially fractured in polar regions. Degassing would occur due to increased
geothermal activity near hot spots or fractures in the mars crust.
The gases given off would be: CH4, SO2,
SO3, CO, CO2, H2O.
Some of the minerals formed due to hydrothermal
activity would be:
SO2 + 2H2O => H2SO4
+ H2
H2SO4
(sulfur) + CaCO3 (Limestone/calcium-rich silts) => CaSO4 (gypsum) + H2O + CO2
The rocks at the
CaSO4
(gypsum) + SiO2 + H2O => Mud
In arctic conditions mud may not always form. The
result may be very fine silt, which would mix with or cover any near surface
ice. If the temperature were to increase the ice just below the surface melt
and the material would flow to create the mud-like surface features we see at
2FeS
(pyrite) + 3H2O => Fe2O3 (pisolite) + 2H2S (rotten egg gas) + 1/2H2
The water would most likely then react to form
sulfates or revert to ice and be covered by or mixed with dust.
Astrobiology
It has been openly speculated
at the recent Rover Press Conferences about fossils[55]
possibly being found at the Rover sites, particularly at Meridiani. Also there
have been some objects found which some believe look like fossils. We will then
examine the astrobiological implications of this polar path.
The polar movement from Pole 2
to pole 3 as shown is accompanied by regular discharges or water, flooding, and
hematite deposits. Hematite[56]
has been found in the area of Pole 3, which is consistent with the having water
around a polar area. The area is believed to have been recently exhumed, by
Lane et al[57] which
is consistent with the Polar Cap moving and exposing this area. According to
Hynek Aram Chaos and Valles Marineris[58]
[59]
also have hematite deposits, which is consistent with the path of the moving
Polar Cap from South Polar Cap 2 to 3 giving water to create hematite. Hematite
has been found by Spirit at Gusev Crater on North Polar Cap 3. Catling and
McKay[60]
discuss possible biological aspects of hematite deposits. Cockell[61]
shows that life could survive under snow, which would protect from UV rays and
still allow photosynthesis.
Hynek et al[62]
say the erosion from water in Margaritifer Sinus lasted up to several hundred
million years. If the whole polar wander path from Margaritifer Sinus to
Meridiani Planum lasted only this long then it implies a habitable area may
then have existed on Mars for long enough for life forms to have evolved in
comparable time scales and environments as on Earth. Even in Margaritifer Sinus
it may have been wet enough for long enough for life to evolve substantially.
Life could have stayed close enough to the volcanoes for warmth, and the polar
path implies at least Tharsis was hot for several hundred million years or
more.
Several objects in particular seen at the
work is required to test this hypothesis.
Ausich et al[64]
in their Figure 5 shows some shapes which can be compared to Figures 6 and 7 in
this paper. Aronson and Blake[65]
show similar shapes in Polychaetes. Radwanska and Radwanski[66]
show more similar examples.

Figure 6[67]:

Figure 7[68]: The top of the fossil like shape appears to be
beginning to branch in two. There appears to also be a tail like shape.
Schelble et al[69]
discuss biological material often found associated with hematite, similar to shapes
seen by the Opportunity Rover. Figure 8[70]
shows a tubular shape reminiscent of a fossil or cryptobiotic soil crusts.