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MarsPHYS 178 – 2008 Week 4, Part 2
!
Lowell’s Mars Globe
One of the remarkable globes of Mars prepared by
Percival Lowell, showing a network of dozens of canals,
oases, and triangular water reservoirs that he claimedwere visible on the red planet. (Lowell Observatory)
2 Table 9-1, p.199
3
Mars - HST This NASA Hubble SpaceTelescope view of the planet Mars is the
clearest picture ever taken from Earth. The
picture was taken on February 25, 1995,
when Mars was at a distance of 100 millionkm from Earth. Because it is spring in Mars'
northern hemisphere, much of the carbon
dioxide frost around the permanent water-icecap has sublimated, and the cap has receded
to a core of solid water-ice several hundred
miles across.
Towering 25 km above the surrounding
plains, volcano Ascraeus Mons pokes above
the cloud deck near the western or limb. Thisextinct volcano, measuring 402 km across,
was discovered in the early 1970s by Mariner
9 spacecraft. Other key geologic featuresinclude (lower left) the Valles Marineris, an
immense rift valley the length of the
continental United States. Near the center ofthe disk lies the Chryse basin made up of
cratered and chaotic terrain.
The oval-looking Argyre impact basin(bottom), appears white due to clouds or
frost. Seasonal winds carry dust to form
striking linear features reminiscent of thelegendary martian "canals." Many of these
"wind streaks" emanate from the bowl of
these craters where dark coarse sand isswept out by winds. Dark areas, once
misinterpreted as regions of vegetation by
several early Mars watchers, are areas ofcoarse sand that is less reflective than the
finer, lighter dust. Seasonal changes in the
surface appearance occur as winds move thedust and sand around.
4
Mars - Happy Face Crater
The story of the Mars Orbiter Camera (MOC) onboard the
Mars Global Surveyor (MGS) spacecraft began with a
proposal to NASA in 1985. The first MOC flew on Mars
Observer, a spacecraft that was lost before it reached thered planet in 1993. Now, after 14 years of effort, a MOC
has finally been placed in the desired mapping orbit. The
MOC team's happiness is perhaps best expressed by theplanet Mars itself. On the first day of the Mapping Phase
of the MGS mission--during the second week of March
1999--MOC was greeted with this view of "Happy FaceCrater" (center right) smiling back at the camera from its
location on the east side of Argyre Planitia. This crater is
officially known as Galle Crater, and it is about 215kilometers (134 miles) across. The picture was taken by
the MOC's red and blue wide angle cameras. The bluish-
white tone is caused by wintertime frost. Illumination isfrom the upper left.
5 Fig 9-13, p.206
Mars Globe from Radar These globes are highly precise topographic maps, reconstructed from
millions of individual elevation measurements with the Mars Global Surveyor spacecraft. Color is usedto indicate elevation. The hemisphere on the left includes Olympus Mons, the highest mountain on
Mars, while the hemisphere on the right includes the Hellas basin, which has the lowest elevation on
Mars. (JPL/NASA)
6
Regional Topographic Views of Mars fromMOLA
With one year of global mapping of the MarsGlobal Surveyor mission completed, the
MOLA dataset has achieved excellent spatial
and vertical resolution. This map has been
produced from the altimetric observationscollected during MOLA's first year of global
mapping and provide a variety of regional
topographic views of the Martian surface.The maps were compiled from a data base of
266.7 million laser altimetric measurements
collected between March 1, 1999 andFebruary 29, 2000. In each map the spatial
resolution is approximately 1/16° by 1/32°
(where 1° on Mars is about 59 km) and thevertical accuracy is approximately 1 meter.
PIA01049
7Olympus Mons - Altimetry
8 Fig 9-14, p.206
Olympus Mons The largest volcano on Mars, and probably in the solar system in a rendering based
on data from the Mars Orbiter Laser Altimeter. The caldera, the circular opening at the top, is 65 km
across, about the size of Los Angeles. Note the extensive clouds over the lower slopes of the volcano.(Kees Veenenbos)
9
Elysium Chasm - Altimetry
Comparison of the cross-sectional relief of the deepest portion of the Grand Canyon (Arizona) on Earth versus a Mars
Orbiter Laser Altimeter (MOLA) view of a common type of chasm on Mars in the western Elysium region. The Grand
Canyon topography is shown as a trace with a measurement every 90 m along track, while that from MOLA reflectsmeasurements about every 400 m along track. The slopes of the steep inner canyon wall of the Martian feature exceed
the angle of repose, suggesting relative youth and the potential for landslides. The inner wall slopes of the Grand Canyon
are less than those of the Martian chasm, reflecting the long period of erosion necessary to form its mile-deep characteron Earth.
10
Valles Marineris
This high resolution picture (right) of the Martian surface was obtained by the Mars Orbiter Camera (MOC). Seen in this view are aplateau and surrounding steep slopes within the Valles Marineris, the large system of canyons that stretches 4000 km along the
equator of Mars. The image covers only 9.8 km by 17.3 km but captures features as small as 6 m across. The highest terrain in the
image is the relatively smooth plateau near the center. Slopes descend to the north and south in broad, debris-filled gullies withintervening rocky spurs. Multiple rock layers, varying from a few to a few tens of meters thick, are visible in the steep slopes on the
spurs and gullies. Layered rocks on Earth form from sedimentary processes and volcanic processes. Both origins are possible for
the Martian layered rocks seen in this image. In either case, the total thickness of the layered rocks seen in this image implies acomplex and extremely active early history for geologic processes on Mars. The left and center 'context' images are Viking mosaics.
11 Fig 9-15, p.207
Martian Landslides
This Viking orbiter image shows one section of the Valles Marineris canyon system. The canyon walls are about 100
km apart here. Look carefully and you can see enormous landslides whose debris is piled up underneath the cliff walls,which tower some 10 km above the canyon floor. (NASA/USGS)
12Fig 9CO,
p.194
Heavily Eroded Canyonlands on Mars This Viking spacecraft view looks down
on a small part of the Valles Marineris canyon complex and shows an area about60 km across(NASA/USGS, courtesy of Alfred McEwen)
13
Geologic 'Face on Mars'Formation
NASA's Viking 1 Orbiterspacecraft photographed
this region in the northern
latitudes of Mars on July25, 1976 while searching
for a landing site for the
Viking 2 Lander. Thespeckled appearance of the
image is due to missing
data, called bit errors,
caused by problems intransmission of the
photographic data from
Mars to Earth. Bit errorscomprise part of one of the
'eyes' and 'nostrils' on the
eroded rock that resemblesa human face near the
center of the image.
Shadows in the rockformation give the illusion
of a nose and mouth.
Planetary geologistsattribute the origin of the
formation to purely natural
processes. The feature is
1.5 kilometers across, withthe sun angle at
approximately 20 degrees.
The picture was taken froma range of 1,873
kilometers.
PIA01141
14 p.215
The “Face on Mars” isseen here with ten times
better resolution from
Global Surveyor. The
image has beenprocessed to simulate
the lighting conditions of
the Viking image foreasier comparison.
(NASA/Malin SpaceScience Systems)
15
Teardrop Islands
The water that carved the channels to the north andeast of the Valles Marineris canyon system had
tremendous erosive power. One consequence of
this erosion was the formation of streamlined islandswhere the water encountered obstacles along its
path. This image shows two streamlined islands that
formed as the water was diverted by two 8-10-kilometer-diameter craters lying near the mouth of
Ares Vallis in Chryse Planitia. The water flowed from
south to north (bottom to top of image). Note that theejecta blanket of the third large crater (located at the
tapered downstream tail of the uppermost island) is
uneroded, an indication that this crater formedsometime after the channel was active. The height
of the scarp surrounding the upper island is about
400 meters, while the scarp surrounding thesouthern island is about 600 meters high. (From
Mars Digital Image Map, image processing by Brian
Fessler, Lunar and Planetary Institute.)
16
Flow around Dromore Crater,
Chryse Planitia, Mars
Viking 1 Orbiter image ofDromore Crater in Chryse
Planitia, Mars. Flow from the left
(west) appears to have brokenthrough low points on the ridge
and eroded the channels as it
flowed around the 15 kmdiameter crater. The image is
approximately 50 km across.
North is at about 1:30. (VikingOrbiter 020A62)
17
Yuty - Rampart Crater withFluidized Ejecta (22°N,34°W)
The ejecta deposits around theimpact crater Yuty (18 km in
diameter) consist of many
overlapping lobes. Craters withthis type of ejecta deposit are
known as rampart craters. This
type of ejecta morphology ischaracteristic of many craters
at equatorial and midlatitudes
on Mars but is unlike that seen
around small craters on theMoon. This style of ejecta
deposit is believed to form
when an impacting objectrapidly melts ice in the
subsurface. The presence of
liquid water in the ejectedmaterial allows it to flow along
the surface, giving the ejecta
blanket its characteristic,fluidized appearance. (Viking
Orbiter image 3A07.)
18
Parana Valles
drainage system
in MargaritiferSinus, Mars
This Viking 1Orbiter image
shows the Parana
Valles, a digitatevalley network in
the Margaritifer
Sinus region ofMars. These
networks look
similar to river
drainage networkson Earth, and
were presumably
formed by runningwater sometime in
Mars' past. This
image is about250 km across.
North is at ~10:30.
(Viking Orbiter084A47)
19
Mars - Chaotic Terrain
Like many other channels that empty into the northern plains of Mars, Ravi Vallis originates in a region of collapsed anddisrupted ("chaotic") terrain within the planet's older, cratered highlands. Structures in these channels indicate that they were
carved by liquid water moving at high flow rates. The abrupt beginning of the channel, with no apparent tributaries, suggests
that the water that carved the channel was released under great pressure from beneath a confining layer of frozen ground. Asthis water was released and flowed away, the overlying surface collapsed, producing the disruption and subsidence shown
here. Three such regions of chaotic collapsed material are seen in this image, connected by a channel whose floor was
scoured by the flowing water. The flow in this channel was from west to east (left to right). This channel ultimately links up witha system of channels that flowed northward into Chryse Basin. (Image processing by Brian Fessler, LPI)
20 Fig 9-23, p.212
Evidence of Liquid Water on MarsThis intriguing channel, called Nanedi Valles resembles
Earth river beds in some (but not all) ways. The tight curves
and terraces seen in the channel certainly suggest thesustained flow of a fluid like water. The channel is about 2.5
km across and the entire Global Surveyor image is 10 km
wide. (NASA/Malin Space Science Systems)
21 Fig 9-24, p.213
Outflow Channels
Here we see a region of large outflow
channels, photographed by Viking.These features appear to have been
formed in the distant past from massive
floods of water. The width of this image
is about 150 km. (NASA/JPL)
22 Fig 9-22, p.212
Runoff Channels These runoff channels in the old martian highlands are interpreted as the valleys of
ancient rivers fed either by rain or underground springs. The width of this image is about 200km.(NASA/from Mars Digital Image Map, processing by Brian Fessler, LPI)
23 Fig 9-25b, p.213
Recent Gullies on MarsGullies on the wall of
Newton Crater. Each
image is about 2 kmacross.
(NASA/JPL/USGS)
24 Fig 9-26, p.213
Stratification in the
Martian Crust
As many as 100layers can be seen in
this high-resolution
photo of a wind-eroded mesa within
the Valles Marineris
canyons. Manygeologists interpret
this photo as
evidence for layers ofsediment deposited in
an ancient martian
sea. The width of theimage is only 1.5 km.
(NASA/JPL/USGS)
25 Fig 9-25a, p.213
Recent Gullies on
MarsGullies on a cliff near
the South Polar Cap.
(NASA/JPL/USGS)
26 Fig 9-19, p.209
Sand Dunes on Mars
These dark dunes in the interior of ProctorCrater overlay a lighter sandy surface. Each
dune in this high-resolution view is about 1 km
across. (NASA/JPL/USGS)
27 Fig 9-18, p.209
Tracks of Dust Devils
This high-resolution
photo from MarsGlobal Surveyor shows
the dark tracks of
several dust devils thathave stripped away a
thin coating of light-
colored dust. This viewis of an area about 3
km across. Dust devils
are one of the most
important ways thatdust gets redistributed
by the martian winds.
(NASA/JPL/USGS)
28
Mars - North Polar Cap
These images were created
by assembling mosaics of
three sets of images takenby HST in October, 1996
and in January and March,
1997 and projecting them toappear as they would if seen
from above the pole. The
resulting polar maps beginat 50 degrees N latitude and
are oriented with 0 degrees
longitude at the 12 o'clock
position. This series ofpictures captures the
seasonal retreat of Mars'
north polar cap. October1996 (early spring in the
Northern hemisphere): In
this map, assembled fromimages obtained between
Oct. 8 and 15, the cap
extends down to 60 degreesN latitude, nearly it's
maximum winter extent. A
thin, comma- shaped cloudof dust can be seen as a
salmon-colored crescent at
the 7 o'clock position. Thecap is actually fairly circular
about the pole at this
season; the bluish "knobs"
where the cap seems toextend further are clouds
that occurred near the edges
of the sets of images used tomake the mosaic.
29 Fig 9-21, p.211
Layers at the Martian North Pole
The small inset in the left image shows a map of the residual north polar cap of Mars, which is about 1000 kmacross and composed of water ice. The small black box in the middle of the map shows the area covered in the
tilted Viking orbiter image at left. The box in that image shows the area of the Global Surveyor high-resolution
image at right. On the right image, we see a slope on the edge of the permanent north polar cap, with dozens of
layers visible—some thinner than 10 meters. (NASA/JPL/Malin Space Science Systems)
30 Fig 9-20, p.210
Martian Meteorite
A fragment of basalt ejectedfrom Mars in a crater-forming
impact, that eventually arrived
on the Earth’s surface.
(NASA/JSC)
31 Fig 9-16a, p.208
Three Martian Landing Sites The Mars landers -- Viking 1 in Chryse, Viking 2 in Utopia, and Pathfinder in Ares Valley --
all photographed their immediate surroundings. It is apparent from the similarity of these three photos that each spacecraft toucheddown on a flat windswept plain littered with rocks ranging from tiny pebbles up to meter-size boulders. It is probable that most of
Mars looks like this on the surface. (NASA/JPL/USGS)
32 Fig 9-16b, p.208
Viking 2 in Utopia
33
Sojourner on Pathfinder
The Sojourner rover and undeployed ramps onboard the Mars Pathfinder spacecraft can be seen in in this image, by the Imagerfor Mars Pathfinder (IMP) on July 4 (Sol 1). This image has been corrected for the curvature created by parallax. The microrover
Sojourner is latched to the petal, and has not yet been deployed. The ramps are a pair of deployable metal reels which will provide
a track for the rover as it slowly rolls off the lander, over the spacecraft's deflated airbags, and onto the surface of Mars. Pathfinderscientists will use this image to determine whether it is safe to deploy the ramps. One or both of the ramps will be unfurled, and
then scientists will decide whether the rover will use either the forward or backward ramp for its descent.
34
Sojourner at Yogi In this scene showing the rover deployed at rock Yogi, the colors have been enhanced to bring out
differences. Yogi (red arrow), one of the large rocks with a weathered coating, exhibits a fresh face to the northeast,
resulting perhaps from scouring or from fracturing off of pieces to expose a fresher surface. Barnacle Bill and Cradle (bluearrows) are typical of the unweathered smaller rocks. During its traverse to Yogi the rover stirred the soil and exposed
material from several cm in depth. During one of the turns to deploy Sojourner's Alpha Proton X-Ray Spectrometer (inset
and white arrow), the wheels dug particularly deeply and exposed white material. The lander's rear ramp, which Sojournerused to descend to the Martian surface, is at lower left.
35
D-Star Panorama by Opportunity
NASA's twin Mars Exploration Rovers have been getting smarter as they get older. This view from Opportunity shows thetracks left by a drive executed with more onboard autonomy than has been used on any other drive by a Mars rover.
Opportunity made the curving, 15.8-meter (52-foot) drive during its 1,160th Martian day, or sol (April 29, 2007). It was testing
a navigational capability called "Field D-star," which enables the rover to plan optimal long-range drives around anyobstacles in order to travel the most direct safe route to the drive's designated destination. Field D-Star and several other
upgrades were part of new onboard software uploaded from Earth in 2006. Victoria Crater is in the background, at the top of
the image. The Sol 1,160 drive began at the place near the center of the image where tracks overlap each other. Tracksfarther away were left by earlier drives nearer to the northern rim of the crater. For scale, the distance between the parallel
tracks left by the rover's wheels is about 1 m from the middle of one track to the middle of the other. The rocks in the center
foreground are roughly 7 to 10 cm tall. The rover could actually drive over them easily, but for this test, settings in theonboard hazard-detection software were adjusted to make these smaller rocks be considered dangerous to the rover. The
patch of larger rocks to the right was set as a keep-out zone. The location from which this image was taken is where the
rover stopped driving to communicate with Earth. A straight line from the starting point to the destination would be 11 m.Opportunity plotted and followed a smoothly curved, efficient path around the rocks, always keeping the rover in safe areas.
NASA/JPL-Caltech/Cornell University PIA10213
36
Phoenix Mission Lander on Mars, Artist's Concept
The Phoenix Mission is the first project in NASA's openly competed program of Mars Scout missions. The mission's plan
is to land in icy soils near the north polar permanent ice cap of Mars and explore the history of the water in these soils and
any associated rocks, while monitoring polar climate. The spacecraft and its instruments are designed to analyze samplescollected from up to a half-meter deep by a robotic arm. The arm extends forward in this artist's concept of the lander on
Mars. (NASA/JPL )
PIA07247
37
'Snow White' Trench
This image was acquired by
NASA's Phoenix MarsLander's Surface Stereo
Imager on Sol the 43rd Martian
day after landing (July 8,
2008). This image shows thetrench informally called "Snow
White."
Two samples were delivered to
the Wet Chemistry Laboratory,
which is part of Phoenix'sMicroscopy, Electrochemistry,
and Conductivity Analyzer
(MECA). The first sample was
taken from the surface areajust left of the trench and
informally named "Rosy Red."
It was delivered to the WetChemistry Laboratory on Sol
30 (June 25, 2008). The
second sample, informallynamed "Sorceress," was taken
from the center of the "Snow
White" trench and delivered tothe Wet Chemistry Laboratory
on Sol 41 (July 6, 2008).
NASA/JPL-Caltech/University of
Arizona/Texas A&M University
PIA11010:
38
Color View of 'Rosy Red' Delivered to TEGANASA's Phoenix Mars Lander's Surface Stereo Imager took this false color
image on Sol 72 (August 7, 2008), the 72nd Martian day after landing. It
shows a soil sample from a trench informally called "Rosy Red" after beingdelivered to a gap between partially opened doors on the lander's Thermal
and Evolved-Gas Analyzer, or TEGA.
NASA/JPL-Caltech/University of Arizona/Texas A&M UniversityPIA11023
39
40 Table 9-2, p.203
41 The New Solar System ch13
42 The New Solar System ch13
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