Lunar and Planetary Features
Printable Version
In this exercise you will be examining the relative ages of features on the Moon. After that you will
be looking at the different types of features seen on various bodies in the Solar System, such as
the Moon, the terrestrial planets (Mercury, Venus, Earth and Mars), and the satellites of some of
the outer planets.
Part I Stratigraphic Dating on the Moon
Stratigraphic dating is finding whether one feature is older than another based on the idea that
the older feature is UNDER the younger. Stratigraphic dating does NOT give an age in years. It
only gives the older/younger relationship. You will be doing stratigraphic dating on our Moon.
Read about the Moon in your textbook and get a feel for the appearance of different types of
feature. WebCT has a mini quiz to help you learn to identify the features on photos. Do take it
after reading about the types of lunar feature. Lunar features come in the following types.
Crater - Lunar craters result from things hitting the Moon. When things hit the Moon, they are
usually going so fast that they are destroyed and a crater about 10 times the size of the impactor
is made. Craters on the moon usually are circular with a raised edge. Small craters are rounded,
like a cereal bowl and have only a slight edge. Larger craters show a depressed center, distinct
raised edges and a central peak or central ring of mountains. The central or ring is due to
material splashing back after the impact.
Mare (plural maria) – Mare regions are areas where very runny lava has flowed. They look flat or
flat with small craters, like the surface of pudding. Usually the lava flow was triggered by an
impact breaking through the Moon’s crust. So look for a crater edge (or part of one) bounding the
mare. Mare regions are named mare (sea), oceanus (ocean), sinus(bay), palus (marsh), and
lacus (lake).
Basin (plural basins) are large craters surrounded by multiple rings and are usually filled in with
solidified lava.
Highland (or terra, plural terrae) form much of the rest of the surface. These are regions where
there are craters upon craters. There are so many craters that one is on top of another and the
circular edges are so disrupted that you cannot see the shapes. Look for just a jumble. The
highlands are large areas of the Moon. Do NOT use this word to identify specific features of the
Moon on your photos.
Mountain (features names Mons or Montes for a range of mountains)- Mountains on our Moon
are usually edges of old craters. Later lava flows have covered the surroundings, leaving just the
peaks. So mountains are always older than the surrounding mare regions. There are no real
volcano mountains. There are some subtle gently raised areas (called domes) and NO folded
mountains of the type seen on Earth.
Dorsum (pl Dorsa) or Wrinkle ridge-Wrinkle ridges are ridges in mare surfaces. They are
usually thought to be due to shrinkage of the Moon after the mare surface has solidified. Some
wrinkle ridges may be caused by lava flowing and leaving a puddle on the mare surface. Since
they are modifications of the mare surface, they are younger than the mare surface.
Rille or Rima- A rille is a valley on the Moon. We think that they are due to lava flowing on a
mare surface. The lava melts its way into the surface, leaving the valley. The outside top of the
lava trickle solidifies and the runny lava inside flows out. If the top collapses entirely a rille is left.(
If only part of the top collapses, a chain of craters called a catena can remain .The Moon has NO
rivers due to water that we know of.
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Catena (plural catenae) are chains of craters. On the Moon catenae can result from debris
thrown out when a large crater is formed. Or a catena can result when the top of a lava-carved
tube partly collapses.
Dome- Domes are volcanic mountains. They are very gently rounded. Domes on the Moon are
not given individual names (so you cannot look up dome in a list). They are named for the craters
that are near them. We have not seen any eruptions. They are not common.
Rupes (also known as Scarp) a cliff, one side high and the other low. Sometimes these are
edges of craters.
You can find a picture with examples of each of the features and a diagram of the ages from the
WebCT home page.
Documenting Relative Ages-Earth’s Moon
We have no radioactive dates for features of most of the bodies in the solar system. We do think
that the feature on top, is the youngest. When features do not overlap, we cannot always tell
which is older. On the Earth we might expect that an older feature might look more worn out, but
there is not so much erosion on other bodies.
You will be deciding on the relative ages of some features on TWO of the images of the Moon
provided. You may choose which ones.
To document the age relations, use the following notation.
a) Put older features to the left, younger to the right.
b) Connect items whose age relationship we know. This would occur because the younger
one is on top of the older.
c) Do NOT connect features whose age relationships are not known. This occurs when
features that do not touch or overlap.
Example (not any of the photos): You decide
that features B and D are under feature E. But
neither is under the other. So we don’t know
whether B or D is older, but we know that both
are older than E. Feature F is on top of E and
G on top of F. Feature H is on top of E, but not
on top of either F or G. Feature A is younger
than C and C is beneath J, but none of these
can be related to B or any of the others.
Identify the type of object for each and show
your conclusion for the age relations as shown.
(Remember that this is only an example). The
lines indicate the relationship between
features. To the right is younger. Vertically
displacements (up and down) with NO
connecting line indicate that we cannot tell the
age relationship.
As you can see, the relationships are NOT normally one straight line. It is important to indicate
which relationships cannot be specified. You may want to look again at the example on the
WebCT home page.
Use a small piece of paper or a 3x5 card to represent each of the features that you want to
explore. Work with your partners to establish which feature is on top, which on the bottom. Lay
out your cards in time order, with the leftmost position for the oldest and the rightmost for the
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youngest. If you cannot determine the relative age of two features, don’t connect them, put one
above the other.
You may either draw the diagrams on paper or do them on the computer. If you have a word
processor, you may be able to draw this kind of picture (I did) or space out the text. Or you can
use Power Point or Excel. The result will not be too large to email. If you don’t have any of these,
draw it on paper and mail it or drop it in the mailbox at my office.
Interpreting the Images
As you look at the images, be careful to distinguish what is sticking out and what is lower than the
surface. Often there is no easy way to tell without making assumptions. Look for shadows and
your knowledge that a crater will have a raised edge and a low middle to find the direction of the
sunlight. Once you know the direction the light is coming from, the shadows should be consistent
across the entire picture.
Moon pictures for finding the ages
You will be choosing two. Both pdf and gif versions are provided. The references on the same
line are for the same picture. (the high number ones are easier)
Pic 1
Pic 2
Pic 3
Pic 4
gif1
gif2
gif3
gif4
pdf1
pdf2
pdf3
pdf4
Pic 5
Pic 6
Pic 7
Pic 8
gif5
gif6
gif7
gif8
pdf5
pdf6
pdf7
pdf8
Questions 1 and 2 from the list at the back relate to Lunar Stratigraphic Dating.
End Part I
Part 2 Comparing Features on different Bodies in the Solar System.
The idea here is to look at maps of various objects in the solar system (NOT the EARTH) and find
features that are the same and different. For example, the Moon has craters. So find a named
crater on a map of the Moon and also find a crater on a map of a different object. Record the
name of each feature, its latitude and longitude.
A
You may use web sites and references other than the ones provided, but be sure to document
both the addresses and the information you found.
You choose which bodies to examine. If you work in pairs or groups, you must have at least ONE
body different from the ones your partner(s) has. Tell me who your partner(s) is/are, so I will know
to expect the same answers from more than one person. I don’t expect to see the same answers
from one semester to the next. So a good way to do it is to have two the same, then each
compare and contrast the final body.
What bodies are there to choose from?
The Jovian planets have no surface features visible, so don’t use them. On the other hand, their
satellites have fascinating features. There is a great amount of data about Jupiter’s Galilean
satellites (Io, Europa, Ganymede and Callisto) because the Galileo spacecraft observed them
from 1994 to 2003. Some of the satellites of Saturn, Uranus, and Neptune were observed by
Voyager II, so there is some information about them. Pluto, and its moon Charon, have only
images from the vicinity of Earth, so no distinct features are visible. Don’t choose any of the
bodies where nothing much is seen. Do not use the Earth.
Many of the photos and maps that have come from the space program are available from the
Internet. A selection of these images is available in the folder provided with this lab. Other
references are given in the references section. You should be able to do most of your work
without printing the maps.
Often you can tell the type of feature from the name, much as you know that the Pacific
Ocean is water because of the word ocean or that Mount Shasta is a mountain. Other
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planets have some feature names that are uncommon on the Earth. The table of features
near the end lists some feature types.
Types of data available.
Most images are made with digital cameras or television cameras. They were transmitted from a
spacecraft near the body in question (some orbited the body, others flew by and went on.) There
are some old film photos of the Moon that have later been digitized.
Some images are mosaics of many pictures. Notably there are mosaics of the Moon’s polar
regions from the Clementine spacecraft and mosaics of images of Mercury from Mariner 10.
These pictures have inconsistent lighting. That is, the sunlight seems to come from a variety of
directions. If you use these pictures, compare lighting over only small regions of the image. Small
parts of the image are taken in separate pictures, so they should have consistent lighting.
The Venus images are radar images. They are made by bouncing radio waves off the surface
and measuring the time that the radio waves take to return to the spacecraft. The time depends
on the distance to the surface, so it is a direct measurement of the height at the surface. The
brightness or darkness is decided by how much of the radio wavelengths are reflected. It doesn’t
correspond to anything we see with our eyes. When we have an image of Venus, it has been
created by faking shadows to give an impression of depth in the two dimensional picture. Only
radar images are available from space because Venus’ atmosphere does not allow much visible
light to get through.
Topographic maps are maps of the altitude, height above a reference level. Color indicates the
depth. There is no sea level on any planet except Earth, but there is an average level. You may
be wondering what happened to the topographic maps of the Earth. There are lots and lots of
them, but they are for sale from the US Geological survey. They can even show individual
buildings in rural areas.
Name___________
Group Members__________________
(don’t forget the objective and conclusion)
1. Assess the relative ages of the features in the two of the images given (both the moon) Try to
draw circles around the craters on the image to assist you in getting the order correct. There are
several images on the disk. For each of the images, identify the features you are assessing and
make a diagram in the form described above.
2. Pretend that you are explaining how to do number 1 to one of your friends. Describe the
process of how your decide which feature is older and which is younger. Do the description for a
general picture, not any specific one.l
3. Decide on your three bodies. If you are working in a group, be sure that each person chooses
two of the same bodies and one that is unique to each person. Before deciding on the bodies,
take a look at the resources available and be sure that you can find topographic maps and
images for all three.
4. Find Similar Features on Different Bodies.
Find at least four types of feature among your bodies and at least three features (of different
types) on each planet. The idea is to try to find some similar and some different kinds of feature
on the different bodies. You may choose types from the list above or find additional features
associated with descriptions of the bodies.
Use a table like the one below to document your
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work. If you don’t want this one, you may write it on paper or in Word or in Excel. Fill in at least
12 features total. Read the latitude and longitude from the map.
Example; If you were doing the Earth, you might find the type of object is a volcano. A specific
feature name would be Mt. Etna, and its latitude and longitude would be 15 oE, 38oN. Now try to
find the same kind of feature on another body.
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Name of body
Reference
used
Type of Feature
Feature
Feature
Feature
Lat.
Long.
Feature
Lat.
Long.
Feature
Lat.
Long.
Feature
Lat.
Long.
Feature
Lat.
Long.
Feature
Lat.
Long.
Feature
Lat.
Long.
Feature
Lat.
Long.
Feature
Lat.
Long.
Feature
Lat.
Long.
Feature
Lat.
Long.
Feature
Lat.
Long.
Feature
Lat.
Long.
Feature
Lat.
Long.
Feature
Lat.
Long.
Feature
Lat.
Long.
Lat.
Long.
Lat.
Long.
Reference(s):
5) Compare the appearance of one type of feature as it appears on two of your bodies. Tell the
type of feature and describe the similarities and differences.
6) Did you find any type of feature of that is on only ONE of the bodies? What kind of feature is it?
(it probably would NOT be in your table)
7) Topographic maps show the height of features above and below some reference level. There
are topographic maps for most of the bodies. Some of these maps are made with radar or laser
radar. The spacecraft would bounce light, either radio frequency or visible light off the surface and
measure the time for the signal to return.
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Name of body 
Color for the highest
features
Height for the highest
features
Example
of
high
feature
Color for the lowest
feature
Height (below level)
for the lowest level
Example of
low
feature
Reference
you used.
for
Feature name
Feature name
Feature name
Lat.
Long.
Lat.
Long.
Lat.
Long.
Feature name
Feature name
Feature name
Lat.
Long.
Lat.
Long.
Lat.
Long.
map
Moon pictures for finding the ages
You will be choosing two. Both pdf and gif versions are provided.
line are for the same picture. (Higher number pictures are easier)
Moon
Pic 1 gif
pdf
Pic 5 gif
Pic 2 gif
pdf
Pic 6 gif
Pic 3 gif
pdf
Pic 7 gif
Pic 4 gif
pdf
Pic 8 gif
The references on the same
pdf
pdf
pdf
pdf
Maps to use for features and topographic information
Amalthea topographic jpg pdf
Ariel photographs of polar region with names jpg pdf
Io pdf
Janus topographic jpg pdf
Mars topographic jpg pdf
Mars MOLA (laser altimeter data, much like topographic) pdf
Mars topographic with names http://ralphaeschliman.com/
Miranda map
jpg pdf
Moon with names
(if type of feature is not mentioned, it is a crater) names http://ralphaeschliman.com/
Proteus topographic map jpg pdf
Triton
Map with names, not topo http://www.solarviews.com/eng/trimap.htm
Venus topographic map with names
Venus topographic and relief maps with names http://ralphaeschliman.com/
Public Web sites, subject to change. Please report broken links and better
references
Multiple bodies
http://www.lpi.usra.edu/
Nice clickable pictures with descriptions. Not a map and doesn’t have grid
http://pds.jpl.nasa.gov/planets/welcome.htm
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These aren’t really maps, they are texture pictures. They don’t give sizes
http://maps.jpl.nasa.gov/
So-so planet pics
http://www.solarviews.com/eng/homepage.htm
Pictures by type, keep looking there are maps with coordinates
(the easiest place to find topographic maps)
http://www.solarviews.com/cap/index/index.html
Ok pics, not good search
http://www.jpl.nasa.gov/
http://maps.jpl.nasa.gov/
Maps customizable, but not easy to use
http://pdsmaps.wr.usgs.gov/maps.html
Includes lots of photos and a section concerning maps. These are mostly maps of smaller bodies.
Be sure to use only maps based on actual data, not fictional ones. The maps are ok for small
bodies, they don’t have enough detail to use for bodies like the Moon and Mars. This site is good
for having images of lots of features by type of feature.
www.solarview.com
Mercury
Mercury has been only partially mapped, because only Mariner 10 has flown around it.
Look in one of the multiple body sites
Venus
Venus’ maps are all from radar, because regular light cannot go through the atmosphere.
This is a clickable map, but has no names and is black and white
http://www-pdsimage.jpl.nasa.gov/PDS/public/magellan/midrcd_query3.html
Mars
Clickable low resolution map. Black and white with dark/light
http://cmex.arc.nasa.gov/Atlas96/Atlas96.htm
The following has a blah map and can be clicked to give a lot of Viking photos of the region. The
photos are nice, but have little info, just a number.
http://barsoom.msss.com/http/vikingdb.html
MOC (Mars Orbiter Camera) clickable map
http://barsoom.msss.com/mars_images/moc/moc_atlas/
a much better image
http://barsoom.msss.com/mars_images/moc/moc_atlas/indexfull.jpg
Rotating clickable Mars
http://www.roving-mouse.com/planetary/Mars/Atlas/clickable-globe.html
Mars exploration home page. Not great for images and maps. Gets to the mapping program
and other flow charts of science http://cmex.arc.nasa.gov/CMEX/index.html start here and go
into atlas then image
Moon
Moon map with names as you scroll, not good resolution
http://www.penpal.ru/astro/
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Lunar Atlas excellent pictures, better interface, for clicking
http://www.lpi.usra.edu/research/cla/menu.html
Clementine images (pictures, not maps)
http://cass.jsc.nasa.gov/pub/research/clemen/clemen.html
TABLE OF FEATURE TYPES
Feature
(singular, Description
then plural form)
Albedo Feature
Albedo means the fraction of the light that is reflected. An
albedo feature would be color on the surface (but not a
height variation).
Astrum, astra
Radial-patterned features on Venus
Catena, catenae
Chain of craters
Cavus, cavi
Hollows, irregular steep-sided depressions usually in
arrays or clusters
Chaos
Distinctive area of broken terrain
Chasma, chasmata
A deep, elongated, steep-sided depression
(think
chasm)
Colles
Small hills or knobs
Corona, coronae
Ovoid-shaped (oval or ellipsoidal) feature
Crater, craters
A circular depression , possibly with a raised edge
Dorsum, dorsa
Ridge
Eruptive center
Active volcanic centers on Io , Jupiter’s moon
Facula, faculae
Bright spot
Farrum, farra
Pancake-like structure, or a row of such structure
Flexus, flex\-us
A very low curvilinear ridge with a scalloped pattern
Fluctus, fluct\-us
Flow terrain
Fossa, fossae
Long, narrow, shallow depression
Labes, lab\-es
Landslide
Labyrinthus,
Complex of intersecting valleys
labyrinthi
Lacus(1)
"Lake"; small plain (not necessarily a lake with water)
Landing site name
Lunar features at or near Apollo landing sites
Large ringed feature Cryptic ringed features
Lenticula, lenticulae
Small dark spots on Europa
Linea, lineae
A dark or bright elongate marking, may be scalloped
pattern
Macula, maculae
Dark spot, may be irregular
Mare(1), maria
"Sea"; large circular plain (none known with water)
Mensa, mensae
A flat-topped prominence with cliff-like edges
Mons, montes
Mountain
Oceanus(1)
A very large dark area on the moon
Palus(1), paludes
"Swamp"; small plain
Patera, paterae
An irregular crater, or a complex one with scalloped
edges
Planitia, planitiae
Low plain
Planum, plana
Plateau or high plain
Plume
Promontorium(1),
promontoria
Regio, regiones
Reticulum, reticula
Planetary Features Lab
Abbreviation
AL
AS
CA
CB
CH
CM
CO
CR
AA
DO
ER
FA
FR
FE
FL
FO
LA
LB
LC
LF
LG
LE
LI
MA
ME
MN
MO
OC
PA
PE
PL
PM
PU
"Cape"; headland
PR
A large area marked by reflectivity or color distinctions
from adjacent areas, or a broad geographic region
reticular (netlike) pattern on Venus
RE
RT
9
Rima, rimae(1)
Fissure (crack or narrow valley)
Rupes, rup\-es
Scarp
(cliff, but larger and long)
Scopulus, scopuli
Lobate or irregular scarp
Sinus
"Bay"; small plain
Sulcus, sulci
Subparallel furrows and ridges
Terra, terrae
Extensive land mass
Tessera, tesserae
Tile-like, polygonal terrain
Tholus, tholi
Small domical mountain or hill
Undae
Dunes
Vallis, valles
Valley
Vastitas, vastitates
Extensive plain
(1)
(1) Used only on the Moon
This nomenclature write up is basically from
http://wwwflag.wr.usgs.gov/USGSFlag/Space/nomen/nomen.html
RI
RU
SC
SI
SU
TA
TE
TH
UN
VA
VS
As you look at the pictures and maps of other planets and moons, you will find that there are
themes for the names. Each planet and moon has its own convention. On Venus, for example,
the names are women or goddesses. On Mercury, the names are for people who were in the arts
and music
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