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. 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.
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
presentation with examples of each of the features from lunar
example.
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 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.
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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.
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As
you can see, the relationships are NOT normally one straight line. It is important
to indicate which relationships cannot be specified. NOT specifying a relative age is part of the
science, not a failure.
It can help to use a small piece of paper or a 3x5
card to represent each of the features. Work with your partners to establish
which feature is on top, which on the bottom. Lay out your cards, overlapping
the one(s) that do overlap. Arrange them in time order, with the leftmost
position for the oldest and the rightmost for the youngest. If you cannot
determine the relative age of two features, don’t connect them, put one above
the other. The point of using the cards
is to be able to reorganize the order easily, without erasing. Then copy the arrangement of the cards.
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)
Question: Write an explanation of
how to do this part. Explain as though you are talking to a friend on the
phone.
Part 2 Comparing Features on different Bodies in
the Solar System.
The idea of
this part is to compare and contrast the appearance, size
etc of features on three different
objects in the solar system. You might use the list of types of feature in part
1 of this write up or you could go to http://planetarynames.wr.usgs.gov/index.html and follow the link for “descriptor terms”.
For example, you might try to compare the appearance of craters on the Moon,
Mars and Venus. For each feature that you find, record the name (like
Copernicus Crater on the Moon) and its latitude
and longitude. Y
To find the examples, you can
use maps of the planets and moons (like the ones identified at the end of this
write up) or you might go to http://planetarynames.wr.usgs.gov/index.htm
and enter the word “crater”. You will get a list of individual craters with an
indication of the object on which each feature is found. There is a magnifying
glass icon to indicate whether there is an image of the feature. Some of theses
“images” are on a scale that barely shows the feature, so be prepared to look
at several features to find worthwhile
pictures.
Don’t expect to get all the
same features for whatever three objects you choose. That is why there are extra spaces in the table, but be certain to find at least 4 different
types of feature and at least 12 total items.
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.
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.
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.
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.
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Name of body®
Type of Feature¯
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Feature
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Reference(s) used->
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Question: 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.
Question: 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)
Part 3
Topographic Maps 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.
On the topographic maps, color indicates the height
or 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. There are links to topographic maps below. Not all of the
maps have names for the features. If that is the case, no names are
expected. The bodies do NOT need to be
the same ones as in part 2.
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Name of body ®
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Color for the highest features
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Height for the highest features
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Example of high feature
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Feature name
Lat.
Long.
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Feature name
Lat.
Long.
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Feature name
Lat.
Long.
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Color for the lowest feature
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Height (below level) for the lowest level
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Example of
low feature
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Feature name
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Feature name
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Feature name
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Reference for map you used.
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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. (Higher number pictures are easier)
Moon
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 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
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/
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
http://ralphaeschliman.com/id25.htm
includes topographic map with names and altitude scale
Mars
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)
http://barsoom.msss.com/mars_images/moc/moc_atlas/
look then, click where it says “click here”
Mars
exploration home page.
http://marsprogram.jpl.nasa.gov/gallery/images.html
atlas and images of features
Moon
Moon map with names as you scroll,
not good resolution
http://www.penpal.ru/astro/
Lunar Atlas excellent
pictures, better interface, for clicking
http://www.lpi.usra.edu/research/cla/menu.html
Clementine images
(pictures, not maps)
http://www.cmf.nrl.navy.mil/clementine/
TABLE
OF FEATURE TYPES
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Feature (singular, then plural form)
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Description
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Abbreviation
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Albedo Feature
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Albedo means the fraction of the light that is
reflected. An albedo feature would be color on the surface (but not a height
variation).
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AL
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Astrum, astra
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Radial-patterned features on Venus
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AS
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Catena, catenae
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Chain of craters
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CA
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Cavus, cavi
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Hollows, irregular steep-sided depressions
usually in arrays or clusters
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CB
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Chaos
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Distinctive area of broken terrain
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CH
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Chasma, chasmata
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A deep, elongated, steep-sided depression (think chasm)
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CM
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Colles
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Small hills or knobs
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CO
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Corona, coronae
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Ovoid-shaped
(oval or ellipsoidal) feature
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CR
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Crater, craters
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A circular depression , possibly with a raised
edge
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AA
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Dorsum, dorsa
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Ridge
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DO
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Eruptive center
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Active volcanic centers on Io , Jupiter’s moon
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ER
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Facula, faculae
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Bright spot
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FA
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Farrum, farra
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Pancake-like structure, or a row of such
structure
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FR
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Flexus, flex\-us
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A very low curvilinear ridge with a scalloped
pattern
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FE
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Fluctus, fluct\-us
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Flow terrain
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FL
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Fossa, fossae
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Long, narrow, shallow depression
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FO
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Labes, lab\-es
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Landslide
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LA
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Labyrinthus, labyrinthi
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Complex of intersecting valleys
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LB
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Lacus(1)
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"Lake";
small plain (not necessarily a lake with water)
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LC
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Landing site name
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Lunar features at or near Apollo landing sites
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LF
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Large ringed feature
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Cryptic ringed features
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LG
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Lenticula, lenticulae
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Small dark spots on Europa
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LE
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Linea, lineae
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A dark or bright elongate marking, may be
scalloped pattern
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LI
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Macula, maculae
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Dark spot, may be irregular
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MA
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Mare(1), maria
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"Sea"; large circular plain (none known with water)
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ME
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Mensa, mensae
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A flat-topped prominence with cliff-like edges
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MN
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Mons, montes
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Mountain
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MO
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Oceanus(1)
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A very large dark area on the moon
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OC
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Palus(1), paludes
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"Swamp"; small plain
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PA
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Patera, paterae
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An irregular crater, or a complex one with
scalloped edges
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PE
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Planitia, planitiae
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Low plain
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PL
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Planum, plana
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Plateau or high plain
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PM
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Plume
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PU
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Promontorium(1), promontoria
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"Cape"; headland
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PR
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Regio, regiones
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A large area marked by reflectivity or color distinctions
from adjacent areas, or a broad geographic region
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RE
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Reticulum, reticula
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reticular (netlike) pattern on Venus
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RT
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Rima, rimae(1)
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Fissure
(crack or narrow valley)
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RI
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Rupes, rup\-es
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Scarp
(cliff, but larger and long)
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RU
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Scopulus, scopuli
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Lobate or
irregular scarp
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SC
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Sinus
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"Bay"; small plain
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SI
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Sulcus, sulci
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Subparallel furrows and ridges
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SU
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Terra, terrae
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Extensive land mass
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TA
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Tessera, tesserae
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Tile-like, polygonal terrain
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TE
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Tholus, tholi
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Small domical mountain or hill
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TH
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Undae
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Dunes
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UN
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Vallis, valles
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Valley
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VA
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Vastitas, vastitates
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Extensive plain
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VS
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(1)
(1) Used
only on the Moon
This nomenclature write up
is basically from
http://wwwflag.wr.usgs.gov/USGSFlag/Space/nomen/nomen.html
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
