The following document contains two suggestions for team activities
for the Japan 2001 Workshop. Eric Albone requested the suggestions
at the conclusion of his visit to Cleveland, Ohio, on April
12, 2001. He then shared the suggestions with his colleagues
at Bristol University for a decision on their inclusion in the
Workshop. The first suggestion was the basis of the Space Science
Team activity.
Project 1-Draft 1
Martian Volcanoes
Objective: Draw conclusions on the structure, history, and origin
of the Martian volcanoes in Tarsus by comparing NASA photographs
of the Martian volcanoes with terrestrial volcanoes.
The group of six students may either break into teams of two
or three people, each choosing specific aspects of Tarsus to
study, or they may choose one topic and all six work as a team.
Essential to the experience is:
· Using NASA materials obtained via the www (e.g., Viking
and MGS orbital photos, etc.);
· Engaging in group dialogue, including free discussion
and brainstorming about ideas and possible theories;
· Collaborating with experts present at Bristol University
and NASA;
· Drawing conclusions; and
· Making a final presentation.
If opposing theories arise, the theories should each be developed
and presented with supporting strengths and weaknesses. The
students will thus get a taste of comparative planetology as
practiced by NASA scientists in collaboration with professionals
from different walks of life.
Project 2-Draft 1
Martian Dust Charging
Objective: Using terrestrial analogs (e.g., thunderstorms),
develop a research program for a future robotic flyer to Mars
to study electrical phenomena in depth.
There is evidence that:
· Martian surface dust acquires an electrical charge
by friction (e.g., compaction by an astronaut's boot or by a
rover wheel) or by collision (as in a dust storm, wherein airborne
dust grains collide with one another in atmospheric suspension).
· The dust acquires an electrical charge whose SIGN depends
on particle size. ('Small' particles tend to charge positively;
'large' particles tend to charge negatively.)
In order to answer the question regarding environmental electricity
on Mars, scientists will study and discuss:
· The kinds and varieties of electrical phenomena that
might occur (with supporting arguments), and
· The means of detection of each (e.g., broadband radio
to detect static noise from dust devils, etc.).
Essential to the experience is:
· Engaging in group dialogue, including free discussion
and brainstorming about ideas and possible theories;
· Collaborating with experts present at Bristol University
and NASA;
· Drawing conclusions; and
· Making a final presentation.
If opposing theories arise, or alternative detection strategies
are developed, they should each be presented with supporting
strengths and weaknesses. The students will thus get a taste
of comparative planetology and instrument design and selection
as practiced by NASA scientists in collaboration with professionals
from different walks of life.
Online Resource
Suggestions
The following list of URLs was furnished to Carsten Riedel,
EU-RTN Volcano Hazard Mitigation, University of Bristol, Bristol,
England, upon his request for (1) suggestions about where it
will be possible to find the Tarsus volcanoes in the large NASA
dataset and (2) satellite pictures from similar earth volcanoes.
Suggested URLs (Links open in new window) for images of the
Tarsus volcanoes on Mars:
The following message was sent to Carsten Riedel following
a telephone conversation in which Joe Kolecki and Carsten exchanged
a number of ideas on form and content of the Space Science team
session:
Hi, again, Carsten,
An afterthought: I am more interested in the students thinking
through issues that THEY see associated with the Tharsis volcanoes
and FORMULATING THEIR OWN SETS OF QUESTIONS AND APPROACHES TO
OBTAINING ANSWERS than I am in transferring information to them
about why we think thus and so about the Tharsis features. Science--especially
this type of science--works in a vast unknown, and the development
of good questions is often the activity of paramount importance.
Good questions usually contain the seeds of their own answers,
or of the means of obtaining those answers.
For this activity, I consider answers as being strictly secondary.
I consider the process of thinking things through and using
available resources (i.e., a good comparative knowledge of Earth)
as the single most important activity for the three days that
they will be with us. I am most interested in the process and
approach that THEY develop to thinking through the fact that
these enormous and striking features exist on a sister world
that travels in tandem with us around the sun.
Joe
Initial Groundwork
The following is a message written by Joe Kolecki. The remarks
are offered to help establish some initial ground for the week
together:
Science is the business of observing natural phenomena and
developing questions which are then answered by further consultation
with nature via experiments, and so on, and so on, and so on….
The road followed is fascinating and, apparently, without end.
The process of formulating a 'good' question is by no means
trivial, as I will try to show in the paragraphs below. A good
question is a question grounded in the best knowledge we have
in any given area. The open questions of Philosophy are usually
not admissible by this criterion.
I hope to demonstrate further by example. I am going to pursue
a chain of thought that fascinates me. Along the way, I will
draw on what I know and allow new questions to emerge. Embedded
in this process are potential seeds for future missions to Mars…provided,
of course, that my ideas hold up under the strict scrutiny of
my peers.
I've always been fascinated by the idea that the
Hellas Basin, the Tharsis volcanoes, and the Mariner's Valley
are connected by a single impact event that occurred in Mars'
distant past. Does this idea have any real merit?
Let's begin by considering the fact that Tharsis
and Hellas are not exactly antipodal (i.e., diametrically opposite).
This relationship is interesting from the standpoint of earthquake
wave propagation. Earthquakes, as you know, produce waves that
propagate outward from a highly localized area called an epicenter.
Some waves travel along the surface (P and S waves), dissipating
their energy in various kinds of surface shakes and shimmies;
others travel through earth's deep interior, eventually emerging
on the other side of the planet. The various arrivals and re-arrivals
of these waves due to reflections, etc., are responsible for
the aftershocks we hear about so often in the news.
The interior waves are DIFFRACTED by the earth's complex semi-molten
core. Diametrically opposite any given epicenter, therefore,
there exists a "shadow zone" (quiescent zone) throughout
which no interior waves arrive. (On Earth, this zone is actually
quite extensive in terms of geographical area covered.) The
occurrence and character of the shadow zones provide geologists
with important information on the structure of Earth's deep
interior.
Hellas' and Tharsis' "almost, but not quite, diametrically
opposite" relationship becomes very suggestive here. Let
us, therefore, ASSUME that a massive impactor struck Mars at
the Hellas site (essentially providing an epicenter for an absolutely
immense quake event). Let us also ASSUME a molten core on Mars
at the time of this event. What might we expect to have ensued?
MOLTEN CORE…
Mars-quake waves would be almost a certainty. Let's ignore the
surface waves for the moment and focus on the deep interior
waves. These waves would have been diffracted in a manner completely
analogous with interior waves on Earth. If these waves were,
somehow, responsible for the Tharsis and Mariner's features,
then core diffraction would account for geometry. [The students
should try to learn more about interior wave propagation at
this point.]
In order for these waves to have been responsible for Tharsis,
et al., they would have to have carried enough energy from Hellas
to Tharsis through Mars to produce the bulge, the volcanoes,
and the Mariner's Valley.
[Let's digress for a moment. For visualization: The Mariner's
Valley is over 2,000 miles long and 3 miles deep at its greatest
depth. It is very much like the split in the skin of a baseball
that has been overstressed. (What would happen to a baseball
that was hit sharply with a heavy object?) The crust of a terrestrial
planet is very like the skin of a baseball, in scale, when compared
to the overall bulk of the planet. Thus, the Mariner's Valley
may be viewed as a titanic rift or split in the Martian crust.]
IMPACTOR…
Let's think some more about energy. I have included a calculation
that estimates the energy, mass, etc., of the Hellas impactor.
Please note that the calculation shows that, in order to produce
an impact feature the size of Hellas, the impactor would have
to have had a mass one trillion times larger than the largest
impactor known today on Earth. The energy would be correspondingly
larger also! We will return to this point later….
BACK TO THE MOLTEN CORE…
First, though, let's return to the idea of a molten core. Although
it is pretty well established that today Mars has a solid metallic
core, our ideas on planetary formation lead us to believe that,
almost certainly, Mars had a molten core at some point in its
history. This notion will help us to establish a time frame
for our hypothetical Hellas event.
Now, because Mars is 1/2 the [linear] size of Earth, we might
guess (just for the purposes of roughing out ideas) that it
had 1/8 the initial interior heat of Earth and that it cooled
at roughly twice the rate.
[N.B.: This is a thumbnail-type calculation: 1/2 the size ->
1/4 the area and 1/8 the volume. Heat is stored in the volume
and lost through the surface. ASSUMING equal initial thermal
energy densities for Mars and Earth leads to the idea of 1/8
the initial thermal energy. And, since the surface-to-volume
ratio of Mars is twice what it is for Earth, Mars would have
cooled - initially, at least - at roughly twice the rate.]
Mars would have grown cold much more quickly than Earth. This
idea tallies nicely with conditions observed on Mars today.
We observe that the planet is now in a protracted ice age. That
Mars was warmer in its past, and possibly more earthlike, is
evidenced by numerous arroyos and alluvial features seen from
orbit. It is probable that Mars had a more extensive atmosphere
in its past than it does now and that much of this atmosphere
was lost due to Mars' lower escape velocity (Mars has 1/3 the
surface gravity of Earth). This loss, combined with the other
factors we have been discussing, would have lead to an overall
cooling down of the planet during its early epochs.
So…IF Hellas and Tharsis are connected, then these features
MUST be very ancient; in fact, the forming event must have occurred
during the earliest initial epochs of Mars' existence. Does
THIS idea make sense?
Well, we know that Hellas' overall features are softened by
erosion due to tenuous Martian winds, and that the entire region
is pockmarked with more recent impact features. We also know
that the Tharsis volcanoes have impact features, though not
as many as Hellas (as would be expected if these volcanoes were
active for long periods of time)… And so on. The students
might want to pursue these ideas further…
NOW, BACK TO THE IMPACTOR…
Returning to the enclosed calculation: The Hellas impactor is
estimated to have been immense by any standard of comparison
known today on Earth. Could such an impactor really have existed
in the early solar system?
We know (from the occurrence of craters throughout the solar
system) that solid debris were ubiquitous and that, in fact,
there WERE some pretty big objects moving in orbit about the
sun during the late phases of the early solar system (when Mars
was still warmer and more earth like). Additionally, Mars has,
as one of its neighbors, the asteroid belt (which was also likely
formed or forming during this early period). The asteroid belt
is thought to consist of the remains of a terrestrial type planet
broken apart by tidal stresses induced by Jupiter's gravitational
field. So not only were large objects available, but if the
pre-asteroidal planet (planetoid?) really had a structure similar
to the inner planets, iron or iron-nickel fragments would [should]
have been available from the core…
ETC. …
And so on. Again, the students might want to pursue these ideas
further, or develop new chains of thought of their own. They
must remember that speculation must be bracketed as much as
possible by our present (though admittedly incomplete) knowledge
of reality. We draw on what we know to try to push forward into
new realms.
Looking forward to a great week together!
Ciao!!!
Joe Kolecki
E = 4 x 1013 d3 erg = 4 x 106
d3 j (d in meters)
Also: (Crater Mass Displaced)/(Mass Impactor) ~ 60,000
Nominal Density of Mars:
= 3.9 (H2O
= 1)
Hellas Basin:
d = 2,300 km = 2.3 x 106m
Calculations:
1. Energy of the impactor:
E = 4.9 x 1025 j
2. Mass of Impactor:
Assume entry speed v = escape velocity from sun @ Mars orbit
radius
v = 4.1 x 104 m/s
Set E = K.E. and determine mass
4.9 x 1025 j = ½ mv2
m = 5.8 x 1016 kg
[Compare: Mass of greatest known impactor on Earth: 8 x 104
kg]
3. Mass M of ejecta:
M = 60,000 x (5.8 x 1016 kg) = 3.5 x 1021 kg
3a.) Speculate about crater depth h:
Assume a cylindrical crater. Then:
Crater Volume = r2h
= (3.5 x 1021 kg)/(3,900 kg/m3) = 9.0
x 1017 m3
And, with r = 1.2 x 106 m, we find that h = 2.0
x 105 m or about 200 km.
[Actually, this depth is close to 10% of the crater diameter,
which matches measured results for terrestrial and lunar craters
fairly nicely.]
4. Size of impactor:
Assume spherical impactor and find its radius s
5.8 x 1016 kg = (4/3) s3
(8,000 kg/m3)
s = 12 km
Reference:
C. W. Allen, Astrophysical Quantities, 2nd Edition, U. of London,
1963, pg. 139-140.
J. R. Percy (ed.), Observer's Handbook, 1977, Royal Astronomical
Society of Canada, pg. 6, 8.
Joe Kolecki
message
The following is a message written by Joe Kolecki to Lawrence
Williams before the event:
I am looking forward to the upcoming week with you and the students.
There is SO much to tell them, and SO little time! I hope to
convey to them the tentative nature of modern science (all science!)
and to convince them of the importance of carefully investigating
and developing good questions. I once read a commentary that
a well formed question contained within itself the seeds of
its own answer. Over my 32 years at NASA, I have come to embrace
this idea as foundational in my work. After all, we build our
spacecraft, wind tunnels, etc., all based on the logic invested
in the questions we wish to answer!
Along the same lines: I spoke, a couple of years ago, with
a group of exo-biologists who were developing life sciences
experiments for Mars. I asked them what sorts of "things"
they were looking for on Mars. They answered that they had not
the slightest idea. "All we understand is terrestrial biology,"
one of them explained. "So, we are using terrestrial biology
as our starting point. We do not necessarily expect to find
terrestrial forms, but we hope to garner enough clues from this
initial step to formulate more accurate second generation life-sciences
experiments."
This experience is one of the most telling cases in point I
have ever come across regarding the type of philosophy I hope
to share with your students. If they learn some new ways of
thinking about their world in the few days that we are together,
then they will have achieved more than all the "right answers"
in the world put together!
And, who knows…someone may just uncover a line of reasoning
that is genuinely new. Then…just think of the possibilities!!!
Carsten Riedel
message
The following message was written by Carsten Riedel to Ruth
Petersen and Joe Kolecki on July 17, 2001:
I am quite fascinated by the ideas in "Hellas Impactor"
mail. However, I would propose to launch the project by a more
superficial approach, before we actually get to those points
in the actual Wednesday session, which is the longest. My idea
is still to start off by looking at the Tharsis volcanoes, slopes,
flows and cones and get them starting to worry about what volcanoes
these may be. And then we slowly work our way from surface to
interior by thinking of the differences between Tharsis volcanoes
and Hawaiian volcanoes, such as, what restricts the size of
the Hawaiian volcanoes? The answers could be very diverse such
as:
1. Gravitational sliding--why could there be more gravitational
sliding on Earth than on Mars?
2. Crustal thickness and so on…
3. Composition of lavas
4. Hawaiian volcanoes get more and more silicic, i.e. explosive,
so what they built up is destroyed again. Could that happen
on Mars as well? Why or why not?
5. Effect of the moving plate, all is built on one spot, i.e.,
monogenetic volcanoes on Mars.
That will get them thinking about the deeper origin of things.
We are also going to show them how basic features on the photos
- like flows or cinder cones - can be modeled in the lab very
easily. So that they get an understanding of what static photos
can actually tell about the dynamics of a process…
As far as I understand there is not much time before the first
videoconferencing session, so until then they will get a basic
introduction to volcanoes by Steve Sparks and we will try to
inspire a discussion which will tell us how much they already
know by showing them some of the Mars pictures and comparing
them to Japanese volcanoes first and Hawaiian volcanoes afterwards…
So that is the plan. The first videoconferencing session is
thus more or less an introduction of our group - i.e., Stuart
and me - and you at NASA and the students to each other.
The following message was written by Joe Kolecki in answer to
Carsten's July 17 message:
Your approach makes complete sense. I would add to it the building
of scale models. For example, Mt. Olympus is, nominally, 180
km in base diameter and 10 km vertically from base to summit.
This set of numbers, taken alone, could be compared with dimensions
of the largest mountains on Earth. I enjoy using Mt. Everest,
3.3 km from base to summit.
Further: The calderas of Mt. Olympus have scale sizes of around
30-50 km or so. And the vertical escarpments around the base
measure something like a 1.5+ km (variable with location). By
simply drawing a cross section of the mountain, one gets an
immediate impression of flatness (which is surprising at first
glance!). A similar exercise could [should] be done with Hellas
(2300 km diameter by nominally 200 km depth).
Going on, again: The nominal vertical extent of the Martian
"lower" atmosphere is 0 - 45 km, and of the "middle"
atmosphere, 45 km - 110 km (ref., Kieffer, et. al., "Mars,"
pg., 810, 811). Thus, the summit of Mt. Olympus is, essentially,
in outer space. This fact should strongly influence how the
students think about Mars. There is no direct analogy to such
a system on Earth.
Finally, if a scale drawing of Mt. Olympus were turned upside
down and placed into the scale drawing of Hellas (assume a cone-shaped
basin here for simplicity), the immense Mt. Olympus would suddenly
become a dwarf compared to the even more colossal H. Basin.
One might ask how such a "small" planet could acquire
such enormous features.
Anyway, these are all just suggestions. When we video conference,
I hope not so much to lecture as to elicit questions. By doing
so, I hope to attempt to address those concerns that are closest
to the students hearts and minds without throwing a lot of extra
confusing detail. I will rely on you and your colleagues to
guide things along on that end and to jump in at any point during
my comments as you see fit.
The following quotation from the patron of the Workshop was
sent to Joe Kolecki by Lawrence Williams:
"The more we can build international links among young
people, particularly in the field of science which is itself
entirely international in its impact, the better it will be
for the future of the human race and the world we inhabit."
(Rt Hon the Lord Jenkin of Roding, Workshop Patron, welcoming
the students to the Japan 2001 Workshop.)
The following message was sent to Lawrence Williams from Joe
Kolecki in response to Lord Jenkin's quotation:
Yes, I agree with the enclosed quotation. I am currently reading
Jules Verne's "Master of the World," which depicts
a period in history when the lone scientist/inventor was a believable
and viable entity. With the advent of 20th century science,
this lone figure recedes, to be replaced by teams of specialists,
each an expert in some part of a field or project whose full
content is too large for any one individual to master. The launch
of Apollo and the subsequent development of the Space Program
bring into existence even larger groups. A successful launch
requires the intricate cooperation of several hundred or more
people, each with a specific set of tasks that must integrate
with precision.
The further exploration of our Earth, and the extension of that
activity into the solar system (and beyond), will be/become
a global undertaking. We now know that the earth is not to be
studied as a set of separate systems or subsystems operating
semi-independently together. The earth is a single, tightly
integrated system, a network, if you please, whose connecting
links represent complex information pathways, and whose nodes
represent individual states which are, themselves, complex sub-networks
connected to the whole. The same must apply to the solar system
as a whole, and to its individual planets, moons, etc., as well.
International cooperation brings into play resources - people
and systems - whose whole is certainly greater than the sum
of its parts. Such cooperation is the most viable path into
the future, if it can be achieved and maintained peacefully
and with a strong bond of mutual trust.
I hope you will forgive this long but necessary collective
email to you as people who have all so very kindly given of
your time in leading the various Project Teams of the Workshop.
It really is on track to be an excellent event, and we do thank
you.
The students will be arriving on Sunday afternoon 22 July and
they will be staying at Churchill Hall, as will a number of
the organisers. I attach a complete listing of the students
and the schools they are coming from to give a sense of breadth
of what we are attempting.
1) INTRODUCTORY MATERIALS: Before they arrive in Bristol, it
would be immensely helpful for the students to have an introductory
sheet about the objectives of their Project Team (in some cases
with other material), getting them to think about it in advance.
Quite a number of Project Teams have done this quite recently
and it is appreciated... we are already in touch with quite
a number of the students by email and I know how thrilled they
are about the week... and in some cases a little apprehensive.
If you are leading a Project Teams whihc has not yet done this,
could I say that putting together such a sheet, written in a
chatty but informative style, would be immensely helpful; it
need only be quite brief. To give an idea what others have done,
I have attached (and I hope without causing embarrassment) two
examples of such the introductory sheets from the Environment
Team Project and the Science through Theatre Team Projects.
These have already gone out to the students.When you have a
draft, just email it to me and I will deal with the rest.
2) INTRODUCTORY SESSION: The first session on the Monday morning
(23 July at 9.15) in the Mott Lecture Theatre of Bristol University
Physics Department will involve all the students. It will be
in two parts. Before coffee there will be some words of welcome,
encouragement and inspiration from a number of people including
Prof Steve Sparks (who is leading the vulcanology project team
and will also represent the Royal Society), Prof Gordon Stirrat
(from the Institute of Advanced Studies) and Prof Haruo Hosoya
and Prof Mamoru Shimoi (representing the Japanese scientific
societies who have collaborated so enthusiastically in recruiting
the Japanese students). Valerie Davey, MP from Bristol West
and Member of the
Commons Education Select Committee will also be with us.
After coffee, will be the time to give the students as a group
overall
orientation and introduction to the Workshop, to answer their
questions and to link them with their Team leaders. It would
be really valuable is you or one of your associates could be
with your students at that event. You would also have the chance
if you wished to speak to the whole group of the cuff for a
few minutes about what your Team will be doing... to give everyone
the broad picture.
I would value your comments, ideas and suggestions about how
to make this session work to maximum effect.
2) MEALS AND THINGS The students will be issued with vouchers
for lunches at the Hawthorns, to be taken at any time between
12.30 and 2.00. Students will be staying at the Churchill Hall
where they will have their other meals. They will come into
Bristol University by bus each morning, and be taken back by
bus in the evening; the pick up point is at the Hawthorns.
Because there are too many people (students plus adults) for
one journey,the bus will do two runs each way each day, (arriving
at approx 8.45 and 9.15 each morning and departing at 17.00
and 17.30 each evening). Of course for those Teams where the
work is not based on the main University of Bristol Campus,
it may not be necessary to come into Bristol at all.
Each team will have the service of a native Japanese speaker
who has good English (often Japanese undergraduate or graduate
of the University) It is for the Project Team Leader working
with these Facilitators to be responsible for ensuring the student
groups are given, and follow, clear instructions about where
they are to be at all times in the day.
3) STUDENT PRESENTATIONS One of the outcomes will be concise
public presentations by each Team of the essence of what they
have achieved during the week. This event will be held in the
Tyndall Lecture Theatre of Bristol University Physics Department
starting at 2.00 on the afternoon of Friday 27 July (we have
booked the room all day, so preparations can start earlier).
Because there are 10 groups (and all will be very productive)
presentations must necessarily be concise and sharp.. 10 min
+ 5 min discussion at the most I would think. To help the process
we are booking a good video projection facility from outside
the university, which will enable the Teams to give a taste
of what they have achieved efficiently and effectively though
video, if they wish; also through Powerpoint.
I would most certainly be grateful for your further comments
and
suggestions about ways of making this afternoon a really outstanding
and memorable for all concerned.
4) OTHER OUTCOMES Because the presentations will only give
a taste of what has been achieved, and because we wish the workshop
to maximise its impact, we ask each group to produce a Team
Report (in some cases this would include video material) of
its work to contribute to the full Workshop Report which we
will produce and distribute to interested people as well of
course as to the participants. The students could also take
copies of their own team reports away with them at the end of
the workshop.
Finally, we are also setting up a Workshop Website which will
provide yet another means of sharing outcomes more widely.
Apologies that this has been so long. I hope it is helpful.
= 3.9 (H2O
= 1)
m = 5.8 x 1016 kg
r2h
= (3.5 x 1021 kg)/(3,900 kg/m3) = 9.0
x 1017 m3
