button to find messages posted previously. Thank you for joining us
today, and welcome!
[ NathanBridges/JPL - 43 - 10:11:54
RE: [Stephanie/Edmonton] Did you name any
of the rocks?
Stephanie, I did name a few: Half Dome and Hippo are the ones I remember,
but there are a few others too. The names actually served a useful purpose
by helping us remember features at the landing site. They were also
very popular with the public. --Nathan
[ NathanBridges/JPL - 49 - 10:16:24
RE: [Stephanie/Edmonton] Are most of the
rocks similar to Barnacle Bill or Yogi in composition or totally different?
Mostly igneous or sedimentary?
Stephanie, The rocks have some minor compositional differences, but
in general appear to have chemistries similar to basalts and andesites.
However, we cannot be sure whether the rocks are actually igneous or
are instead sedimentary rocks, metamorphic rocks, or even impact glasses
that have compositions similar to basalts or andesites. We also are
uncertain whether the compositions we have measured represent the bulk
rocks or just the outer surface of the rocks. --Nathan
[ NathanBridges/JPL - 53 - 10:19:53
Teaching young children, we appreciated the model of persistence your
bio demonstrated. As we teach geology and the planets this year, what
big ideas should young children understand?
Renae, Good question. I think it is really important for children to
understand where they fit in the Universe. They should have a concept
that they live on a planet, that it is just one of nine planets in our
solar system, and that the sun we orbit is just one of a few hundred
billion stars in our galaxy. By giving kids a sense of that, they can
start to understand what other planets are and what our first steps
in space exploration (occuring today) represent. --Nathan
[ Oran/NASAChatHost - 54 - 10:20:42
For those of you posting questions at this time, they will not appear
on your screen until Nathan has caught up with other questions. We hope
to have your questions posted to the chat room as soon as possible.
[ NathanBridges/JPL - 55 - 10:23:51
RE: [John-JohnOlson/ArlingtonHS] What are
your latest ideas on the geologic origins of the rocks you studies?
John, We are still working on that question, but we have some ideas.
The rocks seen at the landing site probably derive from two main source:
1) Rocks deposited by the floods that flowed through the landing site
area about 1.2 billion years ago, 2) Rocks ejected during impact events
that formed craters. The composition of the rocks are similar to basalts
and andesites on Earth, but we cannot be sure that all of the rocks
are igneous. Some appear to have a layered texture and may be sedimentary.
Many rocks have also been modified by the wind, exhibiting flutes and
other features. --Nathan
[ NathanBridges/JPL - 56 - 10:27:08
RE: [Manfred-Gymnasium] My question: Can
it be that the vulcanic stones "B.Bill, Yogi,..... come from the vulcans
from the Tharsis-region,because Ares Vallis is a region with no vulcanic
activities now and long time ago?
Manfred, The Tharis volcanoes that you mentioned are probably too far
away from the Pathfinder landing site to have contributed any rocks
to the population that we see. Any volcanic rocks probably represent
1) samples of nearby small volcanoes or 2) Samples of lava flows that
makeup the bedrock of Mars and that were later removed by the floods
or impact events. --Nathan
[ NathanBridges/JPL - 58 - 10:32:02 ]
RE: [Alexandre/MacaBrasil-Mrs.Alexandre/LenepUenf] Mr Nathan
Bridges As we know, the Martian atmosphere is basically carbon dioxide
and other gases, being completely different from earth atmosphere. This
way about Martian's atmosphere what is the main influence of this different
composition in the geologic cycle which produces in our planet the several
kinds of rocks?
Alexandre, Mars' atmosphere is predominantly carbon dioxide, as is that
of Venus. Our atmosphere would probably have a similar composition were
in not for two main factors. One is that we have large bodies of water
that absorb carbon dioxide, which is commonly converted to limestone
and other carbon-rich rocks. The other reason is that plants on Earth
absorb carbon dioxide and convert it to oxygen. --Nathan
[ NathanBridges/JPL - 62 - 10:36:16
RE: [Pedro] Nathan, I'm on the last
years of geology, I like to know if is better make a master in image
interpretation or are something moor spesific. (sory for my english)
Pedro, If you want to be a geologist who studies Earth and other planets,
it is probably best to pursue traditional geologic studies. Experience
looking at real rocks in real environments is some of the best education
that you can get. Of course, if you are really interested in image analysis,
by all means go for it. --Nathan
[ NathanBridges/JPL - 63 - 10:39:03
RE: [Illian] Hi Nathan. I am a programmer
and I also have masters degree in electronics. I was wondering what
computers do you use there in JPL ? And what operating system ? And
can you tell me something more about the Pathfinder's software ? I suppose
it is programmed in Assembler, but what is the processor? Thank you
very much !
Illian, For basic stuff, we use PCs and Macs. For image analysis and
engineering software (such as communicating with the spacecraft, when
it was operational) we use Suns and SGIs. We use the Unix operating
[ NathanBridges/JPL - 64 - 10:39:48
RE: [Stephanie/Edmonton] Do you recommend
taking biology in high school if one plans to take engineering and geology?
Stephanie, Yes. It is very good to have a broad education. --Nathan
[ NathanBridges/JPL - 66 - 10:41:33 ]
RE: [Cherie/AllianceMS-Cherie/AllianceforMS] We were wondering
if there is a connection between the red rocks of Mars and its geology
and the red rock park in Colorado.
Cherie, There is not exactly a "connection," but the redness on Mars
and the red rocks in Colorado are both due to oxidized iron. --Nathan
[ NathanBridges/JPL - 69 - 10:43:22
RE: [JohnWyoming-pack70/scouts] I also love
astronomy and read and study everything I can find. Can you suggest
any good books for school age kids.
Hi John, The New Solar System and The Cambridge Atlas of Astronomy are
quite good. --Nathan
[ NathanBridges/JPL - 70 - 10:47:26
RE: [stephan-mrs.c/home] do you thiink you'll
find eggs water or microbes in the rocks?
Stephan, --I really doubt that eggs will be found in any rocks from
Mars. Save for a few fossils, such a find is rare even on Earth. Microbes
in Martian rocks is also pretty unlikely; I am one of the scientists
who is skeptical that microbes were discovered in that Martian meteorite
two years ago. However, minor amounts of water have been found in Martian
meteorites and it is likely that water bound in the rocks will be found
on the planet. Mars also contains frozen water in the polar caps and
water vapor in the atmosphere. --Nathan
[ NathanBridges/JPL - 71 - 10:49:23
RE: [Alexandre/MacaBrasil] Is there
any evidence about tectonic plates in the Martian litosphere similar
we have on the earth?
Alexandre, There really is not much evidence for this. Limited amounts
of extension and compresion have occurred (as evidenced by rifts/graben
and wrinkle ridges, respectively), but there does not appear to be an
integrated plate tectonic system like on Earth. --Nathan
[ NathanBridges/JPL - 74 - 10:50:44
RE: [Stephanie/Edmonton] Was it difficult
to learn how to write sequences know your background is in geology.
Stephanie, Sort of. I worked many hours, some times late at night to
do this. I had some computer experience prior to working at JPL, so
that helped. --Nathan
[ NathanBridges/JPL - 75 - 10:52:51
RE: [Megan] How thick is Mars' crust?
Megan, This is not known too well. It is probably on the order of 100
km or so. What is needed is some seismic profiling of Mars' interior
to address this question. --Nathan
[ NathanBridges/JPL - 78 - 10:55:28
RE: [Pedro] Were I can learn about
the interior of mars?
Pedro, Some of the latest results are reported in the 12/5/97 and 3/13/98
issues of Science magazine. Also see chapters in the book Mars, edited
by Kieffer, Jakosky, Snyder, and Matthews. --Nathan
[ NathanBridges/JPL - 79 - 10:58:31
RE: [sarah] how can we get info in
the mail about all this stuff? how do you think i fit into all this
Sarah, Contact the JPL public affairs office: JPL, MS 186-301, 4800
Oak Grove Dr., Pasadena, CA 91109. You fit in by being interested and
expressing that interest to NASA and JPL. Being funded by taxpayers,
it is our roll to make sure that all of the exciting things we find
get relayed to the people. --Nathan
[ NathanBridges/JPL - 82 - 11:00:33
RE: [Alexandre/MacaBrasil] Considering
the future space flight to Mars, Is there any magnetic and gravity survey
programmed to this planet ?
Alexandre, The current spacecraft in orbit around Mars, the Mars Global
Surveyor, has a magnetometer. It has already found evidence for an ancient
magnetic field around Mars. All spacecraft in orbit around Mars are
tracked, which yields data on gravity. --Nathan
[ NathanBridges/JPL - 83 - 11:02:43
RE: [Stephanie/Edmonton] Is there
an explanation for why Yogi is two-toned?
Stephanie, Originally we thought this was due to dust covering part
of Yogi. However, we later found that the boundary between the red and
gray parts of Yogi changes with the time of day. The explanation is
that red dust in Mars' atmosphere scatters light, so that all areas
that are not directly illuminated are instead lit by diffusely-scattered
red light. --Nathan
[ NathanBridges/JPL - 86 - 11:04:23
RE: [Rebecca] I read this morning
in the news paper about the McKay team's findings of Allen Hills 84001.
Quoted in the paper was "So far, no one has found absolute, incontrovertible
evidence that the potato-sized chunk ever contained life." What is your
opinion about that?
Rebecca, I am on the side of most scientists in thinking that positive
evidence for life has not been found in that meteorite. It certainly
would be exiciting to find evidence for life on Mars, but to do that,
we will probably have to wait until we can go there ourselves. --Nathan
[ NathanBridges/JPL - 87 - 11:06:37
RE: [Stephanie/Edmonton] Did you have
the chance to put your name on the picture of Ares Vallis in the hallway
of mission control to guess the landing site of Pathfinder?
Stephanie, Yes I did and lost $1. We had a voluntary betting pool in
which people on the project guessed where the landing site would be.
My collegue Justin Maki won and collected about $70 (I think). I did
come close though. --Nathan
[ NathanBridges/JPL - 88 - 11:08:25
RE: [Stephanie/Edmonton] Is there
anything that you can study that's between planetary geology and astronomy?
Stephanie, Planetary astonomy is probably what you want. People who
study that look at Solar System objects through telescopes. --Nathan
[ NathanBridges/JPL - 89 - 11:10:19
RE: [Manfred] I've heard that the
meteroits from Mars are much different than the marsstones examined
by Sojourner, is that correct? In which way are they different?
Manfred, They are different. The meteorites are very rich in iron and
relatively low in silica. The rocks examined by Sojourner appear to
be somewhat rich in silica and have low iron contents relative to the
[ Oran/NASAChatHost - 90 - 11:10:30
EVERYONE, we will be ending our chat with Nathan Bridges shortly. The
chat room will remain open for Nathan to answer questions waiting to
be answered. However, NO NEW questions will be accepted for the chat
room. Thank you very much for your patience today, and for joining us
for our chat with Nathan Bridges.
[ NathanBridges/JPL - 94 - 11:13:11
RE: [Illian] Nathan, it's Illian again.
Can you tell me something more about the Pathfinder's hardware and software
or it is strictly confidential ? :-)
Illian, No it is not confidential. To really get as much info as possible,
check out the URL http://mpfwww.jpl.nasa.gov/default.html.
[ NathanBridges/JPL - 96 - 11:14:29
RE: [JohnWyoming] Have you written
any books or articles that I could find at the library or on the Internet?
John, I have not written any books. Articles I have written have been
in scientific journals such as the Journal of Geophysical Research,
Science, and Geophysical Research Letters. --Nathan
[ NathanBridges/JPL - 97 - 11:16:47
RE: [Rebecca] What is your opinion
on the so-called "faces on mars"? Please make your answer somewhat simple,
I am only 15.
Rebecca, The putative "faces" are natural features, just as clouds in
the sky that look like Elvis are natural. Unfortunately, some people
have made the case that NASA is covering up information and that the
face was made by intelligent Martian beings. That makes a good episode
of the X-Files, but it is not true.--Nathan
[ NathanBridges/JPL - 101 - 11:18:53
RE: [Stephanie/Edmonton] What have
you learned from the Material Adherence Experiment?
Stephanie, I am not involved with that experiment. However, I think
they have documented a steady increase in dust deposition over time
on the Martian surface. This makes sense. In pictures of the Pathfinder
landing site you can see that flat rock faces are covered with red dust.--Nathan
[ NathanBridges/JPL - 102 - 11:19:57
RE: [sarah] do you think we well ever
live on another planet?
Sarah, Yes I do. It is just a matter of time. People have already been
to the Moon and two people live in space now (on Mir), after all. --Nathan
[ NathanBridges/JPL - 103 - 11:21:15
RE: [Cherie/AllianceMS] Nathan, Do
you know of any software connections that we can use with 3-8th grades?
Do you know of any teacher-friendly sites that we can use to educate
ourselves of the current research?
Cherie, Check out the Pathfinder web site:
http://mpfwww.jpl.nasa.gov/default.html. There should be some good
information there. --Nathan
[Illian - 107 - 11:23:05]WOW, someone is using the metric system
in the US !!! :-)))
[ NathanBridges/JPL - 108 - 11:23:12
RE: [Alexandre/MacaBrasil] Mr Nathan
Nowadays I'm studying the clay influence in the conductivity of rocks
in the earth conditions. It is very interesting the polarization process
observed in this condition when alternating electrical fields is applyed.
My planning for the future is to study electrical parameters of rocks
from other planets. Do you know any book related to this matter ?
Alexandre, That is a very specific topic and I am not aware of any books.
Some studies of the electrical properties of rocks have been done for
application to radar studies. So, you might comb the radar literature.
[ NathanBridges/JPL - 109 - 11:24:22
RE: [Stephanie/Edmonton] Should we
Stephanie, Maybe parts of it, perhaps under domes or something. I would
kind of feel bad if we totally wiped out the old planet for our uses.
[ Cherie/AllianceMS - 110 - 11:25:30 ]
Thank you so much for your time and patience. This was very exciting
for us...15 in all. Our students will greatly benefit from this way
of comunicating with the real people of the real world.
[ NathanBridges/JPL - 111 - 11:25:51
RE: [sarah] did you ever feel like
going to something else.wondering if this was right for you?
Sarah, I really do like my job, so I would not change fields. --Nathan
[ Oran/NASAChatHost - 112 - 11:26:24
RE: [Cherie/AllianceMS] Thank you
so much for your time and patience. This was very exciting for us...15
in all. Our students will greatly benefit from this way of comunicating
with the real people of the real world.
Cherie, we're glad you could join us today, and hope you will be able
to do so again. Thank you and your students for your questions.
[ NathanBridges/JPL - 115 - 11:28:10
RE: [sarah] do you think there will
be a space program when we grow up?
Sarah, Yes, I think so. Space exploration is really taking off these
days and probably will expand in the future. --Nathan
[ sarah - 116 - 11:28:14 ]
thank you for your time ill remember for the rest of my life
[ Oran/NASAChatHost - 117 - 11:28:32
RE: [sarah] thank you for your time
ill remember for the rest of my life
Sarah, thank you for joining us today.
[ NathanBridges/JPL - 118 - 11:28:52
RE: [Manfred] Why did you take Cu
244 for the alpha emitter, it's an artificial element and probably expensive
to produce. Is it better than Uran or Radium ?
Manfred, I do not know. --Nathan
[ NathanBridges/JPL - 119 - 11:29:07]
RE:[Mr Nathan] Here on the earth
is possible to have an idea about the inner of the crust, detecting
the P and S waves priduced by earthquakes which can be detected by several
sysmic stations around the world. Using two or three stations in the
opposite side of the Mar's surface is not possible do the same in order
to discover the inner characterisitcs of Mars?
Alexandre: In principle, this is possible. There have been proposals
to put a series of seismic stations on Mars to undertake just such a
project. At the present time, these are only paper studies and there
is no committment to develop this. One problem is that Mars probably
does not have many quakes, being a relatively inactive planet that lacks
plate tectonics. Impacts and artificial explosions could be used to
generate seismic waves, however, such as was done on the Moon for seismic
stations set up during the Apollo program.
[ NathanBridges/JPL - 120 - 11:29:07]
RE:[ Stephanie/Edmonton] Are other
two-toned rocks or soil also caused by light-diffusion?
Stephanie, Yes, this is seen over the whole Martian surface. It was
particularly obvious at Yogi because it is such a large rock.
[ NathanBridges/JPL - 121 - 11:29:07]
RE:[Pedro] Were I can found geology
maps of the surface of mars? In the web or a book.
All the information you need should be at this URL:
[ NathanBridges/JPL - 122 - 11:29:07]
RE:[ Manfred] Dit the APXS discover
No, organic molecules were not detected during the Mars Pathfinder mission.
[ NathanBridges/JPL - 124 - 11:32:40]
RE:[Illian] Nathan, it was nice talking
to you. Is there any one from JPL who I can e-mail to and get more info
on Pathfinder's embedded software? Because I checked the web site you
gave me but I couldn't find anything more specific. Thank you. Have
a nice day!
You might try David Gruel at NASA JPL (contact Oran/NASAChatHost at
firstname.lastname@example.org for David's contact
information). He was one of our main software gurus.
[ Oran/NASAChatHost - 123 - 11:32:31
Everyone, Nathan must log off for now. Thank you to everyone for joining
us for today's chat with Nathan Bridges from NASA Jet Propulsion Laboratory
in Pasadena, CA. We would like to send a special thanks to Nathan for
chatting with us today, and for staying with us for an additional 30
[ Oran/NASAChatHost - 125 - 11:33:48
For upcoming chats with NASA experts, check the Quest schedule of events
page, at http://quest.arc.nasa.gov/common/events/index.html.
[ sarah - 126 - 11:33:57 ]
thank you.have a good day
[ Alexandre/MacaBrasil - 130 - 11:42:39 ]
Mr Nathan Thank you very much for this time chating with us Alexandre
[ Manfred - 131 - 11:42:39 ]
Thank you to Oran/NAsachat-host to make such events possible.There should
be more such events, for young people, who want to become scientists.
You all and Mr. Bridges did and do a great job.!!!!!!!!!!!!!!!!!!!!!!