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Mars Team Online QuestChat

Date: August 5, 1998

Featuring: Nathan Bridges
Planetary Geologist
Jet Propulsion Laboratory, Pasadena, CA

Main Room

last read Wed August 10:00:09 1998

[ Oran/NASAChatHost - 9 - 09:47:32 ]
At the conclusion of this chat, you will have the opportunity to let us know what you thought about it. You can share your thoughts with us by taking a few minutes to respond to some questions, located at http://quest.arc.nasa.gov/qchats/qchat-surveys/index.html. We strongly encourage you to provide feedback to us. Your comments will help us with future chats. Thanks in advance for your help.

[ Oran/NASAChatHost - 11 - 09:48:22 ]
RE: [Stephanie/Edmonton] Good morning Oran!
Good morning, Stephanie. Welcome back. We'll begin our chat shortly. Thanks for joining us today!

[ Oran/NASAChatHost - 13 - 09:50:55 ]
RE: [Stephanie/Edmonton] How's it there at Ames?
Well, I'm happy to say that the weather is finally beginning to cool down a bit, after a few days of 100+ degrees F. We're hoping to get down to the low to mid-80s by the end of the week.

[ Oran/NASAChatHost - 15 - 09:54:13 ]
RE: [Stephanie/Edmonton] It's hot here too! I've been told that all the fans in the city are sold out.
I believe it, Stephanie. We've been warned that our electric companies may instigate "rolling brown outs" because of the high energy demand. But if the weather cools a little, we may be spared. Let's hope so!

[ Oran/NASAChatHost - 17 - 09:55:56 ]
RE: [Sarah/MadisonWI] Ouch! My brother lives near Palo Alto, CA, and he's been complaining about the heat too:)
Sarah, yes, many areas in the San Francisco Bay Area have felt the effect of the heat wave. I live in San Jose, and Monday and Tuesday saw degrees of 103 and 102 degrees F. Very hot!

[ Stephanie/Edmonton - 20 - 09:56:51 ]
Well, at least it doesn't get too cold down there. We'll all have to brace for La Nina.

[ Oran/NASAChatHost - 19 - 09:56:39 ]
RE: [Manfred] Hello to everyone out there !
Manfred, we're glad you could join us. Welcome! We will begin our chat with Nathan Bridges in a few minutes.

[ Renae/Vashon - 21 - 09:58:22 ]
Good Morning, We had a little trouble reaching the chat room URL. Thank you for giving us a back door.

[ Oran/NASAChatHost - 22 - 10:00:09 ]
Hello and welcome to today's Mars Team Online chat with Dr. Nathan Bridges from NASA Jet Propulsion Laboratory! Since late September, 1997, when the Mars team stopped hearing from Pathfinder, virtually all of Nathan's time has been spent analyzing the large amount of images and other data collected by the Mars rover. Nathan's primary areas of study are understanding the chemical makeup of the rocks and soil, and the effects of wind on the surface. Nathan continues to study Mars data, and will soon have results of his investigations published in a scientific journal.

[ Oran/NASAChatHost - 23 - 10:00:34 ]
And now, here is Nathan Bridges to answer your questions.

[ Oran/NASAChatHost - 30 - 10:05:56 ]
RE: [Cherie/AllianceMS-Cherie/AllianceforMS] Good afternoon from Michigan. The temperature here is high 70" and rain. We are classroom teachers looking forward to seeing how we can use a live chat with students.
Welcome, Cherie. Nathan Bridges from NASA JPL is here to answer your questions today.

[ NathanBridges/JPL - 26 - 10:03:50 ]
RE: [Cherie] Are there theories about what happened to Pathfinder and why it stopped sending data?
Hi Cherie, Yes, we think we know what happened. The battery on the lander finally ceased operating. By itself, this would not cuase a problem because the lander can run of solar power. However, the battery shutdown was unexpected and caused the clock on the spacecraft to get reset. The lander could not tell what time it was, so it did not know when to contact Earth and tried to draw too much power from the solar cells at the wrong time.

[ NathanBridges/JPL - 32 - 10:07:15 ]
RE: [Sarah/MadisonWI-SarahT/EdgewoodHigh] Hi Nathan! Thanks for sharing you time with us. What kinds of courses would you recommend in high school & college for someone who is interested in a career such as yours?
Hi Sarah, Science, math, and engineering classes are good, especially if you are talented in those areas. There are a number of fields you can pursue in space science. I am a geologist, so I took a lot of Earth science courses. Other subjects you can pursue are astronomy, physics, and engineering.

[ NathanBridges/JPL - 36 - 10:08:35 ]
RE: [Megan-Mrs.Haywood/OakviewElem.] Why does Mars look red?
Megan, The red color comes from iron oxide, similar to the rust you see on metal. Most of Mars is covered with iron-rich dust that has been oxidized.

[ NathanBridges/JPL - 37 - 10:09:20 ]
RE: [Pedro-PedroAriasstudentuniversityofCrdobaARGENTINA] Iím a geology student in Argentina. I like to work in Tectonic of the others planters, but what masters and Ph. D. I need to do that?
Pedro, You should probably get a masters and Ph.D. in geology. --Nathan

[ Oran/NASAChatHost - 39 - 10:10:35 ]
RE: [Alexandre/MacaBrasil-Mrs.Alexandre/LenepUenf] Hello Mr Oran How are you? It is the first opportunity I have to participate at chat room of the Quest Time On Line. If you can give some special hints to guide new recruits I'd appreciate
Alexandre, we suggest that your read the questions and answers posted by others, as well as the autobiographical information about Nathan Bridges (http://quest.arc.nasa.gov/mars/team/bridges.html) before posting questions to the chat room. Additionally, please read the chat instructions which were posted earlier. Use your 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 ]
RE: [Renae-Mrs.Taylor/ChautauquaElementary] 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 system. --Nathan

[ 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 meteorites. --Nathan

[ 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. --Nathan

[ 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. --Nathan

[ NathanBridges/JPL - 109 - 11:24:22 ]
RE: [Stephanie/Edmonton] Should we terraform Mars?
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. --Nathan

[ 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: http://wwwflag.wr.usgs.gov/USGSFlag/Space/GEOMAP/PGM_home.html

[ NathanBridges/JPL - 122 - 11:29:07]
RE:[ Manfred] Dit the APXS discover organic molecules?
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 ocox@mail.arc.nasa.gov 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 minutes.

[ 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 Nunes Barreto

[ 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.!!!!!!!!!!!!!!!!!!!!!!


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