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Space Scientists Online QuestChat

November 19, 1998

Sten Odenwald
Astronomer & Author of "Astronomy Cafe" Web Site
Raytheon ITSS, Washington, DC

[ Sandy/NASAChatHost - 15 - 10:22:14 ]
Hello! Today's QuestChat with astronomer Sten Odenwald will begin in approximately 40 minutes. Today Sten will answer your questions about the sun and the solar system. Please, no astronaut-related questions (Sten is an astronomer!). Be sure to read Sten's bio BEFORE coming to the chat-- http://quest.arc.nasa.gov/sso/team/odenwald.html

[ Sandy/NASAChatHost - 16 - 10:24:26 ]
RE: [MrRains-Mr.Rains/SuttonElem.School] Checking this out. We've never participated in a project like this before.
Hello Mr. Rains! I'm here and I'm listening! You're right, the chat is still about 40 minutes away. Sten Odenwald will start answering questions at the top of the hour. I'm really glad you could make it! Web chats are a lot of fun. Do you have any questions before we start?

[ Sandy/NASAChatHost - 24 - 11:01:05 ]
RE: [MrSimoneaux/EastAscensionHS-Mr.Simoneaux/EastAscensionHS] Hello from Louisiana!
Hi Mr. Simoneaux and East Ascension High School! Glad you could make it back for another chat! We will begin momentarily...

[ Sandy/NASAChatHost - 36 - 11:04:33 ]
RE: [Giancarlo/Italy-Mr.Visani/ScuolaMediaStataleAlfredoOrianiCasolaValsenioItaly] Good evening from Italy. I'm a teacher in a Middle School. I have some questions from my students. Can I write them all at once or one at once?
Please send you questions one at a time or it will take too long for Dr. Odenwald to answer them. Thanks :-)

[ Odenwald/Astronomer - 38 - 11:04:46 ]
RE: [Katelyn/SanVicenteISD-DJ/SanVicenteISD] Does the sun really pulse?
Yes the sun does actually vibrate in many hundreds of different frequencies...especially a very prominent 5-minute oscillation. Visit the Stanford University's Helioseismology web site for details

[ Odenwald/Astronomer - 40 - 11:06:03 ]
RE: [MrSimoneaux/EastAscensionHS2-Mr.Simoneaux/EastAscensionHS] When did ya'll start the Sun Project
About a month ago...in the next month or so we will have a number of solar scientists and engineers doing this 'chat' service to help you all understand how the sun works, and how the earth is affected...cool stuff.

[ Odenwald/Astronomer - 47 - 11:07:49 ]
RE: [Rachel/SanVicenteISD-DJ/SanVicenteISD] What evidence is there that supports that is another planet/s past Pluto?
There is no real evidence so far. The orbits of the outer planets are known to be 'chaotic' which can make it look like a large object might be perturbing their orbits. So far, about 70 objects have ben detected beyond the orbit of neptune, but these all seem to be smaller than about 300 kilometers...probably comet nuclei in the making.

[ Odenwald/Astronomer - 50 - 11:08:36 ]
RE: [Josh-JoshConverse/WilliamsTechMiddleSchool] Dr. Odenwald, what do believe in the field of extraterrestrial life?
There probably are lots of extra terrestrials...but they are mostly bacteria of various species....but we dont know. really.

[ Odenwald/Astronomer - 51 - 11:09:14 ]
RE: [Lisa-Lisa/BayportH.S.] I was wondering if you could tell me some things on space technology. I'm doing a project on space technology for my sociology class
That's an incredibly broad topic...I cant rally answer a question that broad.

[ Odenwald/Astronomer - 56 - 11:11:20 ]
RE: [MrSimoneaux/EastAscensionHS2-Mr.Simoneaux/EastAscensionHS] How long will the SOHO Probe be in Orbit?
SOHO...the Solar heliospheric Observatory, will probably stay at the L1 lagrange point for many years before various tuggs and pulls eventually move it out of this gravitationally stable location 1.5 million miles sunward of the earth...as for science. It is now in its extended mission which will only last about 2 years...after that, NASA will probably have to decommission it to make way for supporting other space observatories...even if SOHO is still working.

[ Sandy/NASAChatHost - 60 - 11:12:34 ]
EVERYONE: LET'S HOLD UP ON THE QUESTIONS FOR 5 MINUTES! There is only one Sten answering all of your questions and he's typing as fast as he can! Thanks!

[ Odenwald/Astronomer - 61 - 11:12:35 ]
RE: [MrSimoneaux-Mr.Simoneaux/EastAscensionHS] What causes the sun to pulsate or vibrate?
We dont know for certain...but it has a very noisy interior containing deep convection cells. the acoustic energy from these cells probably drive some of the oscillation modes.

[ Odenwald/Astronomer - 65 - 11:14:34 ]
RE: [Rhalie-Mr.Simoneaux/EastAscensionHS] How do solar flares affect communication signals on earth?
Solar flares produce intense pulses of X-rays which, when the hit the ionosphere, cause enhanced daytime ionization. This causes short-wave 'black outs' that last from 20 minutes to several hours, until chemical 'recombination' processes can reduce the number of ions per cubic centimeter, to the normal daytime levels produced by ultraviolet photo-ionization.

[ Odenwald/Astronomer - 70 - 11:17:01 ]
RE: [Lisa-Lisa/BayportH.S.] What about Near Earth Objects? I heard that a comet or asteroid is supposed to hit sometime in 2030. I also heard that it will miss us by a hair. Do you know anything about this?
new data shows that the object predicted early this year to impact the earth on October 28, 2028 will actually miss us by up to 600,000 miles. This doesnt mean, however, that among the 20+ asteroids discovered each year that in the future one of these will not impact us. There is currently a list of over 100 asteroids which are 'on watch'. their orbits come so close to the earth that they are considered serious hazards.

[ Sandy/NASAChatHost - 72 - 11:17:30 ]
EVERYONE: There are 80 people signed up for today's chat with Sten. He is going to try very hard to answer everyone's questions, so if you can, please hold up sending anymore questions for another 5 minutes so that Sten can catch up! Thank you :-)

[ Odenwald/Astronomer - 74 - 11:18:35 ]
RE: [Rachel/SanVicenteISD-DJ/SanVicenteISD] Is it possible to live on another planet? What life support would you need to bring with you to live on another planet?
Surr...its possible, but setting up such a colony is very expensive...even prohibitively so. So long as we stay in the inner solar system out to Mars, manned exploration is relatively cheap. the costs escalate dramatically as you look towards Jupiter and beyond which are 1/2 a billion miles away or more.

[ Lisa-Lisa/BayportH.S. - 76 - 11:19:02 ]
Thanks Dr. Odenwald, I appreciate it. You don't know how much this is helping me. :)

[ Odenwald/Astronomer - 79 - 11:20:18 ]
RE: [Katelyn/SanVicenteISD-DJ/SanVicenteISD] How long do you think it will take to get the International space station up in space?
If all goes smoothly..they will stay on schedule. many people have worried that there is a good probability of a shuttlke accident involving loss of life, or that an unusual barrage of solar storms will make spacewalking a real hazard. These factors could delay assembly by many years...we just dint know...but now that we have started the process we have to finish it.

[ Odenwald/Astronomer - 84 - 11:22:44 ]
RE: [Josh-JoshConverse/WilliamsTechMiddleSchool] In about how many billion years will it take for the sun to "burn itself out"?
The best calculations indicate that in 6 billion years the sun will become a red giant and incinerate mercury, venus and probably the earth. by 500 million years from now, the normal gradual increase in the suns luminosity will have increased terrestrial average temperatures by anywhere from 20 to 50 degrees. the biosphere will contract and the amount of water vapor in the atmosphere will increase as the oceans start to evaporate. By 1 billion years the earth will be locked in a venus-style greenhouse with am extinct biosphere.

[ Odenwald/Astronomer - 89 - 11:24:07 ]
RE: [Ava-Mr.Simoneaux/EastAscensionHS] What would happen if the Earth's axis was not tilted???
We would not have the kinds of seasons we now have...the details are rather complicated depending on what latitude you were on.

[ Odenwald/Astronomer - 90 - 11:24:55 ]
RE: [AshleyMrSimoneaux-Mr.Simoneaux/EastAscensionHS] How long are comets life span?
We dont know...some comets come back for thousands of years...like Halley's Comet. Others plunge into the sun nearly on their first orbit.

[ Odenwald/Astronomer - 91 - 11:25:44 ]
RE: [Brynn/EastAscensionHighSchool-Mr.Simoneaux/EastAscensionHS] Is it possible to create an artificial ozone layer to cover the already enlarging hole?
No..the simplest thing to do is to stop destroying it in the first place. the hole will eventually heal itself in a few decades...so the experts say.

[ Odenwald/Astronomer - 93 - 11:26:43 ]
RE: [Asha-Mr.Simoneaux/EastAscensionHS] Is it possible for people to stand on an asteroid? (with proper space equipment)
You probably can, at least on the largest asteroids...but the gravity is so weak that for most asteroids you can jump into orbit..or escape that way.

[ Sandy/NASAChatHost - 98 - 11:28:57 ]
RE: [Pat-PatSotile/AscensionParish] Hello, We are from Lowery Middle School. We are glad to enter this chat.
Hi Pat! Welcome to our chat with astronomer Sten Odenwald! We're glad to have you here today. Do you have a question for Sten?

[ Odenwald/Astronomer - 99 - 11:29:02 ]
RE: [AshleyMrSimoneaux-Mr.Simoneaux/EastAscensionHS] Do any other planets have windstorms or tornadoes besides the sun and Jupiter? If so, what causes them?
Hmm..tornadoes and hurricanes are caused by the motions of warm and cold air masses on planets that rotate. This is such a general prescription that mars, jupiter, saturn, uranus and neptune have them as a good bet...but actually I wonder about uranus and neptune because if the atmospheres are too cold and homogeneous, there will not be enough differential winds to start the process going. Probably need to talk to a meteorologist!

[ Odenwald/Astronomer - 102 - 11:30:00 ]
RE: [Brynn/EastAscensionHighSchool-Mr.Simoneaux/EastAscensionHS] How hot is the sun?
It depends on where you are...in the center its about 15 million K, at the surface its 5,770 K, in the corona its about 2 million K...all due to different physical processes going on.

[ Odenwald/Astronomer - 104 - 11:31:14 ]
RE: [Brynn/EastAscensionHighSchool-Mr.Simoneaux/EastAscensionHS] what is the nearest star?
Proxima Centauri is at 4.2 light years...but actually it is in orbit around Alpha Centauri at 4.3 light years.

[ Odenwald/Astronomer - 108 - 11:32:45 ]
RE: [JoshClauseMrSimoneaux-Mr.Simoneaux/EastAscensionHS] Do you think Halley's Comet will ever die out?When?
Its hard to really say...it is losing mass, so certainly in the distant future it will have to be reduced to a pile of non-volatile rocks and meteoroids...but given its present orbit and the forecasts, it looks like it is good for perhaps another few dozen returns at least.

[ Odenwald/Astronomer - 113 - 11:35:02 ]
RE: [Brynn/EastAscensionHighSchool-Mr.Simoneaux/EastAscensionHS] How hot is the sun's middle layer?
Hmm..it depends on how you define 'middle layer' At 487,000 km from the center the temperatire is 1 million K, and by 627,000 km the models predict a temperature near 310,000 K. between 689,000 and 696,000 just below the surface the temperature drops from about 52,000 K to 5,770 K.

[ Sandy/NASAChatHost - 115 - 11:36:07 ]
RE: [Pat-PatSotile/AscensionParish] Can we set up a videoconference with someone at a later date?
Pat: Send me email to sdueck@quest.arc.nasa.gov

[ Odenwald/Astronomer - 116 - 11:36:32 ]
RE: [Pat-PatSotile/AscensionParish] Do you think that life exists on any other planets?
yes I do..but it is strictly a BELIEF. I think the universe is quite filthy with bacteria of all types. There are probably even quite a few planets with complex organic life...It just seems to me that 'life' is very hardy and can adapt to lots of different physical environments...at least bacterial life forms.

[ Odenwald/Astronomer - 119 - 11:37:46 ]
RE: [Brynn/EastAscensionHighSchool-Mr.Simoneaux/EastAscensionHS] How large is the sun in comparison to other stars?
According to mass...the most massive star is about 200 times the mass of the sun...the least massive is about 0.04 times the suns mass. Physical dimensions span the gamut from neutron stars at 20 km radius, to Mu Cephi with a radius nearly the size of neptunes orbit

[ Odenwald/Astronomer - 121 - 11:39:42 ]
RE: [Eric/EastAscensionHighSchool-Mr.Simoneaux/EastAscensionHS] Why would you explode if you didn't have a suit on in space
You wouldnt explode at all...why do you think the 'pound' puts stray dogs into decompression chambers/ All that happens is that your blood and intercellular fluids evaporate out of your body and you, essentially, dehydrate, in a matter of an hour or so. Presumably you can survive 10 - 20 seconds in a pure vacuum without a space suit...but your skin capillaries will make you look like a blue mess after a while.

[ Odenwald/Astronomer - 126 - 11:41:43 ]
RE: [Jim-JimChamberlain/AZTek] Why is the ozone layer helpful, but ozone at ground level is harmful? Also you can buy ozone generating machines for your home.
Ozone in the upper atmosphere absorbs ultravilooet radiation that tries to reach ground...ozone at the ground is very harmful and a toxin to many body chemical cycles...Home Ozone generators produce very little ozone and gives your noes the illusion of fresh air..or it locks onto the surface of dust particles and makes them reactive so that they can be washed out of the air.

[ Odenwald/Astronomer - 128 - 11:42:48 ]
RE: [interestedpersons-Mr.Simoneaux/EastAscensionHS] How long did it take you to complete your education
Hmmm..it took 4 years in college, and then another 6 years in graduate school at Harvard to get my Phd in 1982.

[ Sandy/NASAChatHost - 130 - 11:43:43 ]
RE: [Mr.Simoneaux/EastAscensionHS] bye
Goodbye! Thanks so much for joining us today! Hope you will come back and chat with us again!

[ Odenwald/Astronomer - 133 - 11:44:57 ]
RE: [AshaMrSimoneaux-Mr.Simoneaux/EastAscensionHS] What signs or talents should I be on the lookout for to know if I want to be an astronomer
Hmm...No intimidation about math..a precocious curiosity about physical science leading to a high aptitude in physics compared to your other classmates. You might also have astronomy as your hobby, which means you read Sky and telescope magazine to keep up with the discoveries...and so you have a basic knowledge of terms.

[ Odenwald/Astronomer - 135 - 11:46:25 ]
RE: [Torey-Mr.Simoneaux/EastAscensionHS] Why did you whant to be an astronomer
I thought space was really cool when I was 10 years old...and the Science Fiction program Outer Limits got me excited about aliens in space. I was astonished that scientists actually knew a LOT about space, and I wanted to learn all about it too..

[ Odenwald/Astronomer - 136 - 11:47:44 ]
RE: [Eric/EastAscensionHighSchool-Mr.Simoneaux/EastAscensionHS] I thought that the only reason you can survive on earth is because of equal pressure. In a vaccuum, there is unequal pressure. I thought6 that the presure on the inside of your body would push outward until you exploded because there is no presure pushing against it?
No..human skin is not elastic like a balloon...it is pretty darn tough stuff. But even skin breaks down as the cells inside it lose their water...you turn into a dried up Inca Mummy.

[ Odenwald/Astronomer - 137 - 11:49:28 ]
RE: [KoRn/EastAscensionHighSchool-Mr.Simoneaux/EastAscensionHS] What keeps the earth from being pulled into the sun or into other planets?
Something called 'inertia'. It is constantly trying to move in a straight line consistent with its speed of 30 km/sec, but the suns gravity keeps pulling it at right-angles to its motion. When you work the physics, you end up with an elliptical orbit.

[ Odenwald/Astronomer - 138 - 11:49:56 ]
RE: [Giancarlo/Italy-Mr.Visani/ScuolaMediaStataleAlfredoOrianiCasolaValsenioItaly] Do you know Italian astronomers and cooperate with them?
Actually..no I dont.

[ Sandy/NASAChatHost - 139 - 11:50:09 ]
EVERYONE: There are about 10 minutes left in today's chat. The Quest Team would like to know what you think about our chats. Please take some time to fill out a SHORT SURVEY to let us know how we're doing: http://quest.arc.nasa.gov/qchats/qchat_sureveys

[ Odenwald/Astronomer - 141 - 11:52:03 ]
RE: [Josh-JoshConverse/WilliamsTechMiddleSchool] I want to do a computational science project on a topic relating to either life in the universe or black holes, however, I am only taking algebra. Any suggestions for a more limited topic?
Hmm..that's a big challenge. The problem is that most of the really exotic problems that have 'algebra' in them, require you to know a level of physics that you will not really acquire until you are in college. If 'E = mc^2' or 'F = ma' seem hard to intuitively underdstand, there are a lot more difficult concepts that also require just algebra to really understand.

[ Odenwald/Astronomer - 144 - 11:53:09 ]
RE: [Josh-JoshConverse/WilliamsTechMiddleSchool] do you think stuff in science fiction will soon become real, like warp speed etc.etc.
No..but I am, and have always ben, an avid science fiction fan. I love Babylon V and am very sad its 5th season is over...sob...sob!

[ Sandy/NASAChatHost - 145 - 11:54:20 ]
RE: [Giancarlo/Italy-Mr.Visani/ScuolaMediaStataleAlfredoOrianiCasolaValsenioItaly] Thank you very much. I liked this experience!
We're so glad you joined us today! Please come back and chat with us again! A new chat schedule will appear soon at: http://quest.arc.nasa.gov/sso

[ Odenwald/Astronomer - 146 - 11:54:29 ]
RE: [Bob-Mr.Hitt/GraysHarborCollege] Why is the release of energy so much greater for Helium fusion than Hydrogen fusion?
For that, you will have to examine the curve of 'binding energy per nucleon' sorry I cant be more helpful in this chat session on this technical point!

[ Odenwald/Astronomer - 148 - 11:57:41 ]
Ok everyone..SO long for now!! Great questions one and all!! Dr. odenwald

[ Sandy/NASAChatHost - 150 - 11:58:24 ]
EVERYONE: Today's chat with astronomer Sten Odenwald has come to an end. Congratulations on all the fantastic questions you sent in-- you did your homework! Check the chat schedule for future chats with Sten: http://quest.arc.nasa.gov/sso Chat with you again very soon!


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