Thu Feb 18 12:35:50 1999 [ Linda/NASAQuest - 0 - 11:32:28 ]
This room is reserved for the chat with Therese Kucera, solar physicist, at the Solar and Heliospheric Observatory scheduled for Thursday, February 18, 1999 - 11AM PST (2PM EST and 7PM UT). See her profile at: http://quest.arc.nasa.gov/sso/team/kucera.html

[ Linda/NASAQuest - 7 - 10:50:34 ]
RE: [Mike] hello i need help on a research paper about The importance of the NASA
Hi Mike, This room is for a specific chat. You may join us, but please look at our expert's profile so that you can ask questions specific to her expertise. Thanks

[ Linda/NASAQuest - 10 - 10:51:30 ]
RE: [Mark/K4] My name is Mark Alvidrez and I'm a second grade teacher. My students are Spanish speakers learning about our solar system in English. They have a high level of interest in our solar system. It is an honor to participate in this chat.
Hi Mark, We're delighted to have you with us today. We will be opening the chat room very soon (about 9 minutes). Stay tuned.

[Linda/NASAQuest - 11 - 10:52:38 ]
RE: [ThereseKucera/Physicist] Hi Linda. I am here.
Hi Therese! You're early. I'll start feeding in questions as they come. Mark? Do your students have questions ready?

[ EastAscension - 15 - 10:59:47 ] Hi East Ascension High is here!!!

[ Eric - 16 - 10:59:59 ] hi from east ascension high school

[ ThereseKucera/Physicist - 18 - 11:00:03 ]
RE: [ Mark/K4 - 13 - 10:57:09 ] Do you have a favorite planet?
Hmmm, well I am kind of a fan of the Earth! Other than that, not particularly. They are all interesting in different ways. I guess I find the smaller ones interesting, because I can imagine people living on them more easily.

[ ThereseKucera/Physicist - 20 - 11:01:18 ]
RE: [Mark/K4] Why is the sun so hot?
The Sun is heated in its center by nuclear fusion - the proessure is so high there that atoms are smooshed together. This causes then to give off lots of energy.

[ ThereseKucera/Physicist - 23 - 11:02:29 ]
RE: [EastAscension] How long does it take for the solar winds to reach earth?
It usually takes a few days, say 3 or 4

[ ThereseKucera/Physicist - 24 - 11:03:38 ]
RE: [Mark/K4] How old is the sun?
we think the Sun is about 5 billion year old and that it has another 5 billion or so more years to go as a regular "middle aged" star

[ ThereseKucera/Physicist - 27 - 11:06:28 ]
RE: [Eric] have they found out any new things about the sun lately?
Well, recently we have been finding out more things about the source of the solar wind. The solar wind is a flow of charged particles which comes out of the Sun all the time. It comes out at different rates in different places. There have recently been observations made by the SOHO spacecraft (the one I work with) showing material moving outwards from "coronal holes" (areas usually found near the Sun's poles) and at the edges of cells which form on the Suns surface.

[ ThereseKucera/Physicist - 31 - 11:09:00 ]
RE: [Amber] Are solar tornados and solar quakes similar to those on earth?
In some ways. "solar quakes" are caused when material hitting the Sun's surface durring a solar flare cause sound waves go through the Sun's interior. We can study these waves to find out what the Sun is like inside. This is a like Earth quakes on Earth, except with those the vibrations are caused by different things.

[ ThereseKucera/Physicist - 32 - 11:10:00 ]
RE: [Amber] Are solar tornados and solar quakes similar to those on earth?
Solar tornadoes are columns of material that seem to be rotating around. In that way they are like Earth tornadoes, but otherwise they are probably pretty different.

[ ThereseKucera/Physicist - 34 - 11:13:00 ]
RE: [Michelle] Therese, Have any solar physicist estimated the end of our Sun's life?
yes, we think it will leave its current stage of life in about 5 billion years. Then we expect it to expand into a "red giant" star. After being a huge cool red giant for a while it will lose its outer layers and become a "white dwarf" star.

[Linda/NASAQuest - 35 - 11:13:05 ]
RE: [Emily] what does it mean when it says T*D/S?
I'm not sure what you're referring to. Could you clarify?

[ ThereseKucera/Physicist - 39 - 11:16:09 ]
RE: [Eric] What is the highest temperature recored on the sun?
We thing the Suns core (center) is at about 15 million degrees C. That is the hottest part The "surface" is about 5500 degreess C and then in the Sun's outer atmosphere, the corona, the temperature goes back up to a million degrees or more.

[ ThereseKucera/Physicist - 42 - 11:17:16 ]
RE: [Sara] Therese, Will the Sun become a supergiant?
We do expect the Sun to become a "red giant" some day. It still will not get as large as some of the really big supergiant stars, though - the Sun is a medium sized star

[ ThereseKucera/Physicist - 45 - 11:18:41 ]
RE: [ CharlotteMary - 22 - 11:02:23 ] asked How many years will it take for a complete revolution?
I am not quiet sure what you are asking here. The Sun takes just under a month to turn on its axis. To a complete a revolution around the galaxy takes much longer. I don't remember off the top of my head - I'd have to look it up.

[ ThereseKucera/Physicist - 46 - 11:20:15 ]
RE: [Mark/K4] Why is the sun so important to the solar system?
The Sun is what holds the solar system together! Almost all the mass in the solar system is in the Sun and everything else is just orbiting around it. Without the Sun everything would go flying off. The Sun also provides most of the energy in the solar system.

[ ThereseKucera/Physicist - 48 - 11:22:24 ]
RE: [Ava] Do you know anything about the solar instrument VIRGO!
The VIRGO instrument on the SOHO spacecraft studies the Sun's vibrations. We use these vibrations to try to figure out what is inside the Sun. VIRGO was built in Europe by people from a number of different countries.

[ ThereseKucera/Physicist - 49 - 11:23:47 ]
RE: [Jasmine] Therese, Do you think that the Sun is a Rosetta Stone of astronomy? If so, how?
People say that because it is right in our back yard and we can study it more carefully than any other star. If we don't really understand the Sun, how can we say we understand stars? or galaxies?

[ ThereseKucera/Physicist - 50 - 11:25:10 ]
RE: [Mark/K4] Would you like to study the sun from space one day?
Well, I already am - I study information about the Sun sent down from space every day. As for me going up there myself, it would be neat...

[ ThereseKucera/Physicist - 54 - 11:28:11 ]
RE: [TimMcCollum/CharlestonMiddleSchool] Therese, My students are being a bit shy right now so I'll ask a question. Plasma, as we are studying states of matter, is a somewhat difficult material to describe. Could you explain what it is as it relates to the Sun? Thank you :)
Plasma is what you get if you heat something up a lot. Have they heard of electrons and protons? These are charged particles. If you heat up a gas enough the atoms fall apart leaving charged particles. The Sun is very hot and is made of plasma. This makes it different from soemthing that isn't a plasma because plasma react with electric and magnetic fields. These are what cause solar activitie - things like sunspots, flares and mass ejections.

[ ThereseKucera/Physicist - 56 - 11:30:00 ]
RE: [Mark/K4] We know that the sun is a star, but why is it so BIG???
Well there is a _lot_ of stuff there - it takes up some space! We think that solar systems start as big clouds of gas and dust and gravity pulls most of it to the center.

[ ThereseKucera/Physicist - 58 - 11:32:29 ]
RE: [Amber] How strong is the sun's pull of gravity
Pretty strong. If you could stand on the Sun with out vaporizing you'd weigh more (I can't remember exactly how much more at the moment). The Sun's gravity is what keeps all the planets in their orbits.

[ ThereseKucera/Physicist - 60 - 11:34:30 ]
RE: [Kasheena] What kind of interesting challenges does your job show?????
A lot of my job is working with data that gets sent down from spacecraft. It can be a claenge to work with the data correctly so that you understand what it really means and don't get confused. Also, once you understand something, it can be a challenge to explain it to other people.

[Linda/NASAQuest - 62 - 11:36:15 ]
RE: [jason] como estas?
Hola Jason, Aunque no te parezca, tus preguntas y notas se estan viendo desde la NASA. Con un poquito de paciencia podras verlas in el salon de chat.

[ ThereseKucera/Physicist - 64 - 11:38:20 ]
RE: [BeersStreet] What is the most interesting observation you have made to date of the sun using SOHO?
THE most interesting? I think some of the most interesting ones have been the solar quakes and solar tornadoes someone mentioned above. Also I like the new results about the solar wind which I mentioned above as well. Some other things: SOHO along with a group of space craft called the International Solar Terrestrial Physics Program (ISTP) have helped us trace solar magnetic clouds (known as Coronal Mass Ejections or CMEs) all the way from the Sun to the Earth. That has been really interesting. The CME's srupt off the Sun and the ones pointed in this direction interact with the Earth's magnetic field. These can cause problems with satelites and power outages and such.

[ ThereseKucera/Physicist - 66 - 11:41:46 ]
RE: [BeersStreet] Does the sun have geographical features like we have mountains on Earth?
Not in the same way. The sun is made of plasma. You can think of it as a very hot gas or liquid. Things move around in a fluid more than they do on the surface of a solid planet like the Earth. Still there are features on the Sun which can last many months. Sunspot groups can last that long, so do solar prominences. The "coronal hole" features near the poles can remain for years near the minimum in the sunspot cycle (the number of sunspots and amount of solar activity goes up and down every 11 years).

[ ThereseKucera/Physicist - 68 - 11:45:01 ]
RE: [HASSAN] HI I'M HASSAN FROM MONTREAL IS IT POSSIBLE THAT OUR SOLAR SYSTEM IS A LEFTOVER GAS FROM ANOTHER GALAXIE
Hi. We think the solar system is made up of gas that comes from an older star that blew up. We think this because in our solar system we find many heavy elements that we think can only be formed in stars. Some really heavy elements (for instance, Copper lead) can only be formed in supernovae (large stars which explode)

[ ThereseKucera/Physicist - 71 - 11:48:06 ]
RE: [BeersStreet] How close can a satalite get to the sun without burning up?
That is something NASA wants to find out. We are currently working a a mission called "Solar Probe". Solar Probe is supposed to get as close to the Sun as it can. We are hope to be able to get to about 4 times the Sun's radius away (I just did a quick calculation, which may not be right, but I think that is about 3 million kilometers)

[ ThereseKucera/Physicist - 76 - 11:50:33 ]
RE: [Michelle] Therese, What would the impact be like if a distant planet were to collide with our Sun?
Planets are not usually very big, so I think the Sun would just gobble it up. We see comets going into the Sun all the time. If it was something very large, say another star, it could messup the orbits of planets in the solar system. It is more likely that somehting would go into orbit around the Sun than it would be for it to crash right into it.

[ ThereseKucera/Physicist - 77 - 11:51:47 ]
RE: [Amber] Do solar tornadoes and quakes contribute to the solar winds?
Solar quakes probalby do not. soar torandoes might be realted - they tend to occr at the boarders of the cells on the Sun where we have discovered material moving outwards. This is very new stuff, though, so we don't know all the conections.

[ ThereseKucera/Physicist - 78 - 11:53:54 ]
RE: [Amber] How far from Eatrh can you go, while remaining in Earth's gravitational pull?
Hmmm. Well the location of the SOHO space craft is one indicator. It is at a place where the gravities of the Earth and Sun are balanced. It is about 1.5 million kilometers (900,000 miles) away from the Earth.

[Linda/NASAQuest - 79 - 11:55:23 ]
We are nearing the end of the hour. I know there are many questions unanswered. We will handle what we can, and then invite you to join the next chat in the Space Scientists Online project. Check http://quest.arc.nasa.gov/sso/chats for more information.

[ ThereseKucera/Physicist - 80 - 11:55:57 ]
RE: [Jasmine] Therese, Why did you decide to become a Solar Physicist
Well, I wanted to be an astronomer since I was pretty young. The Sun is a star, so it is "astronomy" but it also affects our daily life, which makes it interesting too. Also, on a more proactical level, an astronomer has to specialize in something & I know a professor in graduate school who needed a student to help him study the Sun. There are lots of other things I find interesting too.

[ ThereseKucera/Physicist - 81 - 11:58:28 ]
RE: [Kasheena] What does the Coronal Diagnostic Spectrometer do?????
The Coronal Diagnostic Spectrometer (CDS)... a spectrometer is an instrument which breaks light up into different wavelengths of light. You have probalby seen a prism do that to turn Sun light into rainbows. CDS does this with ultraviolet light. We can learn a lot about the Sun by studying the ultraviolet light it produces. CDS is what discovered the "solar tornadoes" for instance.

[ ThereseKucera/Physicist - 82 - 11:59:20 ]
RE: [BeersStreet] As the sun becomes a red giant what is the gradual process that Earth will go through?
Basically the Earth will heat up and burn. Some people even think the Sun will get so big that in will absorb the Earth completely

[ ThereseKucera/Physicist - 85 - 12:01:03 ]
RE: [emily] What does the solar ultraviolet measurements of emitted radiation do??
solar ultraviolet measurements of emitted radiation SUMER is a lot like CDS (see my last answer) except that ot looks at different wavelengths of light. It helped us make some of the discoveries about the solar wind that I mentioned at the begining of the chat.

[ ThereseKucera/Physicist - 86 - 12:01:44 ]
RE: [Eric] At the rate of pollution in the earth today, how long will it take before the ozone layer is too weak to protect us?
That is not something I in particular study - it would be a good question of an atmospheric scientist.

[ ThereseKucera/Physicist - 89 - 12:04:13 ]
RE: [CharlotteMary] Is it true that UV rays are the strongest when it is cloudy?
Again that is more a question for an atmospheric scientist. However I think they are not stronger when it is cloudy. It is just that people don't worry about the Sun as much when it is cloudy, so they fprget the UV rays can come through clouds and burn them. That is why you hear warnings about UV rays on cloudy days.

[ KasheenaCharlotteMaryEmily - 90 - 12:05:17 ]
Thank you for answering our questions!!! --students We feel this is an excellent learning tool and we intend to utilize this mode as much as possible. The students gave very positive reviews overall. Thank you very much for your help. Wendell Salmons Tech Ed Teacher L.T.M.S.

[ ThereseKucera/Physicist - 91 - 12:06:02 ]
RE: [ Mark/K4 - 63 - 11:37:42 ] asked What kind of a star is the sun?
The Star is called a "G2" star. This is a kind of smallish, middle aged star. It is yelowish color. Stars which are more white and blue are hotter, and stars which are redder are cooler.

[ Linda/NASAQuest - 92 - 12:06:19 ]
I want to thank Therese for taking the time to answer so many questions. She will answer just a couple more. Thank you students also for you well-thought out questions. Join us again next week.

[ ThereseKucera/Physicist - 95 - 12:10:03 ]
RE: [Jasmine] Therese, Between the years 1640 and1710, why was there an absence of sunspots, and how did it coincide with the period of very cold temperatures?
The period you are talking about is called the "little ice age" it was colder than usual in a number of places. Because there were very few sunspots or auroras (=northern and southern lights) durring the same period, we thing there is connection, but we don't really know what it is.

[ ThereseKucera/Physicist - 96 - 12:12:02 ]
RE: [TimMcCollum/CharlestonMiddleSchool] from Beth/ Why does the sun give off solar flares?
We don't understand all the details. In general we think that the Sun's magnetic field builds up a lot of energy and then releases it very quickly, sort of like what happens when you release a stretched and twisted rubber band.

[ ThereseKucera/Physicist - 98 - 12:13:01 ] RE: [TimMcCollum/CharlestonMiddleSchool] from Beth/ Why does the sun give off solar flares?
There is a web page about solar flares at http://hesperia.gsfc.nasa.gov/sftheory/

[Linda/NASAQuest - 97 - 12:12:40 ]
Thanks again Therese! This has been a very informative time. Again students, there will be more opportunity to ask your questions at the next chat. See http://quest.arc.nasa.gov/sso/chats.