ASTRONOMY BIG BANG THEORY CME (CORONAL MASS EJECTIONS)
COMPOSITION OF THE SUN CORONA FLARES LIFE CYCLE OF THE STARS
MAGNETISM OZONE ROCKETS SATELLITES SOLAR CYCLE SOLAR MAXIMUM
SOLAR OBSERVATORY SOLAR PHYSICIST STARS SUN TEMPERATURE OF THE SUN
ASTRONOMY (CAREERS IN)
QUESTION:
How much money are astronomers paid? What are the
necessary prerequisites to become an astronomer of the sun? What other
scientific fields do the space scientists study in order to work on the sun?
from Andy/per 5
ANSWER:
The salary of an astronomer depends on where they work. In a
University, the range is $25,000 at the start up towards $80,000. In
industry, it can be twice that, and yes, there are astronomers in industry,
for example, Lockheed-Martin. However, virtually every astronomer I know
would probably happily work for nothing because we love it! To become an
astronomer of any sort, you first must learn physics, and this also requires
mathematics through advanced calculus. You also need to know as much as
possible about computers. Other helpful fields are electronics and optics.
SCIENTIST: John Leibacher, National Solar Observatory, Kitt Peak
QUESTION:
Do you believe in the "Big Bang Theory"? If
not, what is your hypothesis? Could you please explain a little bit of it to
us? from Team 6/per 3 McQuone
ANSWER:
I think that the Big Bang theory is probably correct. We have
evidence that there was a massive explosion at the beginning of the
expansion of the universe. This evidence is known as the 3-degree background
radiation, and it was detected using a radio telescope built at Bell labs.
This telescope measured a very small radio signal that appeared to come from
every direction in the sky. Calculations showed it could be explained by
assuming that outer space has an average temperature of 3 degrees above
absolute zero, or about 457 degrees below zero Fahrenheit. This, in turn, is
the temperature you would get if there was a Big Bang 15 billion years ago
and the universe was still cooling off from the explosion.
SCIENTIST: John Leibacher, National Solar Observatory, Kitt Peak
QUESTION:
Will Y2K possibly interfere with the tracking of CMEs? And
if it does can that cause even more trouble? Kalee
ANSWER:
Hello Kalee! Y2K won't bother us too much, unless all our
checking to be sure that our software works wasn't thorough enough. However,
even if there is a problem, we should be able to fix it rather quickly. All
of us at NASA (especially those who work with computers) think that the Y2K
hype is far too overinflated! If our computers have problems, we'll have to
fix them, but after that we'll be back to tracking CMEs right away!
Hopefully there won't be any big ones right at midnight on New Year's Day!
Barbara Thompson
SCIENTIST: Barbara Thompson, NASA Goddard Space Flight Center
QUESTION:
How many CMEs come off the Sun every day? Sean
ANSWER:
Sean - currently we're getting about 5 CMEs per day, hopefully
more! We hope you're interested in watching the CMEs with us as we get
toward solar maximum. Day to day, the number of CMEs varies a lot. During
solar minimum, the average number of CMEs per day is only 1-2. Sometimes
there are none, some days there are more, but on average just a few. If
there is a region on the Sun which is really active, it can produce a lot of
eruptions. Right now, we're closer to solar maximum, so we are dealing with
a lot more CMEs. Today we've already had four! We'll probably get quite a
few more by the end of the day. During solar maximum, we can get up to 10
CMEs per day - can you imagine keeping track of all of them?? Dr. Barbara
Thompson
SCIENTIST: Barbara Thompson, NASA Goddard Space Flight Center
QUESTION:
Brad Portnoy in Mike Reynolds' class at Cranbrook MS
wants to know What is in a CME and what causes them?
ANSWER:
Hello Brad! What is a CME and what causes them? What a
question! We've spent a lot of time trying to understand them. Fortunately,
the people who studied these things when they were first discovered came up
with a very good name for them: coronal mass ejections. They are the
ejection of mass from the Sun's corona or atmosphere. They can contain a
billion tons of solar material (mostly hydrogen) and can go several million
miles of hour out into space. As to the cause of CMEs, there are several
possibilities: they all have to do with the storage and release of magnetic
energy. Most of us believe that the magnetic energy builds up, and
eventually the release of this energy occurs (like a sneeze!). Sometimes the
release of energy occurs as a flare (so it causes a temporarily bright
energized region on the Sun) and sometimes the magnetic fields are ejected
in the form of a CME. Thanks for your questions! Dr. Barbara Thompson
SCIENTIST: Barbara Thompson, NASA Goddard Space Flight Center
QUESTION:
Since the Sun is made up of gases would anything ever be
able to go through it?
ANSWER:
The gases that the Sun is made of are very hot, and the
pressure at the center is enormous. Nothing would be able to survive inside
the Sun.
SCIENTIST: Frank Hill, National Solar Observatory, Kitt Peak
QUESTION:
How is the corona *really* heated? Lots of news releases
have indicated that the magnetic field is doing it, but it's not clear that
reconnection can do the job. For example, evolution of a potential magnetic
field doesn't release *any* energy at all!
ANSWER:
I wish I knew!! ;-) Seriously, we have some hypotheses [
a.k.a. guesses, or suspicions ] but no clear answers. 30 years ago everyone
thought that the corona was heated by sounds waves, generated by the
bubbling near the surface, that "crashed" up in the corona where
the density of matter decreases, rather like water waves crashing on the
beach as the depth of the water gets shallower. That doesn't appear to work
- the energy "crashes" before it gets up into the corona. We know
just from the beautiful loops that we see in the corona, that magnetic
fields exist there, and that they are constantly changing. Magnetic fields
can store more than enough energy to head the corona, but how it gets
released involves a bit of "hand waving" at the present in my
humble opinion. As you say just moving a field around doesn't do anything. A
magnetic field is just a way of describing an electric current that is
flowing somewhere, and the dissipation of that current - the "light
bulb" if you will - still needs to be understood. So, it's a mystery -
for now. BUT, I'm confidant that we'll understand it some day soon, that's
the fun of science. There are oodles of questions, and we're making good
progress answering some of them, and asking even more along the way!!
SCIENTIST: John Leibacher, National Solar Observatory, Kitt Peak
QUESTION:
Can the sun's fire really be fire? because fire needs air to burn.
Raymond Age 8
ANSWER:
The sun is made of really hot gas, so hot that the atoms it's made of
have lost some of their electrons. This kind of matter is called plasma. The
plasma on the sun, because it is so hot, releases energy we can see (visible
light) and energy we can't see (radio, ultraviolet, infrared, X-rays, and
gamma-ray light). So the sun is not really "burning" in the sense that
we think of when we watch a fire burn. When wood burns, in part it's changing
from a solid into a plasma and needs air to do so. In the sun, there are no
solids! So the two processes are actually quite different, even though they look
the same to us in pictures.
SCIENTIST: Elizabeth Newton, NASA Marshall Space Flight Center
QUESTION:
How will the solar flares, clouds and radiation affect
the satellites during solar maximum? What can be done to prevent damage?
Will particles directly hit people? from Team 4/McQuone
ANSWER:
Hello Team 4 - First I must applaud the way you phrased the
question, because you mentioned solar flares, clouds, and radiation - all
are important, and we must consider all of them when we begin our
"preparations" for solar maximum. We primarily worry about
energetic particles - these can come from solar flares (from the sun) or
they can come from magnetic clouds (the clouds can impact earth and cause
the particles to become energized). These can affect spacecraft components
in a number of ways. First, if the electronic components become too highly
charged by these particles, they can damage the components. There are some
cases where the charge became so high that it destroyed the power supply!
Also, energetic particles, when hit memory storage devices, can "flip
bits" and cause "artificial memory problems." To prepare for
these, we monitor spacecraft charging more closely, and we write software
which looks harder for inconsistencies which might be flipped bits. As for
radiation - it's quite fascinating what it can do - if we get a large
increase in energetic light, it can cause the atmosphere to expand and
increase the drag on spacecraft. During a few cases, more than a thousand
spacecraft were "lost" because all the extra drag caused the
tracking programs to be unable to follow them. To prepare for this, we have
to enable the tracking programs to be ready for sudden slow-ups! There are a
lot more things we do in space to prepare for solar max - including monitor
the sun more closely. I hope you'll do that with us! Dr. Barbara Thompson
SCIENTIST: Barbara Thompson, NASA Goddard Space Flight Center
QUESTION:
Can the sun create a solar flare that is so big that it
could reach or engulf the earth? from Team 2/ per 5
ANSWER:
There is no evidence that the Sun has flares that are large
enough to effect life on Earth. Other stars similar to the Sun have "Superflares"
but they appear to be caused by a Jupiter class planet really close to those
stars. The Earth's atmosphere and magnetic field are very good shields. Eric
Christian for Live from the Sun
SCIENTIST: Eric Christian, NASA Goddard Space Flight Center
QUESTION:
Could the impact of the solar flares on the earth once
have been so great that it caused the destruction of the dinosaurs? from
April, Kristy, Kelly and Jessica S./per 7
ANSWER:
The Earth's magnetic field and atmosphere are very good
shields. There is no evidence that any solar flare has been severe enough to
effect life on Earth. Eric Christian for Live from the Sun
SCIENTIST: Eric Christian, NASA Goddard Space Flight Center
QUESTION:
Has a solar flare ever been large enough to affect the
heating of Earth?
ANSWER:
No, in terms of heat (thermal energy) flares don't have enough
to affect the Earth's temperature. The amount of extra heat that comes out
of the Sun due to a flare is really pretty miniscule compared to what the
Sun puts out on a regular basis.
SCIENTIST: Elizabeth Newton, NASA Marshall Space Flight Center
QUESTION:
How long can a solar flare last? Lauren
ANSWER:
A solar flare can be as quick as a few seconds, or as long as
thousands of seconds! That's a pretty big dynamic range. It's a big mystery
why some are so fast, while others are so long.
SCIENTIST: Elizabeth Newton, NASA Marshall Space Flight Center
QUESTION:
We know that the solar flares will probably affect
satellites, but is it possible for particles from solar flares to make it
through the atmosphere to affect us? from Brittany, Jermaine, Gina, and
Meghan per 7
ANSWER:
Hi gang! A very small number of particles from solar flares
reach Earth, and most scientists do not believe there is any additional
danger to us from flare particles during solar maximum - there just aren't
enough to be dangerous. People in airplanes can be exposed more to the
particles, because they don't have as much of the atmosphere to shield them.
However, the absolute worst dosage they can receive from a solar flare is no
more severe than a chest X-ray. Therefore, the primary effects of these
energetic particles reach us through other processes. They can cause
magnetic activity which *can* be noticed at Earth. Still, it is important to
research the solar flare particles - they can cause all sorts of effects,
and they're very important to astronauts! I hope you're interested enough to
keep watching the Sun through the school year. Dr. Barbara Thompson
SCIENTIST: Barbara Thompson, NASA Goddard Space Flight Center
QUESTION:
At what point in the 5 billion years of the life of the sun will
life as we know it on earth change? How will it change? from Marquis/ per 4
McQuone If the sun blows up, could people live elsewhere in the universe?
from Travis/per 4 McQuone
ANSWER:
Actually, we think that the Sun is already nearly 5 billion years
old, and that it will live for another 5 billion making a total lifetime of
10 billion years. Our models predict that about 5 billion years from now,
the Sun will have burnt more than 50% of the hydrogen fuel in its core. At
that time, it will contract rapidly as the weight of the outer layers will
no longer be supported by the pressure of the heat in the core. The Sun will
shrink in size by about 15% over a few days, and then the temperature in the
core will rise to where helium can be burned. Now, helium burns at a much
higher temperature than hydrogen, so the pressure in the core of the Sun
will increase, and the Sun will expand enormously. It will expand so much
that all of the planets out to Mars will be under its surface. At that
point, life on Earth would cease. People might be living elsewhere if they
were able to find and travel to another planet that could support them.
SCIENTIST: Frank Hill, National Solar Observatory, Kitt Peak
QUESTION:
What will happen to the planets during the sun's cycle? from Caitlin/
per 4 McQuone
ANSWER:
The Sun will expand so much that all of the planets out to Mars will be
under its surface. At that point, life on Earth would cease. People might be
living elsewhere if they were able to find and travel to another planet that
could support them.
SCIENTIST: Frank Hill, National Solar Observatory, Kitt Peak
QUESTION:
How do scientists determine how long the sun will exist?
from Matt/ per 3 McQuone
ANSWER:
We determine how long the Sun (and any star) will exist by
making models of it in a computer. We use physics and math to calculate
various quantities that describe the conditions of the matter and energy as
we go from the very center of the star to the outside. Some of these
quantities are temperature, density, and composition (what the matter is
made of). We can match the model to things we can observe about the Sun and
other stars, like how hot their surface is and how big they are. We can then
watch how these model stars change in the computer as the hydrogen is burned
and converted into helium and other elements. This lets us predict the
future of the Sun.
SCIENTIST: Frank Hill, National Solar Observatory, Kitt Peak
QUESTION:
Do you think the prediction of the sun going out in 5
billion years could be wrong? Do you think it could end any time soon? I was
just wondering because a lot of predictions can go either way, right or
wrong? from Josh/per 4 McQuone
ANSWER:
We may be off by 10% (500 million out of 5 billion), but don't
worry about this one. It won't happen for a very long time. We can now check
our models thanks to helioseismology, the study of the sound inside the Sun.
The models are pretty good.
SCIENTIST: Frank Hill, National Solar Observatory, Kitt Peak
QUESTION:
Is it possible for the sun to become a black hole? If so,
could it suck in the earth? from Daniel/per 2 McQuone
ANSWER:
The sun cannot become a black hole because it does not have
enough mass. The sun will end its life as a white dwarf.
SCIENTIST: John Leibacher, National Solar Observatory, Kitt Peak
QUESTION:
One video showed how the sun affects the earth's magnetic field.
Can it ever breakthrough the atmosphere and affect me directly? from Scott.,
Jennifer, Eddie and Deepthi/per 1 McQuone
ANSWER:
I'm guessing that your question concerns the charged electrical
particles from the Sun rather than the heat and light. The lowest altitude
that solar wind particles can reach is about 25 miles, well above the ground
and the altitude at which passenger jets fly. When these particles do hit
the Earth's atmosphere, they create the Aurora Borealis and Australis about
60 to 80 miles up in the atmosphere.
SCIENTIST: Frank Hill, National Solar Observatory, Kitt Peak
QUESTION:
Seeing that the sun is a magnetic star, if a giant magnet
was put out in space, would the sun be attracted to it? from India, ENiola.
Cpette. Steven per 1/McQuone
ANSWER:
Yes, although it would take a REALLY big magnet, in other
words, one with a mass comparable to that of the sun. Eric Christian for
Live from the Sun
SCIENTIST: Eric Christian, NASA Goddard Space Flight Center
QUESTION:
If we did not have magnetic poles blocking the Solar
Winds of the sun, what would result? from PJ/per 5
ANSWER:
Hi PJ! That's a question that isn't just exciting to ask, but
it's also important. When people talk about visiting other planets and
spending extended periods in space, they consider the possibility of having
energetic radiation hitting them without the protection of the Earth's
magnetic fields. Astronauts wear radiation monitors which keep track of how
much exposure they're getting - when they've gotten too much exposure, they
have to retire, or they're under too much risk of developing cancer. We'd
certainly be in the same situation without the Earth's magnetic field,
though the Earth's atmosphere helps shield us as well. However, if the
Earth's atmosphere has to observe *all* of the energetic particles, it can
heat it so much that the Earth's atmosphere could expand out to space and
partially disappear! So would we have worse trouble without having an
atmosphere or because of additional radiation? Take care! Dr. Barbara
Thompson
SCIENTIST: Barbara Thompson, NASA Goddard Space Flight Center
QUESTION:
Does the sun effect our ozone layer and can the ozone layer be wiped out
totally? from Erick, Colby, Ciara, Kisha/per1 McQuone
ANSWER:
The sun helps to create the ozone layer by breaking apart oxygen molecules
into single oxygen atoms. These single atoms can then recombine with other
oxygen molecules to form ozone. Ordinary oxygen molecules have 2 atoms,
ozone has 3. The ozone layer is vital to our survival as it absorbs most of
the ultraviolet (UV) radiation from the sun. Too much UV causes cancer.
There are many other processes that affect the ozone layer, like stirring up
the Earth's atmosphere and injecting other chemicals. The worst chemicals
are fluorocarbons contained in spray cans and air conditioners. If we
produce enough of those chemicals, we could indeed wipe out the ozone layer.
SCIENTIST: Frank Hill, National Solar Observatory, Kitt Peak
QUESTION:
For how long can a sounding rocket collect data?
ANSWER:
About 10 minutes. It will vary a bit with each payload. The
SERTS payload has been reflown a number of times and between each flight
modifications have been made. Usually these modifications make the payload a
few pounds heavier. The highest point in the flight is now about 10 miles
lower than the earliest flights and the observation time is about a little
less as well.
SCIENTIST: Les Payne, NASA Goddard Space Flight Center
QUESTION:
If the sun is so hot, how can they get a satellite close
enough to tell anything about it? Can the sun's temperature change at
different times of the year? from Cassie H./McQuone
ANSWER:
All of the current satellites (ACE and SOHO for example) are a
lot closer to the Earth than to the Sun and study the Sun from a long
distance away (150 million kilometers or 92 million miles). There is a
mission planned for the future called Solar Probe which will get within 3
million kilometers (2 million miles) of the Sun. It has an ablative shield
(which vaporizes protecting the rest of the satellite). You can find out
more about Solar Probe at http://umbra.nascom.nasa.gov/spd/solar_probe.html
The Sun's temperature changes with time over it's 11 year cycle, but not by
very much. Eric Christian For Live from the Sun
SCIENTIST: Eric Christian, NASA Goddard Space Flight Center
QUESTION:
What is the longest time a satellite can be used? What is
the closest distance that a satellite can get to the sun? from Chris,
Trinese, Carly, Julia/per 1 McQuone
ANSWER:
Well, IMP-8 launched over 26 years ago and is still going
strong! So some satellites last a very long time. About the closest distance
that a satellite can get to the sun: Solar Probe, due to launch in 2003, is
being designed to get within 4 solar radii.
SCIENTIST: Beth Jacob, NASA Goddard Space Flight Center
QUESTION:
How close could a person in a satellite get to the sun
before they burn? from Rachel/per 5
ANSWER:
t depends upon how good your cooling system is. There is an
unmanned spacecraft (Solar Probe) which is being designed to get within 3
million kilometers (2 million miles) of the Sun, but it needs a special
ablative shield which evaporates away, protecting the rest of the
spacecraft. If you had a manned spacecraft, you probably couldn't get that
close without a lot of work. Eric Christian for Live from the Sun
SCIENTIST: Eric Christian, NASA Goddard Space Flight Center
QUESTION:
How and when was the 11 year cycle of the sun discovered? What
observations were made to determine that it was a cycle? from Rachel, Nicole,
Brendan, Sam/per 4 McQuone
ANSWER:
The 11-year sunspot cycle was discovered in 1843 by Schwabe. He simply
counted the number of sunspots that were visible on the Sun every day and then
noticed that the number went up and down with a period of around 11 years.
Schwabe was an amateur astronomer, not a professional, and even today amateurs
still make valuable contributions to astronomy.
SCIENTIST: Frank Hill, National Solar Observatory, Kitt Peak
QUESTION:
Does the Sun get larger as it goes through the years?
ANSWER:
The Sun has some oscillation in its size, but it's quite small
- people have done measurements by looking at the passage of other stars
behind the Sun. However, the total amount of oscillation is small. The main
change in the Sun's apparent size is due to Earth's orbit around the Sun -
during the winter, we are closer to the Sun, and during the summer we are
farther away. Therefore, the Sun looks 3% larger during the winter than it
does in the summer. If you want to see a movie of how the Sun shrinks and
grows in size, and to see how the tilt of the Sun varies throughout the
year, take a look at: http://urania.nascom.nasa.gov/~zowie/coords/orbital-movie.html
However, the Sun will expand a *lot* when it depletes its core of fuel, and
begins the next stages of its life. Fortunately, that's not going to happen
for billions of years, so we're all safe! thanks for the question! Dr.
Barbara Thompson
SCIENTIST: Barbara Thompson, NASA Goddard Space Flight Center
QUESTION:
When the Sun dies will it explode or just disintegrate?
Courtney
ANSWER:
It will do neither. It will first expand into a red giant
star, and all of the planets out to Mars will be inside the star. The Sun
will then contract and eventually turn into a white dwarf star, which is
very small but very heavy. In fact, all of the matter in the Sun will then
be in a sphere the size of the Earth! A teaspoon of white dwarf matter
weighs more than New York City. After it becomes a white dwarf, it will
simply cool off until light no longer comes out of it.
SCIENTIST: John Leibacher, National Solar Observatory, Kitt Peak
QUESTION:
During Solar Maximum what will be the biggest effect we
will notice on Earth? Maureen
ANSWER:
Hello Maureen! Well, I'm not sure if you want to know whether
you want to know what the biggest effect we'll personally notice is, or
whether you want to know how they'll affect space systems and other things
which we don't notice during the average day. I'll just assume you want to
know how you'll personally experience it. Certainly the most interesting
thing about solar maximum that we'll be able to see on the ground is aurora
borealis activity - some people call them the "northern lights."
They're spectacular! Huge colorful shining curtains of light in the sky
caused by energetic particles hitting the atmosphere. During solar minimum
you usually only seem them in the extreme northern parts of the United
States, but during solar max they've been observed as far south as Puerto
Rico! We hope you're interested in chasing coronal mass ejections with us,
because if we see a big one, it might mean that if we go outside at night we
can see an aurora. Other possible effects are not as pleasant. Some people
have temporarily lost power, or television signals, or their cell phones
have stopped working. Some of these sound like effects that normal weather
storms cause - so "space storms" are also as exciting and
important! Take care! Barbara Thompson
SCIENTIST: Barbara Thompson, NASA Goddard Space Flight Center
QUESTION:
Is there a particular reason that the observatories are
domed shaped? from Colleen, Sara, Laura and Sally
ANSWER:
Now that's an insightful question! The reason is that
telescopes need to be able to look at any place in the sky, including low
down. The best way to do this is have a slot in the roof, and to have the
roof rotate. The best way to do all that is to have a dome for a roof. There
are other shapes in use: Small telescopes frequently have a cube-shaped shed
that just rolls away leaving the entire telescope out in the air. Also,
there is now a trend towards 8-sided roofs with sides that completely open.
This design allows air to flow across the telescope and makes everything the
same temperature as the outside air. This reduces turbulence and improves
the quality of the images.
SCIENTIST: John Leibacher, National Solar Observatory, Kitt Peak
QUESTION:
How did you know you wanted to be a solar scientist?
Robert
ANSWER:
Robert, my story is a bit unusual. I didn't really know until
I got to graduate school. I have always been interested in physics and in
mathematics, but could never make up my mind. When I went to college, I
couldn't choose a major. I was having trouble deciding between journalism,
art history, physics, math, and political science -- you can see that I was
all over the board! By my third year, I noticed that I seemed to be taking a
lot of physics courses, so I decided to be a physics major. When I applied
to graduate school, I couldn't choose between high energy particle physics,
solid state physics, or astrophysics. In the end, I found a research group
full of people that I liked, and stuck with that. I think that, at some
level, any field at all has enough interesting problems to keep a curious
person going. So solar is definitely my field now, but I don't think it
would have been the only one for me. The first time I remember being
interested in the Sun was during the solar maximum in the late 1970s. I was
a boy scout, and on a campout I remember getting up at dawn and watching the
Sun come up. I saw some dark blemishes on the Sun and asked my dad about 'em.
Fortunately he knew what they were (sunspots, caused by intense magnetic
fields on the surface), and ever since I've been intrigued about our nearest
star. I'll pass on some good advice I got from my father when I was younger.
When charting your career, don't stress out over trying to pick a single
field you'll follow for the rest of your life. Focus on what you'd like to
do for the next few years. The long run will take care of itself, as long as
you focus on the intermediate run. Cheers, Craig DeForest
SCIENTIST: Craig DeForest, NASA, Goddard Space Flight Center
QUESTION:
What causes the stars in constellations to sty together
and never separate? Like the Big Dipper? Do others rotate or float freely?
from Daniel/ Per 4 McQuone
ANSWER:
Actually, all the stars in the sky are moving in different
directions at very high speeds, typically 20 miles per second. However,
since they are very far from us, it looks like the constellations have not
changed since they were first recorded 10,000 years ago. If we could go
backwards or forwards in time by several million years, then the
constellations would look very different. There would be no Big Dipper.
SCIENTIST: John Leibacher, National Solar Observatory, Kitt Peak
QUESTION:
What caused the density to increase at the core of the nebula
cloud that formed the sun? from Chris/per 2 McQuone
ANSWER:
Usually, it is the the gravitational attraction between the
particles in the dust cloud that starts the whole process off. This
attraction slowly contracts the cloud and increases the density in the core.
It is also possible that a blast of radiation and matter from a nearby
supernova could speed up the process.
SCIENTIST: Frank Hill, National Solar Observatory, Kitt Peak
QUESTION:
What causes the sun to rotate in that mysterious pattern?
from Maggie/Per 2 McQuone
ANSWER:
Sorry to be slow in getting back to you, I was tied up in a
meeting.... ;-( That the Sun rotates is not a mystery; when you pull the
plug in the bathtub and the water rushes out it almost never goes straight
down the drain, but ends up swirling to the right or the left at a good
clip. There's always a teeny tiny difference in the water going to one side
or the other of the drain, and that "organizes" the water that
follows. The same thing happens when a star is formed from a cloud of gas in
"interstellar space". AND, as the cloud collapses to form the star
[ in our case, the star we are living with - the Sun ] the rotation speeds
up more and more as the star condenses. A good analogy is of a skater
spinning around, who pulls in their hands and the rotation speeds up a lot.
Try it on a stool that rotates BUT BE CAREFUL!! We thought that the Sun
should be rotating much faster than we observe it to be doing, so there must
have been a lot of rotating matter ejected as the Sun was forming, but even
to how the rotation changes inside the gaseous Sun ***IS**** a mystery. BUT,
it's a mystery we think we can solve. "We" means "you",
and the next generations of scientists. Join the fun of the search!! g'luck
John Leibacher
SCIENTIST: John Leibacher, National Solar Observatory, Kitt Peak
QUESTION:
How were people able to find out about the history of the
sun, like how it formed? We were not there to see it. from Lee, Krissi,
Lavondrick/ per 5 McQuone
ANSWER:
Good question!!! Actually, and EXCELLENT question which goes
to the heart of how science functions. We can observe the Sun today - it's
mass, size, temperature, brightness, and that's about it until very recently
- as well as other stars - once we figured out that the Sun was a star. Then
the questions start to flow, like "why" and "how". For
example, it wasn't until 50 or 60 years ago that people had an idea of where
the Sun's energy came from. A hundred years ago people thought that the Sun
was shining from gravitational energy from it's collapse from a gas cloud,
and that seemed reasonable enough. One - very important - test of a
scientific hypothesis is that it make testable predictions, and the idea [
"theory" ] that the Sun's energy came from the gravitational
energy of its collapse predicted that the Sun should use up all of that
energy in a few 100 thousand years [ and then die out ]. On a human time
scale, there weren't any arguments against the prediction BUT geologists
showed that there were rocks on the Earth that are MUCH older than this, so
the theory was thrown out, and we now "know" that the Sun shines
because helium fuses into hydrogen. I put "know" in quotation
marks because we don't really "know" anything, we just have a
pretty good description of the observations that explains the basic
properties of the Sun and other stars, and is consistent with what we know
about the Earth, long before human beings were around. BUT, one thing IS
certain, what we "know" today isn't the whole story, and there are
lots of mysteries still to be solved. That's ONE reason that science is so
much fun!! best wishes, and thanks for the great question! John Leibacher
SCIENTIST: John Leibacher, National Solar Observatory, Kitt Peak
QUESTION:
Is it possible for anything to destroy the sun, like
comets? from Kristy, Kelly, Jessica S., April
ANSWER:
Compared to the sun, a comet is miniscule. In fact, if the sun
were the size of a basketball, the earth would be about the size of a small
pencil eraser. Comets are even smaller than that. So a comet crashing into
the sun would not have much effect. (There are some cool pictures of
sun-grazing comets out on the internet at http://umbra.nascom.nasa.gov/comets/SOHO_sungrazers.html).
As for anything else? It's not likely that anything else could destroy the
sun, other than its running out of fuel to burn.
SCIENTIST: Elizabeth Newton, NASA Marshall Space Flight Center
QUESTION:
Is it possible for their to be a life form that could
exist on the sun? from Derrick, Katrina, John/per 7
ANSWER:
I think it is very unlikely that any life form could live
where the coolest temperature is 4000 degrees.
SCIENTIST: John Leibacher, National Solar Observatory, Kitt Peak
QUESTION:
Is is possible that the sun is a bigger factor in the
destruction of the atmosphere that air pollution? from Jessica H. per 7
ANSWER:
I don't think so, Jessica. The Sun certainly sends out a lot
of energy into space and is responsible for warming our planet and allowing
life to flourish. But really things like volcanic gases and air pollution
are much more immediate and direct agents that change the chemical
composition of our atmosphere. Also, the Earth's magnetic field protects our
Earth and its atmosphere from the Sun's most harmful particles that stream
in the solar wind. So it's not very often that a solar event is going to be
that destructive to our atmosphere.
SCIENTIST: Elizabeth Newton, NASA Marshall Space Flight Center
QUESTION:
Are there more neutrons than protons in the sun or are
there an equal number? Blake George at Cranbrook M.S. Mr. Reynolds' class
ANSWER:
There are more protons because there is much more hydrogen
than anything else in the Sun, and hydrogen has a single proton and no
neutrons.
SCIENTIST: John Leibacher, National Solar Observatory, Kitt Peak
QUESTION:
Will the Sun ever get too hot that it will effect animal
and human life? Jodi
ANSWER:
The Sun, in it's old age, will get larger and eventually
become a red giant star, at which point the Earth will be to hot for us. But
that is billions of years in the future. The Sun does get hotter and cooler
with time, but the effects are relatively small. But ice ages and hot
periods such as the Jurassic may be partially due to the Sun getting hotter
and colder. Eric Christian for Live from the Sun
SCIENTIST: Eric Christian, NASA Goddard Space Flight Center
QUESTION:
How hot will the core be when it is burned out?
ANSWER:
Probably warmer than the current 15 million degrees, but none
of the half a dozen scientists here are experts in stellar modeling. Sorry.
Eric Christian for Live from the Sun
SCIENTIST: Eric Christian, NASA Goddard Space Flight Center
QUESTION:
Is it possible to duplicate the temperature of the sun on
earth? from Mack/per 4
ANSWER:
The Sun is different temperatures at different places. Some places,
like the photosphere are not that hot & we can replicate those
temperatures in a laboratory. Other places are very hot & we can only
replicate temperatures of millions of degrees in nuclear bombs. We can't do
it at all in a controlled way.
SCIENTIST:
Terry Kucera, NASA Goddard Space Flight Center
QUESTION:
Since the scientists have not probed
inside the sun, how do they know the actual temperature of the inside of the
sun?
from Kate/ per 4 McQuone
ANSWER:
We know what the energy source must be - nuclear fusion is the only
thing that will give enough energy for long enough. From that we can
estimate the temperatures. We can measure the details using helioseismology
- measuring the vibrations of the Sun, see http://solar-center.stanford.edu/heliopage.html
SCIENTIST:
Terry Kucera, NASA Goddard Space Flight Center
QUESTION:
Does the temperature inside the sun ever change? from Christina/per 4 McQuone
ANSWER:
It is different in
different places. It is probably pretty consistent, but I don't think we can
measure it well enough to tell if it is changing in small ways. Terry
SCIENTIST:
Terry Kucera, NASA Goddard Space Flight Center
