[ Sandy/NASAChatHost - 0 - 08:44:12 ]
Hello and welcome to the Space Scientists Online chat room! Today's expert is Astronomer Sten Odenwald from the Goddard Space Flight Center. Sten is ready to begin chatting so start typing everyone!!

[ StenOdenwald/Astronomer - 3 - 11:03:46 ]
RE: [Eleanor/GWHS/DC] Hi Sten-- can you give us the latest scoop on Mars Polar Lander? I heard ther was a possibility for receiveing a signal sometime today...
Hi! From what I have heard, there was supposed to be another opportunity for the lander and its penetrator probes to get in touch with the Orbiter via a UHF omni-directional transmitter, but as of this morning that didnt happen. Ypu might check the NASA website at http://www.nasa.gov and look at their lead story.

[ StenOdenwald/Astronomer - 6 - 11:07:48 ]
RE: [Sharon/RCucamongaCA] I'd like to know more about your background in astronomy. I read your bio but I can't find where you describe what you do in your office on a day to day basis. I'm in high school and astronomy is my favorite subject. Any advice for me?
Hi Sharon, My day-to-day work has changed quite a bit in the last 5 years. It used to be that I spend all of my time doing research...at the computer, manipulating data, extracting information about interstellar cloud densities, temperatures, or looking for imbedded infant stars. At the same time Id be working on a paper, writing it up for publication based on earlier research results. Today, I still do this about 1/4 of the time, but most of my time has moved into the space science education area. I develop study guides and classroom activities that use the data from my satellite, IMAGE, and help students master their math and science skills. I also answer a lot of questions!

[ StenOdenwald/Astronomer - 7 - 11:09:00 ]
RE: [JoshCederCreek] Is there really a hole in the ozone? If there is, should I really be worried about it? And, if I should be worried, what can my class do to help?
Hi! I dont do ozone research...but there really is a seasonal 'hole' that appears over both the arctic and antarctic regions during their local winter periods. Its been tracked by satellites for many years now.

[ StenOdenwald/Astronomer - 10 - 11:10:48 ]
RE: [JoshCederCreek] Is there really a hole in the ozone? If there is, should I really be worried about it? And, if I should be worried, what can my class do to help?
I would be worried about it, because what is also going on elsewhere is that more UV-b gets to the ground and so you need more sunblock than you did 10 years ago. Skin cancer rates have already started to increase. FOr me, that's a big worry. I don't do as much sunbathing as I did when I was in my 20s.

[ StenOdenwald/Astronomer - 12 - 11:13:49 ]
RE: [JoshCederCreek] What can you tell us about global warming-- is the theory really true?
Global warming is not a theory. It is measurable, and there is not a single scientist that denies that the global average temperatuyres during the last 100 years have increased significantly. What is 'theoretical' and being disputed by a VERY small number of scientists, is that humans are responsible for this. SOme say that this warming is caused by the sun itself. That's a theory too. others say that it is caused by other geological processes...that is also a theory.

[ StenOdenwald/Astronomer - 15 - 11:17:56 ]
RE: [EAStudents] Hi! We're studying about black holes in science class and we don't understand them at all? Can you descirbe what they look like and how do astronomers go about finding them? Where does the hole go to?
Black holes can be formed from very massive stars that explode and have their cores implode. We think this is a very common process, and some of your favorite stars are destined to become black holes. It is hared to describe, in words, what black holes are like because they can only be described mathematically. We have no experience with them, so we have no words to describe them. It is true that light cannot escape from these dense objects. What would be inside one is hard to say because the mathematics only deal with 'perfect' ones. Mathematical calculations do say, though, that inside black holes, time and space are 'reversed', and most of them should have a 'Singularity' in their centers if they arent rotating too rapidly.

[ StenOdenwald/Astronomer - 17 - 11:19:36 ]
RE: [JeremyEAStudents] How close could the Earth get to the Sun before it starts burning up? And, is that a possibility in the next million years???
At 35 million miles, the orbit or Mercury, the earth would loose most of its atmosphere. You would probably have to get within 5 million miles before its hot enough to melt the crust. At some point, inside this distance, the tidal forces would distort the earth into a football, then a cigar, then ...fffftttt.

[ StenOdenwald/Astronomer - 18 - 11:20:31 ]
RE: [JeremyEAStudents] How close could the Earth get to the Sun before it starts burning up? And, is that a possibility in the next million years???
No...the earth cvannot fall into the sun. Eventually, however, when the sun becomes a red giant, the suns surface will come out to meet the earth...in 6 billion years. We will all be dead in another 700 million years though.

[ StenOdenwald/Astronomer - 22 - 11:23:45 ]
RE: [KristieAbott] What's the gravity on Mars. If I weight 105lbs on Earth, how much would I weight on Mars?
You would weigh 105 pounds x 374/982 or about 50 pounds or so...you can do the math. ;>

[ StenOdenwald/Astronomer - 24 - 11:26:32 ]
RE: [KaseyLaCanadaCA] Hi Sten--do you really think that a human colonly will exiost on mars in our live times (yours and mine- i'm in high school)? Would you like to be one of the first members of this colony?
Hmmm...in the next 40 years ( i'll be a young man of 87!) I cant imagine. I have turned into something of a pessimist in my old age. We do things 'cheaply' and as you see in the loss of the MArs Polar Lander, some things are naturally expensive to do. I would never want to be a colonist under the current funding and engineering conditions where pinching pennies has become the new way to do technologically complex and risky missions.

[ StenOdenwald/Astronomer - 26 - 11:27:43 ]
RE: [MelissaG] What is your facoribe planet and why? I love Saturn because it seems so mysterious!
Saturn has always been my favorite too, but now that we know so much about Europa, I am now 'into' satellites of the planets in the way I could never get excited about the planets themselves.

[ StenOdenwald/Astronomer - 27 - 11:29:29 ]
RE: [MrsFitzpatrick/5th] Dr. Odenwald- This is my first time into a chat room and my head is swimming with all of the possbilities of contact with a REAL Nasa scientist! Do you give talks to classrooms, visit in person, etc?
Yeah...I visit classrooms a lot in the Washington DC area...but you would be surprised how hard it is for scientists to get invited into classrooms. Teachers work very hard to get you students through the material you need to master, and having an outsider visit can sometimes be too disruptive...but I love doing it!!!

[ StenOdenwald/Astronomer - 30 - 11:30:58 ]
RE: [Tim] I would rather see humans return to the moon first rather than TRY to get to Mars... what are your thoughts on this?
Yes..I agree. Psychologically, you can thrive on the moon because Mother Earth is always close by. But on Mars, the aloneness would be dreadful. I dont think people realize just how cut off from humanity these colonists will be. The psychological strain will be incredible.

[ StenOdenwald/Astronomer - 32 - 11:32:50 ]
RE: [MelissaG] So what is the most exciting thing about Europa to you? Is Europa the one that Voyager found a volcano on?
Europa is the satellite of Jupiter that has the crust made of ice...with icebergs and other cracks. We are pretty convinced from the images that, at least at one time, it had an interior that was liquid water. Whether it still does is an exciting prospect, because that means it could have living systems...bacteria probably, swimming around inside.

[ StenOdenwald/Astronomer - 33 - 11:33:39 ]
RE: [MattinBurbank] Did you ever want to become an astronaut???
No..I always wanted to become an astronomer. Space scares the daylights out of me...even more now that I know something about it!

[ StenOdenwald/Astronomer - 35 - 11:35:59 ]
RE: [KristieAbott] We've been studying Uranus and wonder why its tipped over on its side. Can you tell us...
The best idea we have is that, when the solar system was still young, the cratering data says that there were some very big objects orbiting the sun..hundreds of objects 500 to 1000 kilometers across....mini-planets actually. There are still a few of these left. Anyway, during the last stages of planet formation, they will be hit by bigger and bigger things, and the planets that had the highest tilts got hit by some very big planetoids that actually tipped them over before they were absorbed.

[ StenOdenwald/Astronomer - 36 - 11:37:20 ]
RE: [SharonRCucamongCA] How long does it take to design a robotic missiion to Mars? And does the atmosphere on Mars affect robiots?
It takes a couple of years beforee launch, then another year to get there, for smaller missions like the ones we are sending now..but of course, you need decades of satellite design experience to have a 'conveyor belt' run that fast.

[ StenOdenwald/Astronomer - 38 - 11:40:10 ]
RE: [WilliamC] Can you tell us what the core of Mars is made of and how far down we'd have to drill before we'd reach it?
Hi! We really dont know, but it probably isnt molten anymore because MArs doesnt have a magnetic field like the earth does.

[ StenOdenwald/Astronomer - 40 - 11:41:35 ]
RE: [MattinBurbank] Hi I have a question about Mars for you. Does the Mars Global Surveyor spacecraft that is alreay orbiting mars go over the same areas time after time? If it does, is there a posssibility that it could find the Polar Lander if it crashed into Mars?
Hi! yes, it is in an orbit that will pass over the landing site, but unfortunately the resolution on the cameras is too low to see something that small...unless it left a crater!

[ StenOdenwald/Astronomer - 42 - 11:44:06 ]
RE: [MrsFitzpatrick/5th] I read in your autobiography about your young daughters. How do you present astronomy to them? Will you encourage them to go into science for a career?
They both love to hear Papa talk about space. They are 5.5 and 7 years old, and they have now seen many things through our telescope so they are really 'savy' about space. Both of them knew the order and names of the planets by heart before they were 4 years old. I go very very easy on them to avoid overwhelming them with too much too soon. Yes I will encourage them to become scientists. It is the best career in the world!

[ StenOdenwald/Astronomer - 45 - 11:46:34 ]
RE: [Tim] There are currently 3 movies in production that are about mars missions. I'm guessing that they will be realistic like "Apollo 13". Will these movies make the public more aware and more interested/supportive of space? Is nasa behind these proudctions?
Yes, NASA has provided 'technical advisors' so that you will get a pretty realistic idea of what might happen during these trips, and what an outpost will look like...as for the liberties that the stories will take for other 'alien' circumstances, we have no idea what will happen. My first guess, is that any living bacteria will have other things to do when we arrive than say 'Dinner's on! The fresh meat has arrived!'

[ StenOdenwald/Astronomer - 46 - 11:47:42 ]
RE: [Tina/SpokaneWA] Why is the sun yellow?
It's actually colorless, but our eyes have cones that sense different bands of radiation and provide something we sense as 'color'. The universe is really black and white.

[ StenOdenwald/Astronomer - 47 - 11:49:09 ]
RE: [Tina/SpokaneWA] Can you explain in easy terms how the sun works?
Gravity compresses matter, matter heats up and the heat pressure causes a balance to happen between these forces. This balance point happens when the corte temperature is 15 million degrees and thermonuclear fusion can release enough energy to provide the heat pressure.

[ StenOdenwald/Astronomer - 49 - 11:51:17 ]
RE: [Tina/SpokaneWA] Does the sun have weather like the earth?
It has weather, but not like on earth because the gases on the sun are in a state called a plasma. These gases can create powerful magnetic fields, and the convecting gases can amplify these fields to produce sunspots and flares among other things. Its a much more violent place that the earth.

[ Sandy/NASAChatHost - 51 - 11:53:33 ]
EVERYONE: THERE ARE ABOUT 5 MINUTES LEFT... Sten can take a couple more questions...

[ StenOdenwald/Astronomer - 52 - 11:55:17 ]
RE: [SharonRCucamongaCA] Why do stars twinkle?
Because the starlight comes through the atmosphere, and the atmosphere changes very quickly because of air currents at high altitudes. The typical size of this twinkling is about 1/3600 of a degree. Planhets dont twinkle because they are much bigger in size than 1/3600 of a degree, and so their light is steadier than for stars.

[ Sandy/NASAChatHost - 53 - 11:56:04 ]
Space Scientists Online will take a break after this week from chatting. We will resume again in early January. Check our schedule after the holidays and be sure to come back. Sten will resume his twice-monthly chats in January also. HAPPY HOLIDAYS to everyone :-)

[ StenOdenwald/Astronomer - 54 - 11:57:13 ]
Have a merry Christmas and New Year...and with luck, we will all be back here again in the year 2000!