Astronomy [Interview] David Morrison

Discussion in 'Astronomy' started by JcMinJapan, Feb 22, 2005.

  1. JcMinJapan

    JcMinJapan Premium Member

    Ok, the questions and answers are in. I hope that you enjoyed this interview. Please feel free to discuss the topics or anything listed in here below.. Enjoy and thank you soooo much for the people that submitted their questions.

    1. In your opinion is there other Universes, and if so how many would you think?

    No one knows -- other universes if they exist are unobservable. The term "universe" means "everything" -- that is everything that we can know about.

    2. Mr. David, what do you think the effects of "Space ship one" will have on NASA? Is NASA ready to fight the commercialism of space travel? Does NASA have a future in this business, and if so will it be supported by the government?

    It is hard to tell, but I see no basic conflict between NASA's mission and a commercial space effort that provides tourists access to space. I am pleased to see both go forward. The flight of Space Ship 1 was a real triumph, but of course it can only reach the fringes of space, and after a few minutes it returns to Earth.

    3. I thought the sun was a ball of gas with molten mass constantly shifting and molding, therefore how could it have a north and south pole?

    The Sun spins with a period of about a month, and anything that spins has a north and south pole.

    4. If the suns poles shift, wouldn`t that affect the orbit of the solar system?

    No, the Sun's gravity does not depend on its spin.

    5. If the Earths poles shift from a few degrees to 180...could this explain the atmospheric anomolies we have as well as geological shifts, freak storms and the possibile contribution or main factor to global warning?

    No. There has been no major shift in the Earth's spin and none is expected in the future. There is a small continuous shift in the pole, but it amounts to no more than a few meters per year.

    6. Is there any explanation for the rotations of Venus and Uranus in the solar system?

    Both planets probably experienced major collisions during the formation of the solar system that slowed the rotation of Venus and shifted the rotation pole of Uranus. Other giant impacts formed the Earth's Moon and stripped off most of the rocky mantle of Mercury.
    Apparently such collisions were common in the first few million years after the planets formed.

    7. What would you consider your favorite mission that you worked on and why?

    Voyager, which provided us a first good look at so many new worlds, both planets and their satellites, in the outer solar system. The Voyager mission was so exciting because it was the first. The discoveries from Voyager also made possible the subsequent success of the Galileo mission to Jupiter and the Cassini mission to Saturn.

    8. It must have been a great feeling to have an asteroid (2410 Morrison ) named after you and you certainly deserve it, you are actually a person that I truly look up to. What did it feel like when you were told and what does 2410 stand for?"

    It was indeed a great feeling, and especially nice because it happened at the same time that two of my scientific colleagues had their names assigned to asteroids 2409 Chapman and 2411 Zellner. The numbers are assigned chronologically as each asteroid's orbit is determined.

    9. If you were offered a chance to go to any planet of your choice for an exploration project, where would you want to go?

    Mars is the most attractive planet, since it might support indigenous life, and potentially it could also host human colonies. The discovery of lifeforms on Mars with a different origin from those on our planet would be one of the greatest scientific discoveries of all time. Of course, I will never go there personally, but there may be people alive on Earth today who will be privileged to visit Mars.
    Meanwhile, we can all share vicariously in the exploration of the planet by robots.

    10. We hear that there are no known asteroids expected to come close to the earth for many many years. How much of the sky are we actually able to scan and is this based of calculation of averages or are we able to actually see the whole sky?

    The NASA Spaceguard Survey gradually builds up a catalogue of near Earth asteroids, whose orbits can then be projected forward in time to see if any are a threat. The goal is to find 90% of those larger than 1 km by the end of 2008. The Spaceguard telescopes scan about half of the sky each clear night. A few of the asteroids being discovered will pass very close to Earth, but none found so far will hit us (at least not in the next couple of centuries). These statements represent actual orbits of specific objects; they are not statistical projections. For most people, the important thing is not the probability (which is very low) of something hitting, but actual evidence of what asteroid might collide with us and where and when it will hit.

    11. What would be the smallest estimated size of an asteroid that could start long term climate changes?

    It is not clear that any impact could cause a long-term climate change, and there is no evidence that this has happened in the past. The short term effects could be catastrophic, but these effects would last at most a few decades. An impact by an asteroid 2 km in diameter would probably cause an "impact winter" and kill a billion people. An impact by an asteroid 10 km in diameter would probably cause a mass extinction.

    12. I heard that the moon is slowly moving away from the Earth. My >guess is that the rotation of the Earth will slowly change as well as it gets further out. Will this affect our climate?

    The Earth's spin slows very sightly as the Moon moves farther away, but the change is very small, and there is no expectation that this will have any effect on climate.

    13. Does Kepler's Law affect all solar systems or just ours?

    Kelper's Laws of planetary orbits are a direct consequence of gravity, and the laws of gravity are the same everywhere.

    14. I just read about an explosion that originated about 50,000 light-years away and was detected Dec. 27th and it was produced by a magnetar and it actually altered our upper atmosphere a bit. I also read that if this has happened within 10 light years of Earth, that it could have triggered mass exctintions. I also read that there are no known magnetars within that distance, but how much of they sky withing 10 light years have we really mapped?

    Ten light years is considered a very small distance in space, and all the stars have been carefully mapped within this distance (and indeed much further out). Over time scales of tens of millions of years, however, the Sun's stellar neighbors change, so the situation might be different in the distant past or the far future.

    15. I heard that small clouds of dark matter pass through Earth on a regular basis, do we really know what these are and how or even if they impact the earths atmospheric conditions in any way?

    There are no clouds of dark matter that pass through the Earth. The only thing I know of that passes through the Earth are the subatomic particles called neutrinos, which fill space and are able to penetrate an entire planet without being slowed down or stopped.

    16. We had a conversation on IgnoranceDenied a little while back about whether it was possible for NASA to send a man to the moon in a relatively short time. There were many good examples brought up about
    the budgetary restraints on NASA set at a sad rate of around .2% gdp when back in the 60`s it was .8% and the fact the the technology is now outdated. We came to the conclusion that it would not be possible to send a man to the moon relatively soon. Would you consider this to be so?

    What does "relatively soon" mean? And what kind of budget should we expect to be available for this purpose? The current NASA vision calls for a return to the Moon within the next 15 years, but this plan assumes only modest increases in the NASA budget -- far less than the spending levels associated with Apollo program in the 1960s.

    17. What is your stance on Sedna becoming the 10th planet or even taking Pluto out of the classification of a planet all together? Personally, I would not have a problem with removing Pluto and coming up with new standards. I mean if we refuse to change classifications
    >now, won`t that possibly cause further problems once we start getting more data and have to break things down even further?

    I see no problem with keeping Pluto as a planet. Everyone knows it as a planet, so why change? Sedna is smaller, so it also seems reasonable to me that it should not be listed as the tenth planet. It is unlikely that we will discover any other distant objects as large as Pluto. I don't understand why this is such an important issue to some people. Both Pluto and Sedna are fascinating objects to study, whatever they are called.

    18. As the Sun ages, it will get hotter from my understanding. The Earth will slowly move out of the temperate zone of the sun and it will slowly get hotter. I know that this is many thousands or millions of years in the future, but is there any hope to stay on this rock or will we need to abandon the Earth all-together? So, you have any ideas of where we would start to think about?

    You are correct, but the change in solar luminosity is very slow so this is hardly an immediate problem. We have much more important challenges to be concerned with, such as global warming due to changes in our atmosphere. Humans are rapidly increasing the amount of carbon dioxide, which is the primary greenhouse gas in the Earth's atmosphere. The resulting increase in the greenhouse effect is more important for our climate today than changes in the solar luminosity.
     
  2. Bleys

    Bleys Phoenix Takes Flight Staff Member

    :cheers:

    Terrific interview JC!

    I was surprised at this:
    With all that he has been a part of and all that has been learned in the past quarter century - Vger is still his favorite.

    I was also surprised that we have stars well mapped within 10 light years. I thought our understanding of these stars would be very limited.


    Kudos to JC and many thanks to David Morrison for his time.
    Bleys
     
  3. mscbkc070904

    mscbkc070904 Premium Member

    Thanks JC, it shocked me that one of my questions I had was asked, thanks.

    This was the question I had asked or stated:

    5. If the Earths poles shift from a few degrees to 180...could this explain the atmospheric anomolies we have as well as geological shifts, freak storms and the possibile contribution or main factor to global warning?

    No. There has been no major shift in the Earth's spin and none is expected in the future. There is a small continuous shift in the pole, but it amounts to no more than a few meters per year.

    Great Job and hope to see more of these interviews in the future.
     
  4. Tebbo

    Tebbo Member

    Terriffic, not exactly the answer I expected for my question (#2) but the interview is indeed great.
     
  5. JcMinJapan

    JcMinJapan Premium Member

    I am not really suprised by #2 actually. NASA is a science entity. I doubt that any commercial space program will ever send a robot to Mars to check for signs of life, or drop a sattelite in Titan, or send up a spacecraft just to circle Sautrn and Study it. UNLESS... They may have plans to test the atmosphere for breathability, breathtaking photos (For Sale of course) or finding the best spots to setup a hotel, or the best sposts to drill for stuff. If it is economical, then it will happen, but just as a purely scientific study, I doubt that will ever happen, unless for the publicity of it. So... Actually every one wins with commcerial space travel... Why? .... Well, because the commercial side will of course have to invent or develop new technologies to be able to handle their projects. Thus in turn, NASA will be able to use this new found knowledge to its advantage and advancement of the scientific projects. Also, the things NASA develops and discovers will help the commercial firms as well. Thus, hopefully jumpstartinga scientific space boom.

    Win-Win situation all around.
     
  6. DucKid

    DucKid Premium Member

    Very interesting.... awesome interview!
     
  7. sab

    sab Premium Member

    is it just me or are these two answers to these two questions contradictory to each other?



    and



    it seems like to me that turning a planet on its side by a collision will cause a long term effect of climate.
    but then again, im not an expert.
     
  8. JcMinJapan

    JcMinJapan Premium Member

    I think that when he is referring to a major collision in the first one, it is not an asteroid size, but more of like the moon hitting the earth......
    Basically alot larger scale. Basically this would have happened in the initial chaos of in the cration of our solar system before order more or less came into effect.
     
  9. Iceberg

    Iceberg Premium Member

    18. As the Sun ages, it will get hotter from my understanding. The Earth will slowly move out of the temperate zone of the sun and it will slowly get hotter. I know that this is many thousands or millions of years in the future, but is there any hope to stay on this rock or will we need to abandon the Earth all-together? So, you have any ideas of where we would start to think about?

    You are correct, but the change in solar luminosity is very slow so this is hardly an immediate problem. We have much more important challenges to be concerned with, such as global warming due to changes in our atmosphere. Humans are rapidly increasing the amount of carbon dioxide, which is the primary greenhouse gas in the Earth's atmosphere. The resulting increase in the greenhouse effect is more important for our climate today than changes in the solar luminosity.



    I just had a thought - is it possible that life existed on Mars, but then died of because our Sun became hotter as it aged?

    I dont know. I really am new to this stuff.
     
  10. sab

    sab Premium Member


    On 1994 July 16-22, over twenty fragments of comet Shoemaker-Levy 9 collided with the planet Jupiter. and left several scars on juipter several times larger than earth.
    had this comet hit earth, well... i think it would have permantly changed the climate of earth. plus the collision proved that impacts of this nature still happen.


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  11. sab

    sab Premium Member

    plus, he said,

    "Both planets probably experienced major collisions during the formation of the solar system that slowed the rotation of Venus and shifted the rotation pole of Uranus."

    then later said,

    "It is not clear that any impact could cause a long-term climate change, and there is no evidence that this has happened in the past."

    In My opinion, the term "ANY IMPACT" would include any impact and "the past" would IMO include all of history.

    i'm sorry, its early and im just pointing out inconsistencies, i dont mean to offend anyone, however, if i had made statements like that in any of my papers, none of them would pass peer review.
     
  12. JcMinJapan

    JcMinJapan Premium Member

    I am bumping these to find out if you are still interested in getting professional interviews for the site.