Tags: Kepler, Nasa, overview effect, time travel
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The Kepler space telescope is trailing Earth in its orbit, and has begun scanning its small patch of sky for twinkling stars. It will be a long time before the telescope finds any extra-solar planets, because it relies on planets crossing between Kepler and their stars, causing the stars to dim. To ensure it really is a planet and not some other phenomenon or glitch, it has to watch for several regular transitions. Of course, each planet will cross its star once a year, so these periodic dimmings are few and far between. This means it will be years before the existence of extra-solar planets is confirmed. In other words, the sooner we get started the better. See my previous blog post with professor Mike Thompson for more information.
The new Star Trek movie apparently has some time travel in it. I haven’t seen it yet, and am generally wary of movies that use time travel as a plot device. However, there is a very interesting article about some of the false presumptions of time travel at the Discover website. The article answers a lot of questions that I’d had, and things that I’d puzzled over. Check it out!
Here‘s a good article about one man’s plans to examine the Overview Effect, the feeling of oneness that astronauts get when seeing the Earth from space. Apparently, this happens pretty regularly. I heard one Apollo astronaut (I forget which one) mention the feeling in the terrific documentary In the Shadow of the Moon, but I didn’t know it was such a common phenomenon.
Finally, you’ve got to see this slideshow on the National Geographic website featuring glow-in-the-dark animals.
Tags: Astronomy, astroseismology, coronal mass ejection, helioseismology, Kepler, Nasa
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There has been a lot of talk about the Kepler space telescope and its mission to find Earth-like planets outside the solar system. Its lesser-known but perhaps more important mission, however, is to collect information about the internal sonic vibrations of stars (expressed as small, periodic variations in emitted light) in order to learn about their evolution and structure.
I interviewed Professor Mike Thompson of the University of Sheffield, who will be analysing the information sent back by Kepler for this purpose.
Mike Thompson is a professor of applied mathematics and solar physics, and head of the school of mathematics and statistics at Sheffield University. He studies astroseismology and helioseismology, in other words the vibrations of a star. He also studies solar physics, stellar structure and evolution, and astrophysical fluid dynamics.
Can you tell me about what you are doing for this mission?
My own scientific interest actually is in terms of the stars themselves rather than the planets that are going around them. I use a technique called astroseismology. Many stars oscillate because of the presence of sound waves that are travelling inside them. These sound waves, if they have the right frequency and wavelength, will actually set up certain resonant oscillations of the star. We measure these frequencies at which stars vibrate by making careful observations of the variations of their light. We can use those frequencies, combining many of them, to measure how temperature varies inside the star, what its composition is, even how fast it’s rotating inside.
A good analogy would be of an organ pipe. And organ pipe of a given length will only sound certain notes. If you measured the frequency of those notes or listened to them you would be able to tell something about the structure of that organ pipe. How long it is or what it’s made of, combined with something about the composition of the gas inside it or the composition of the gas. We’re doing similar things with stars.
What sort of practical applications could we see coming from the information that you’re going to analyze?
I think the main practical benefit of learning about stars is what it tells us about our own sun. One of the things we want to understand better is how the magnetic activity cycles work. So in the case of the sun the magnetic activity cycle manifests itself as a sunspot cycle and that’s connected with highly energetic and potentially damaging explosive events (such as flares and coronal mass ejections). These things come out in ways we don’t fully understand and can’t yet predict at the earth and can have serious impacts on our technological society, on communications satellites, on our power grids and so on.
Are there health implications for these coronal mass ejections?
Yes, there certainly are. If an astronaut is in space when one of these things goes off then they could get seriously fried. People have looked at the occurrence of these against the times when the manned Apollo missions were up in space. The Apollo astronauts were quite fortunate. There were some big explosive events that went on and very fortunately there were no Apollo missions up there at the time. But if we want to send manned missions to Mars which of course is now being talked about, then those astronauts are going to be in space for a considerable period of time.
At the moment one of the very big concerns for those of us who study solar variability is the high likelihood that there would be events that would happen during that time which would actually be fatal to the astronauts involved. So how do you develop technologies, perhaps using magnetic fields around the spacecraft, to protect humans in space?
An artificial magnetosphere would actually deflect these particles away. The alternative would be to have large amounts of lead around you, but of course the expense of getting that mass into space is absolutely prohibitive.
How often do these coronal mass ejections occur?
They happen quite frequently. At the height of the solar cycle there could be one a day of these going off, but most of them aren’t coming towards us. But occasionally you get one of these guys and it comes in full face on at the earth, and then it shakes the Earth’s magnetosphere and causes interesting and very exciting aurora displays. They can knock out power lines.
These coronal mass ejections will take a few days to get from the sun to the Earth, whereas light takes eight minutes. Nonetheless, you don’t get much warning. So, better understanding of the sun, better understanding of what the precursors are for predicting these things would be very valuable.
That’s all for today. He gave me some interesting info about Kepler which I will save for a later post.
Purely by coincidence, New Scientist had an alarming article about the disastrous potential consequences of coronal mass ejections in this week’s issue. Read about it here, with an interesting comment here.
Also, take a look at these amazing robot fish!
Facebook warning and Hubble/Kepler update February 18, 2009Posted by Mike Trudeau in Space, Technology, The Internet.
Tags: copyright, Facebook, Hubble, Kepler, satellite collision, space junk
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Before anything else, I recommend you go into your Facebook account and change your privacy settings. here is an article about Facebook’s recent changes to its terms of service (that thing you say you’ve read and understand before you get your account) that supposedly means Facebook permanently owns all the rights to your photos and notes etc. Here is Facebook’s reply, that claims no such thing. I still changed my privacy settings and you should too.
I came across this diagram to give you the idea of how much space junk is orbiting at what altitude, along with other functioning space objects like the Hubble. The accompanying article raises the point that even if there is no direct threat of debris hitting the Hubble or the ISS, there is still the risk that clouds of debris produced by the recent collision could prevent the upcoming Service Mission 4, scheduled for May 12 2009. The aim of the mission is to repair several of the telescope’s systems and install some new hardware that would hugely increase its abilities. Without this mission there would not be a lot of hope left for Hubble’s continuing operation.
Speaking of space telescopes, the BBC ran an article describing how the Kepler Space Telescope will work. I had no idea that the area of sky visible to the Hubble is only as much as would be covered by a grain of sand held at arm’s length! That’s tiny! In comparison, Kepler will be able to look at an area about the size of your hand at arm’s length. Also, its cameras are much more powerful.
The article says we can hope to see our first results within three months or so of launch, but that finding an Earth-sized planet will probably take several years. Now I know everything space-mission-oriented takes a long time, but I’m also very impatient…
The telescope is named after the father of celestial mechanics, Johannes Kepler. Basically he discovered a lot about planetary motion, which is captured in these beautiful and intricate mechanisms called orreries. Check’em out!
Liftoff February 16, 2009Posted by Mike Trudeau in Space.
Tags: Comet, Kepler, Lulin, Mark Henderson, Nasa, Virgin Galactic
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The first post is the hardest, I hope. I’ve definitely deleted about a post’s worth of first few words.
There are are two things happening in the sky in the next few weeks. First, the comet Lulin will be swinging by with incredible speed. She’s travelling in the opposite direction around the Sun from the Earth, so she’ll be moving very fast from our perspective.
Her path suggests that this is her first time through the inner solar system. It’s nice to see some fresh faces every once in a while.
Lulin will be closest to the Earth on February 24. Maybe some other Sheffield residents would like to head out to the Peaks for a peek?
Here’s a good article about it.
Also, woot woot! Let’s hear it for the launch of the Kepler Mission! Although we have recently seen a spate of planets discovered outside our solar system, they have mostly been gas giants and “super-earths” orbiting so close to the sun that chances of supporting life are pretty grim. However, Kepler will be able to see smaller planets orbiting further from their stars, and hopefully begin to catalogue the hundreds of billions of earth-like planets that exist in our galaxy.
Kepler will launch on March 5th at the earliest. You can see the official countdown clock here.
I have to give the Times the award for overstatement with their headline “‘Trillions’ of Planets May Be Supporting Life” on February 16th. The small print is that this number is the estimated number of Earth-like planets in the galaxy multiplied by the estimated number of galaxies in the universe. Maybe I should remind Mark Henderson that given the still not-disproven theory of parallel or multiple universes, there could be up to an infinite number of Earth-likes out there. If he wanted to pump up the headline a little more maybe he should just say that there may be a gazillion-kajillion planets capable of supporting life.
Ah, I’m too harsh. It’s a good article.
I could be preaching to the converted here, as we’ve all heard the argument that there are so many stars and so many planets that there must be inhabitable or inhabitted worlds out there. It’s just nice to see some quantification.
Finally, the idea that we soon may be able to do this blows my mind a little bit. Check out the ingenius wing mechanism that prevents us from burning up during reentry. Beautiful!