In light of the events of the past few weeks in this region of the country we have been somewhat behind the curve of events and news going on in the world of astronomy and space science. But things have settled from the aftermath of hurricane Ike and we have a few late editions to the September newsletter. Astronomers have found something they are calling a “dark flow” that may indicate things beyond the observable universe, astronomers were able to observe an extra-solar system that they believe harbored a colossal planetary collision, and solar energy output is declining and currently at a fifty year low and an announcement of a talk that is on space weather…..so lets get into it.
The “Dark Flow”:
There is now another “dark” mystery in the world of cosmology and this “dark flow” is no less alluring than the other dark topics for anyone with even just a casual interest in astronomy and cosmology. This most recent edition to the grand mysteries is being called the “dark flow” because observations of massive galaxy clusters show that they are all, and uniformly no less, moving toward something that lies outside the observable universe, and so with no hope of us ever seeing this something, it is now called dark. The discovery was made using data from the WMAP space craft that observed and imaged the cosmic microwave background radiation (or CMB for short) which is a flash of light that was emitted when the universe was only 380,000 years old (I say only because in comparison to the current estimated age of the cosmos, 13.7 billion years, it is a small number) and the universe was first transparent to light. This image shows the ultimate reference frame for motion in the universe, for there should be no preferred direction of motion relative to the CMB, but this latest research result shows different. The team from the Goddard Space Flight Center looked at  | Seen here is the CMB. The purple circle is
is the patch of sky toward which the observed
motion is directed.
Credit: NASA/WMAP/A.Kashlinsky et al. |
hundreds of galaxy clusters in nearly half of the observable universe and determined that they all show motion of about 2 million miles per hour toward a patch of sky that is between the Vela and Centaurus constellations and is about 20 degrees across. The motion has the curious characteristic of being uniform out at least to a billion light years and it most likely “extends across the visible universe” says Kashlinsky, the lead researcher on the project, and the reason this is curious is because according to standard cosmological models motion should decrease with distance, so whatever is attracting these super clusters is strange indeed and except for theoretical insights no one really has any valid idea of what it could be, hence the “dark”. Whatever the attractor is it lays outside the observable universe and that isn’t just what we can see with a telescope, it is all we can see even with a telescope, for the observable universe marked by the distance light has traveled since the big bang, since light has a finite speed there is only a finite distance that the observable universe can be. Now some cosmological theories, including inflationary theories, tell us that the universe is much larger that just our observable region and what is outside of it could be either very similar to our part of the cosmos or it could very well be different in startling ways, with totally different physical laws. These other regions of space-time may have a totally different density pattern of matter, making the region devoid of the stars and galaxies that we find in our own, this strange and far distant region might contain structures larger and more massive than anything known in our region of space-time, and it is this that may be causing the observed bulk cluster motion. Whatever it is and wherever it is, it obviously isn’t immune to gravity and is pulling the most massive structures in our region toward an unknown and mysterious place. This discovery is a great example of how progress is made in science, for this was something that no one was looking for outright and that no one even expected to find and that is often the way science works. There will be more and more research done on this of course and the gravitas of this find, forgive the pun, can not be over looked. For more information on this story visit the NASA release, one of our original sources;
http://www.nasa.gov/centers/goddard/news/topstory/2008/dark_flow.html
To read preprints of the actual paper scroll to the bottom of the NASA news release and click on the link to view a PDF. Collision of the Planets; they think…..
BD+20 307 may not sound like anything more than just a catalog number given to something all the more average for it, but this is the name given to a star that harbors something far from average. A team of astronomers from UCLA, Tennessee State University and the California Institute of Technology discovered a dense ring of warm dust around this star and had believed it to be a proto-planetary disk, such as would be found around a relatively young star that was in the process of forming planets, but to their surprise the star in question was far older than previously thought and much to old to still have such a proto-planetary dust ring, so what happened to give such a star this ring? Well the team is saying that the ring of dust is most likely from a massive planetary collision between two well formed bodies in the interior of this extra-solar system and such an occurrence is  | An artist rendering of what a collision of
how a collision of planets might appear.
Credit: Lynette R. Cook, for Gemini Observ-
atory. |
believed to be a relatively rare thing to happen in such a well formed and presumably stabilized system. Other astronomers were asked to look at the star and provide more data on it and they then found that the star was actually a pair; a binary system with stars very much like our own sun, and this made the discovery all the more interesting of course. When the dust was looked at closely they found that there was over 1 million times the amount of dust that we currently find in our own solar system and this, they say, is indicative of a collision of two bodies of around Earth or Venus mass colliding. Though far removed in space from our own position and perspective it is not hard to imagine such a colossal event as that, and it brings to mind the conditions on those exo-planets involved, for if there was any life on either of the impactors than it is surely no longer, for if Venus collided with Earth the devastation would be…..well…..total. The event occurred, most likely, in the past few hundred thousand years or possibly sooner and if nothing else it serves to remind us of the fragility of our own precarious position in the cosmos, for nothing is immune to the ravages of time.
For more information on this visit the original press release and our original source;http://www.newsroom.ucla.edu/portal/ucla/worlds-in-collision-astronomers-63891.aspx Solar energy at, at least, fifty year low:
We humans have been keeping track of the solar wind pressure since the beginning of the space age, and new data from a joint NASA-ESA mission, Ulysses, is showing that the solar pressure is the lowest it’s been since we began keeping records. The solar wind rushes away from the Sun at around one million miles per hour and creates a protective bubble around the solar system. Called the heliosphere the bubble extends far beyond the outer planets and influences everything in the solar system, it is really the extended atmosphere of the Sun. The boundary between the influence of  | A rendering of our solar system showing
the heliosheath and heliosphere, as well as
the two voyager craft.
Credit: NASA/Walt Feimer |
the Sun and interstellar space is marked by what is called the heliopause, this is where the solar wind slows to a point where it can no longer push out the external pressure. The heliopause and the region immediate to it helps shield our system from particles zooming around interstellar space, called cosmic rays, they carry radiation from other parts of the galaxy and some are even thought to be of extra-galactic origin. Though the lower output of the solar wind is curious, it isn’t time to start worrying, we know that the Sun has regular cycles and this could be one that is more prolonged and seeing as though our records only go back a tiny portion of the Sun’s lifetime it more than likely is. None the less it is of incredible importance to understand our star since we do find ourselves inside its atmosphere and tend to favor its warmth to the unending coldness of space. The research will help, in time, shed light on this issue of the lower pressure and until such point we will just have to hope that it doesn’t go all too low.
For more information on this story visit the following link and our original source;
http://science.nasa.gov/headlines/y2008/23sep_solarwind.htm
As an adjoining announcement there is a talk going on at Rice University here in Houston entitled; "SUNSPOTS: Connecting the Solar Interior to Space Weather" given by David Alexander of Rice University. The talk will be held in 210 Herzstein Hall at the Rice University campus and will be from 4:00-5:00pm on Wednesday, October 1st. The talks given there are always well worth the time. For more information on this talk or others visit the Rice University webpage; http://www.rice.edu/ |
