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NASA Discovers A Ring Around The Solar System (npr.org)
41 points by epi0Bauqu on Oct 20, 2009 | hide | past | favorite | 15 comments



Why do the images from IBEX take 6 months to be composed?


AFAIK the IBEX isn't a photographic telescope, it develops its images through energetic neutral atoms and not photons. It takes over 10 hours for light to get from the sun to the heliosphere, so to retrieve particles that are travelling at sub-light velocities and are moving into the solar wind must take considerable time alone, and then it requires building an image from the particle densities retrieved.

Simply put, unless you ask a NASA scientist exactly how and why, the answer is and likely always will be; it just does.


You don't retrieve those particles; an admittedly absurd extension of your reasoning would imply that it takes 200 million years to image a quasar, because that's how long it takes to retrieve the photons that form your image.

What we're seeing here is both faint and enormous. Both characteristics make it hard to detect, and it isn't bright enough to capture without a long exposure, plus you can't look at it during the day, and you can't see the side beyond the sun... all characteristics that lead to longer imaging times.


Low-level signal = long exposure time


Doesn't this make anyone else wonder about the accuracy of statements physisicts make about other galaxies? I mean, it seems to me like if we're still disocvering things like this about our solar system (relatively nearby) then how in the world can anyone be confident about statements made about other galaxies (compratively further off)?

To some degree, I'm sure its just the fact that articles written for non-scientests tend to make them sound more sure than they are, but it still seems strange to me...


Not really. They hadn't put this data together before. Now they did, and they found the ring. The conclusions about other galaxies are also based on data. It's not like anyone had previously said that there is no such ring around the solar system, the data just wasn't there.


Sure, but I guess my point is that we had only indirect data about the fringe of our solar system before, and now that we have more direct data (i.e. actually sending a satellite out there) we discover something pretty big. The data we have about further away galaxies is even more indirect and the light we get from them is subject to any number of possible phenomena we may not have accounted for. The level of confidence about the conclusions we draw though seems way to high given that its clear there are phenomena we don't know about.


Causes a human to wonder how these protective stellar bubbles' interactions with the galactic environment affect the development of (possible) life in star systems.


Remnants of our solar accretion disk?


The stripe is perpendicular to the direction of the magnetic field of the galaxy and not in line with the ecliptic plane. The interview I heard here (http://ww.npr.org/templates/transcript/transcript.php?storyI...) suggests that the hydrogen that makes up the stripe is being continuously accumulated, not leftover from old times.


If it's perpendicular to the solar systems trajectory, then it could potentially be an aerodynamics issue not taken into account.

AFAIK the solar system is moving at essentially supersonic speeds through the solar medium, which causes the bowshock, so couldn't this just be an eddy current we've been unable to distinguish either because it's not present in smaller scales, or simply because it's normally small enough to be a statistical anomaly?

The physics of our solar systems action are essentially similar to small body physics, the problem is that they're blown up on scale unimaginable to us. Essentially our comparison of physics is akin to comparing getting up to turn the tv on with a trip to Alpha Centauri and back.


Ummmmm... There is almost no air in space, which causes there to be no sound in space. Therefore, the ability to go 'supersonic' in space is highly overrated, seeing as sound simply doesn't even try. This all leads me to believe there's probably not bowshock either.


You're right that there isn't much air in space, but bowshock isn't specific to "air". There most definitely is bowshock in space: http://en.wikipedia.org/wiki/Bow_shock


The person mentioned supersonic, so I figured that's what the bow wave was referring to. Doesn't help that I work in aircraft and haven't been keeping up on my space knowledge lately ;) (And I don't work on cool military supersonic things, so my supersonic is rusty too...)

I still maintain you can't do do supersonic things in space. The would imply sound moves in space.


In other news, women now find the solar system 10% more attractive.




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