XRays

[fortytwo]

I've heard that Astronomers believe the gas giants have rocky cores or in lower levels my be liquid, but cannot be sure exactly.<br /><br />Why can't XRays be used to see through gas giants? Are they too dense? (More than me? <img src="/images/icons/tongue.gif" />)

 

[Saiph]

Basically cause they're too dense. First, we can't shine any light at an object and watch the reflection (or see it pass through). We can only see light that is emitted from the objects, or bounced off the objects by other, uncontrolable sources (like a star).<br /><br />As such, if the core of the planet isn't producing X-rays, we'd never see it.<br /><br />Anyway, the planets are dense enough that light will basically be absorbed far before it penetrates even most of the way into (or out of) the planet. So we only see stuff near the outer edges of the gaseous planets. <div class="Discussion_UserSignature"> <p align="center"><font color="#c0c0c0"><br /></font></p><p align="center"><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">--------</font></em></font><font color="#999999"><em><font size="1">----</font></em></font><font color="#666699">SaiphMOD@gmail.com </font><font color="#999999"><em><font size="1">-------------------</font></em></font></p><p><font color="#999999"><em><font size="1">"This is my Timey Wimey Detector.  Goes "bing" when there's stuff.  It also fries eggs at 30 paces, wether you want it to or not actually.  I've learned to stay away from hens: It's not pretty when they blow" -- </font></em></font><font size="1" color="#999999">The Tenth Doctor, "Blink"</font></p> </div>

 

[newtonian]

fortytwo - saiph is correct.<br /><br />To add some depth:<br /><br />Jupiter (in 1991) was thought to have a compact iron-slicate core within a zone of liquid metallic hydrogen with a radius of 45,000 km, then liquid molecular hydrogen some 25,000 km thick, then a hydrogen rich atmosphere some 1,000 km thick.<br /><br />Saturn is similar.<br /><br />This brings up an interesting question -<br /><br />Could our sun have iron in its core, and could this have some effect on its magnetic properties?<br /><br />

 

[vogon13]

Iron's magnetic properties alter significantly at temps above (IIRC) 750 degrees C.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[CalliArcale]

To x-ray an object, you shine x-rays through it and detect them on the other side (either by exposing x-ray sensitive film or with some kind of x-ray detector to produce a video image; the earliest example of the latter is the fluoroscope, which is still in use today). Denser things will allow fewer x-rays to pass through. Your skin barely blocks any, but your bones block a fair percentage, which is why its easy to see your bones on an x-ray image. Metals block a lot more, although with more powerful x-rays (gamma rays) you can get more.<br /><br />So, to x-ray something, you have to pass x-rays through it and pick them up on the other side. Jupiter is a very long ways from Earth. To x-ray it, you'd have to put an x-ray source on the other side, powerful enough to get through a significant amount of this very massive planet (when cosmic x-rays even have a difficult time penetrating the comparatively trivial depth of our atmosphere), and then detect the beam here on Earth. That's just not possible.<br /><br />However, something similar was done once, and only once that I'm aware of. It was a once-in-a-lifetime opportunity. Saturn passed near the Crab Nebula. Amateur astrophotographers had a great time trying to image this event without overexposing Saturn or underexposing the Crab (the trick is to take two different images and combine them). But what was really neat was the fact that, by pure luck, Saturn's largest moon, Titan, would appear to pass right in front of the pulsar at the heart of the Crab Nebula. That pulsar, remnant of a massive supernova in 1054 AD, is one of the more powerful x-ray sources in the sky. The Chandra X-Ray Observatory was used to observe the brief transit of Titan across the Crab Nebula, and especially the short eclipse of the pulsar. It provided a unique opportunity to study Titan's atmosphere, and the data is still being analyzed (and probably will be for decades, as it can be compared with other data still being gathered about <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[jeepmonkey]

"Could our sun have iron in its core, and could this have some effect on its magnetic properties? "<br /><br />I believe the sun is large enough to have atoms heavier than Hydrogen and Helium at its core, but would the etremely high temperatures keep atoms heavier than Hydrogen and Helium from forming?<br /><br /><br /><br />

 

[vogon13]

BTW, extremely high temperatures cause helium to form heavier elements.<br /><br />Up to around iron in fact.<br /><br />As temperatures increase above that toasty level, the iron will decompose, absorb energy, and if the star is massive enough, trigger a supernova.<br /><br />The supernova will zap the materials strongly enough to form elements more complex than iron.<br /><br /><img src="/images/icons/smile.gif" /><br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>