Comet Photos

mellestad
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Atheistextremist
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Yeah I had a wow

 

moment when I saw this shot. I think in the show Planets they talk about comets and rocks and so forth crashing together over billions of years to form planets and seeing this active little monkey with H20 squirting out of it was a verification of some mental imagery. It's not just an inert object. It's a contributor. And how cool for the bloke who discovered it through a telescope to now see it close up.

"Experiments are the only means of knowledge at our disposal. The rest is poetry, imagination." Max Planck


XaosPeru
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Atheistextremist

Atheistextremist wrote:

 

moment when I saw this shot. I think in the show Planets they talk about comets and rocks and so forth crashing together over billions of years to form planets and seeing this active little monkey with H20 squirting out of it was a verification of some mental imagery. It's not just an inert object. It's a contributor. And how cool for the bloke who discovered it through a telescope to now see it close up.

It's an interesting theory, but not everyone agrees with that theory of comets.

Quoting from http://www.lewrockwell.com/orig9/hogan5.1.1.html

A good illustrative example, and one not too far from home, is the case for comets, which describe highly elongated orbits about the Sun, lighting up to produce their familiar, spectacularly glowing "tails" during the period of close approach, and then vanishing back into the depths of space for many years before reappearing. The conventional model holds them to be loosely aggregated "dirty snowballs" of primordial matter left over from the time of the Solar System's formation, scattered as a cloud about its distant environs like debris around a construction site. Supposedly, occasional disturbances, for example by a close-passing star, would perturb some of the bodies making up the cloud toward the Sun on paths that became orbits. At the inner extremes of these orbits, the Sun's heat causes sublimation of the ice and release of trapped dust and gases, which shine in reflected sunlight as an extended "coma" surrounding the comet nucleus, and which the pressure of radiation and the solar particle "wind" shape into an enormous fan directed away from the Sun. However, several space missions dispatched to test the model have returned results so much at odds with it that even proponents are admitting that they are going to have to rethink just about everything they thought they knew.

The standard explanation of comets has always had difficulties that many have felt make the model less than satisfactory. But if one is committed a-priori to a doctrine of everything in the Solar System being formed together by accretion from a contracting cloud of dust and gas billions of years ago, it's really the only game in town. How, for example, does a tiny nucleus measuring typically a few kilometers across manage to hold together and entrain a coma that can be millions of kilometers long, and beyond that an even larger tail that exhibits a structure of filaments and pencils?

If comas form from expanding gases and dust released by the Sun's heat, why are they seen in the outer reaches of the Solar System where the Sun's influence is negligible, as happened when Comet Halley was observed to flare up spectacularly in 1991 between the orbits of Saturn and Uranus, or Comet Holmes 17P in 2007, which underwent a millionfold increase in brightness when it was heading away from the Sun? Even more astonishing, how does a glowing coma sometimes manage to emit X-rays as intense as those measured coming from the Sun, as Comet Hyakutake did in 1996? Nothing in a comet is supposed to be energetic enough to produce X-rays.

And then at the other extreme, if the nuclei are rubble held together by ice, how do they remain intact through the heat encountered in the close passes made by the class of comets known as "sungrazers"? And if comets are cold, dead objects enlivened only by surface action of the Sun, how can they release material as energetic jets reaching over huge distances, and undergo explosive fragmentation? Answers to all these questions have been proposed, but always after the event to account for "anomalies" and "surprises," never predictively, and seemingly becoming more strained and farfetched, with a feel about them of defending a reigning paradigm whose core assumptions can't be questioned. However, recent findings from actual close-up comet encounters seem to put the theory beyond rescue....

 

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"The church at the time of Galileo was much more faithful to reason than Galileo himself, and also took into consideration the ethical and social consequences of Galileo's doctrine. Its verdict against Galileo was rational and just, and revisionism can be legitimized solely for motives of political opportunism." -Paul Feyerabend

"Let me just anticipate that nobody to date has found a demarcation criteria according to which Darwin can be described as scientific, but this is exactly what we are looking for." -Imre Lakatos