2009-10-19

TESB Docking Bay Asteroid

For years, pro-Wars debaters have argued that there is a scene of a ~10 meter asteroid striking the shields/hull of an Imperial Star Destroyer.  This asteroid, which we will call the Docking Bay Asteroid for ease of identification, is claimed to hit a spot just to the portside of the ISD's lower docking bay.  



As a rule of thumb, the basic claims went uncontested.  Everyone could
see an asteroid, a flash, a lack of asteroid, and the ISD continuing
on.   Certain low-resolution reviews seemed to show something extra in
the area at the time of impact, but it was never conclusive.

The claim has existed for years and is generally used in arguments about the shield capabilities of Star Destroyers.   For example, we have Curtis Saxton at TheForce.Net:
"A similar collision between another destroyer and a smaller asteroid left the ship unscathed. The asteroid struck near on the portside of the primary docking bay. Upon impacting with the shields it crumbled within a fraction of a second, indicating a lower-limit estimate on the shields' capacity to absorb sudden blows. The asteroid was approximately 10m in diameter and had a kinetic energy of at least 2 x 10^12 J. "
That is a kinetic energy of about half a kiloton, and has been claimed as a universal lower limit for the shield capacity . . . or occasionally the capabilities of the armor . . . of Star Destroyers, based on the rather convenient fact that at such a long range no damage was apparent.

Of course, unsatisfied with that value, others have claimed that the small and distant asteroid was vaporized by the shields, thereby extending the utility of the most convenient fact that the object was so distant debris would never be observable.   Presumably using vaporization calculations against the 10m potato-shaped asteroid, the shields are thus said to have imparted four kilotons of energy on the asteroid.

With the advent of the HD (1080) broadcasts of the films, however, all the claims can be laid to rest at long last.













The asteroid, moving up the screen at a nice clip, does indeed seem to explode in a flash.  However, that flash begins at the bottom of the asteroid.   Can't see it?  Let's zoom pics 1 and 3:





And here we'll show the two frames overlaid at half opacity, with the top of the asteroid in about the same spot in both shots:



Last but not least, we have the animated .gif:



And so with the facts obvious, we may clearly note that the top of the asteroid is still visible while the bottom is flashing in an explosion.  This is grossly inconsistent with the notion of a shield impact.   For an impact, the initial forces and damage would naturally occur against the "front" of the asteroid relative to the ISD . . . e.g. the impacting side.   Oh sure, we can imagine an event similar to Newton's Cradle wherein the collision shockwave travels through the asteroid leaving the front completely unperturbed but blowing out the tail of the asteroid somehow, and I'm sure my opponents will plant their standard on such an unlikely event.  However, the conclusion that this is not an impact is simply obvious and obviously simple.

"Ah," some might claim, "but the asteroid continued to move between your frames 1 and 3, which is why you had to move the top of the asteroid to match in the overlay.  So even if you're right, this means that the Star Destroyer must've shot at and vaporized a ten meter asteroid, because otherwise the mass would still have hit the shields anyway!  Thus we still have a four kiloton shot!"

This, however, is wrong-headed.  The scaling of the asteroid (from which the firepower would be calculated) is entirely dependent on the assumption of contact or near-contact with the hull.   Without that, we have no idea of the size of this asteroid, because we don't even have a turbolaser bolt to measure against.  We cannot even reliably claim that the asteroid was headed for the ISD, given the other ISD shots in the scene fired against non-threatening asteroids.

As such, we know almost nothing about this asteroid, except that it is seen to explode from the bottom up.  This tells us it was not a collision incident, but little else.

At best, one can simply claim that this is one of the more accurate shots ever seen from an ISD, one which happens to involve a bolt or other weapon shot that the camera is at the wrong angle or too great a distance to observe.

(Or, out-of-universe, it's a simple VFX error of a forgotten bolt.)


2 comments:

Ilithi Dragon said...

Interesting... I never even considered that to be an impact with the ISD at all; the angle and direction, etc. all seemed wrong, and it just looked much closer to the camera than the ISD.

Anonymous said...

WAIT A MINUTE!
Lemme get this straight.

This asteroid hits the ship's shields, and makes that feeble-assed little "flash--" barely more than the death-throes of a half-dead firefly-- and the Warsies claim that's the equivalent energy of 500 TONS OF TNT detonated there?!!!!!

Just asking.

Yeah, I'd say that's about their usual level of unreality-- according to them, entire universes can be destroyed by one of Yoda's farts.