"We didn't expect the success of one part of the mission (bright dust cloud) to affect a second part (seeing the resultant crater). But that is part of the fun of science, to meet with the unexpected. "

 

Physicist Wal Thornhill commenting:

"It is now well documented that every scientist associated with the project was stunned by the scale of the energetic outburst. These scientists understood the kinetics of impact, and they all agreed that the explosion would be equivalent to 4.8 tons of TNT. That’s a good-sized bomb, but not even close to what occurred."

"Since the visible images have a higher spatial resolution, we use those images to calculate the extent of ice on Tempel 1's surface. That turns out to be a small fraction of the surface, only 0.5%. "

"What is significant is that the extent of this ice on Tempel 1's surface is not sufficient to produce the observed abundance of water and its by-products in the comet's coma. "

A few more quotes from the Deep Impact scientists commenting on the impact event data:

"Theories about the volatile layers (water ice) below the surface of short-period comets are going to have to be revised"

 

"All we needed was a factor of three boost from the impact to get a definite detection," said Qi. "We didn't see that."

 

"It's pretty clear that this event did not produce a gusher," said SWAS principal investigator Gary Melnick of the Harvard-Smithsonian Center for Astrophysics (CfA). "The more optimistic predictions for water output from the impact haven't materialized, at least not yet."

Some more: 

"There's a lot of structure on the comet, which is a bit surprising," Richardson said. "That could mean there's some strength to the comet."

 

Here is a picture of the actual impact.  I want you to keep in mind that the 850 lbs copper impactor that is striking the comet is basically an invisible spec in these images.  It's so tiny against the huge comet that you can't even see it.  As one scientist put it, "Its like a mosquito hitting a 747."  The nucleus is estimated to be about 5 kilometers (3.1 miles) across and 7 (4.3 miles) kilometers tall.  The detonation of the impactor is tremendous.  Far greater than any model predicted (well not exactly... the electric model predicted it correctly).  The impact event actually created a double flash.  Two explosions took place; again, something correctly PREDICTED by the electric comet theorists.  In fact all of the above observations were correctly PREDICTED by electric comet theorists.  The double flash was created by an electrical discharge between the copper impactor and the comet, then the impact itself produced a flash.

 

 NASA/UM M. F. A'Hearn et al., Science 310, 258 (2005)

 

In 2004 the Stardust mission sent a probe to collect dust samples from comet Wild 2.  The dust samples that came back showed organic compounds that must have formed in EXTREME heat.  No plausible explaination exists in the standard model of comets for how these particles ended up in the coldest and oldest places in our solar system.  It is important to note, that such particles are a by-product of electric discharge machining with plasmas.  So while the standard theory of comets has no ready explaination for the findings, the electric model of comets predicted this.

 

Other comets have also displayed intense brightening at distances too far from the sun to be attributed to melting and a host of other phenomina not explainable by sublimation such as xray emission and filamented tails.   Here's a perfect example of filamentation that is completely unexplainable in the standard model.

Comet C/2007 N3 Lulin (negative luminance) - J. Brimacombe

"Past efforts with the near-IR spectrometer on Deep Space 1 mission flying past comet Borrelly and from the ground of comets far from the sun and not enshrouded with coma, have yielded no evidence of water ice on their surface." 

A space telescope that usually studies the most powerful explosions in the universe has set its sights on an approaching comet. Its observations at ultraviolet and X-ray wavelengths should help reveal the comet's composition and 3D structure.

"Like people, all comets are a little different. We've been studying comets for hundreds of years -- 116 years in the case of comet Holmes -- but still do not really understand them"  

M. J. Bosler, "Sur les variations d'éclat de la comète d'Encke et la période des taches solaires"(1909) Comptes rendus hebdomadaires des séances de l'Académie des sciences, 1909 (T. 148). Chart: page 1740

Top curve, dotted: Comet brightness

Bottom curve, solid: Number of sunspots.