Gas giants colliding?

[Stellatus]

What would happen if two Jupiter-like planets were to collide with one another?

I'm talking just, slam right into each other. No close passes first or anything, just bam, like two pool balls knocked into each other. Barring the feasibility of the event, what would happen?

[MKruer]

Its very feasibility, I will go as far as to say it happens all the time. As for what would happen. Both would explode to a point, but the over all mass would be so great a new planet would reform from the debris. Here is the best visual i could find it not great, but if you watch the seconds and third collisions then you should get the idea.

http://www.youtube.com/watch?v=IjsdvOgKvg4

[Chuft-Captain]

Check this one out:

[Chuft-Captain]

I'm not so sure of the accuracy of this video.

At the beginning for example, a person (presumably a scientist) says it's traveling at 20km/s. Later, the narrator tells us it's doing 720,000 km/h.

I think he may have added a zero.
The effects depicted are also somewhat more dire than predicted by: http://www.lpl.arizona.edu/impacteffects/

Perhaps some of the other effects of the video were also inflated for dramatic effect (after all it was made for TV).

I wonder which is more accurate... video or website?

[MKruer]

When the original video came out there was a lot of skepticisms on what would happen. It was originally from a Japanese's show. I think It might be overblown, but then again the visual size is way to large for what was stated.