It's okay, shooting your ashes into space........ it fits here.

Technically, Spock's death occurred as a result of radiation exposure when he went into the reactor area and fixed the problem they were having going to warp just in the nick of time so they didn't all end up being used as building material for Genesis' new matrix, but I know what you meant.

And, yeah, that whole "Search for Spock" pretext was pretty weak. The only thing that made any sense whatsoever, (in a sci fi stetchy sorta way), was that, once on the planet, (and I believe the movie shows the torpedo being launched towards the new planet), the Genesis effect brought him back.

But a new world from a nebula? Well, ok, if there was enough matter in the nebula, I suppose your could build yourself a planet.

The whole idea of the Genesis Device was to find a lifeless world in a star system, presumably the correct distance from the star to provide earth like heat and light, then touch off the device and it would used materials from the world to create life, and "voila!" Pretty sure the planet was even supposed to already have its own atmosphere already in place, though they may not have come out and said it. But, all of a sudden, the device was capable of not only creating an atmosphere, but the planet itself!

But when they were fighting Khan and company in "Wrath of Khan," they weren't in a solar system, they were warping through space and ended up in a nebula. So, where's the sun around which this new planet revolves, or, without a sun, where did all the light come from and the heat, so as to keep all this new evolving life, including Spock, the Klingon landing party, Kirk's landing party, etc, from freezing to death?

No explanations that I could remember, just a "brave new world," presumably miraculously having found a star, "established standard orbit" around it at just the right distance to keep things alive and well.

Heck, at least they could've shown the new planet right after it was formed and they had shot spock onto it going to warp in the direction a nearby star system - and mentioned it as an "undocumented feature" of the Genesis Effect!!!

This is a question I have had for years.

They are out in the middle of nowhere. Space station Regula 1 was in orbit of an asteroid, but I never saw any evidence of a sun. However, I suppose it is possible that Regula 1 was in a solar system. The "1" may indicate there was more in the area, like a 2 and a 3.

They couldn't warp away, so they headed for the nebula.

But, in the asteroid where they performed the Genesis test, there was a light source back in the cave that made it appear their was a sun inside the cave. Never understood that.

When Spock's torpedo was shot at the planet, it made for a nice moment to have the sun rise at the same time.

OK, Search for Spock. Yes, Sarek asked Kirk to bring his son home, along with what was left of his marbles rolling around in McCoy's head, but what did they really expect to find back at the Genesis planet? If they shot the torpedo at the planet, then they should have expected that it just burned up in the atmosphere.

They didn't know that the gravity was in flux, allowing the pod to soft land.

Oh, well. It was a good movie anyway.

Let me take a crack at this (to play devil's advocate for the writers)...

Well, we don't know just how big the Mutara Nebula was--it may have been the size of the Sol System (or bigger), as far as we know. If the Mutara Nebula was perhaps a star system that failed came into being, the explosion of the Genesis Device might have triggered the final process to create a star and a life-supporting planet.

After all, our very own Jupiter could have become another star had it just had more mass to ignite its hydrogen atmosphere. Had that happened, we would probably be in a binary star system with perhaps several of Jupiter's moons possibily being planets able to support Human (or Humanoid life).

One thing to bear in mind, though, is that Genesis was ultimately a failure. Its effects and results were discovered to be temporary. Even if the Genesis Experiment was conducted under the original ideal conditions, the results would have--eventually--been the same. Doctor David Marcus admitted to the unethical use of protomatter in Star Trek III which wound up aging the planet too fast.

Sooooo, now the Genesis Effect, which started out as an incredibly powerful, planetary wide effect when first viewed by Kirk, Spock, and Mc Coy on the Enterprise, and had the ability to generate life on a lifeless planet, (albeit, a planet already in orbit around a star at an appropriate distance and presumably with an atmosphere)...

...still with me...

...NOW becomes an effect of solar system system wide proportions, triggering, not just life, but the creation of an entire planet, its atmosphere, a star, and the established orbit of said planet around said star at the right distance to sustain life...

...still with me...

...Good! I like it! Not sure I like it any better than the "undocumented feature" of being able to warp the entire planet over to a star system and establishing "standard orbit," around the star, but I like it!

Hey, the movie was cool, this is Trek, and we forgive 'em!

Mighta' been interesting if they'd done a small number on the idea that Khan becoming part of the "new life matrix" was an "evil element" introduced into the "Garden of Eden", especially since he loved playing the part of Satan so much, but, hey, I think the writers figured they had asked enough of us already in the suspended belief department.

Of course, the odds of such a device turning a nebula into a star and a life-supporting satellite in a matter of minutes or hours is too astronomical to begin with, but we are dealing with the Genesis Device--which may have been condemned after Star Trek IV for being man's attempt to play God...

All evidence in Star Trek II points out that the detonation of Genesis within the Mutara Nebula was totally an accident, and the formation of the Genesis planetary system unexpected. The Genesis planet was doomed to failure, IMO, because not only wasn't it created under ideal conditions, but because the experiment itself was doomed because of the protomatter issue. Protomatter is kind of like a deus ex machina--an invented substance within the context of the Trek Universe that can do anything, including defy the laws of current science.

I dunno...kinda looked like Khan's influence was in full effect in the final moments of the Genesis planet. It sure looked like it had gone to he11 to me...