"Thanks for the replies. That leads to my next question, what is the Thelemic stance on alien life?"

this is the question that only a very advanced alien life-form can answer - one that is able to oversee the minds of all the Thelemites of the world, and make such a conclusion on the subject that it's at the same time accurate for all of them as a whole and every one of them in particular

Jokes aside, I don't think there's any such sort of "consensus" among Thelemites regarding this subject. It's a matter of individual opinion and experience.
My personal stance is: there is alien life

The answer largely depends on your definitions of "alien" and "life".

"Thanks for the replies. That leads to my next question, what is the Thelemic stance on alien life?"

I don't know that there is one - certainly nothing official or generalizable to Thelema per se - unless it's implicit in things like the above.

Somewhere - maybe in Liber Aleph? - Crowley specifically endorses the view of planetary transmigration. The Mass goes further, and lists as options after death, "...the labor and heroism of incarnation on this planet or another, or in any Star."

.an other planet might get in earth's place and function and be the "new" earth. Earth as we know it(the particles involved) might recompose itself into an other planet of different function

.for humans who were anyway to be reincarnated they might according to timing either reincarnate on the "new" earth, or on a distant one already existing

If there is a necessity there will be a way to fulfill it.