Alien Life in the Pali Suttas

What do the Pali suttas say about life on other planets and the possibility of buddhas from other worlds?

I don’t know if the Pali suttas explicitly describe life on other worlds. I reconcile this by thinking about the Simsapa sutta (Handful of Leaves, SN 56.031):

“Just as the leaves in the trees are more numerous, the things that I know from direct knowledge are far more numerous than what I teach as my Dhamma. The reason I do not teach these other things is that they are not a part of my Dhamma, they are not related to my Dhamma, and they do not support the principles of a life integrated with the Eightfold Path."

That being said, it is interesting to conjecture just a wee bit. Homo Sapiens has been around for 300,000-500,000 years (some would say the current “cognitive” homo sapien has been around for as little as 70,000 years). If there have been Buddhas in other eons, or world cycles, it is clear that they were not “homo sapiens”. Thus, they must have been “alien” in the sense that perhaps they were other forms of life, such as silica-based life (instead of carbon-based life) or whatever atoms existed in that particular world cycle (i.e., based on the Planck constant for that world cycle, etc.). Most likely, these beings would have different sense organs–perhaps 10 sense organs instead of 6, and different units of social organization. In this context, it makes sense that while the essence of the dhamma is the same (dhukkha, anicca, anatta), the phrasing and description of it (10 sense doors, etc.) may be different, thus the need for a Buddha unique to that world system or planet to set the wheel of the dhamma in motion.

To continue this line of reasoning, perhaps the next Buddha will arise when physical sentient beings have a different physical manifestation than homo sapiens and thus the dhamma explained by the current Buddha is “lost” since it is no longer relatable to them (i.e., because they have different sense doors, social hierarchies, etc.). One could further conjecture that perhaps this may be closer than we think because of the potential rise of human-machine integration (i.e., Neuralink, von Neumann’s singularity, etc.–see Homo Deus by Harari).

All of this, in my thinking, makes the present moment especially precious–we live in a time when we have a unique opportunity to access the teachings and should make the most of it.