It's fun to imagine life on other planets being advanced alien civilizations and exotic creatures conversing in foreign languages but it's not possible to determine any of those things now.
Instead, by studying various biosignatures found in the light spectrum leaking out to Earth, researchers can speculate on what kind of photosynthesis might occur on such planets and what the extrasolar plants might look like.
Paint it black
It could be the plants are black, says Robert Blankenship, Ph.D., Lucille P. Markey Distinguished Professor in Arts & Sciences at Washington University in St. Louis. But it all depends on what size and light intensity of star – or sun – the planet feeds off, and the extrasolar planet’s atmospheric chemistry.