Could an extraterrestrial plant survive inside of a meteor as it enters a planet's atmosphere?

Question

A common theme in media is that an alien lifeform comes to Earth by clinging to a meteor that was once part of the alien's homeworld. Usually, these aliens are either bacteria, viruses, or germs, creatures that are very tough and can survive the extreme heat of a meteor entering a planet's atmosphere.

Plantlife isn't the most durable and is very susceptible to fire and heat, so it would be unlikely to survive on the exterior of a chunk of rock flying through space. If this plant instead was inside of the meteor instead of on the surface would it be able to survive being volleyed to Earth?

Answer 1

Eon-long stellar journeys and flaming atmospheric entries are harsh environments for any life form, not only plants; but plants have evolved a wonderful mechanism for surviving temporary harsh conditions. It is called, "a seed".

Wrapping its vital genetic information in a nutrient-rich medium and then wrapping that kernel in a hard shell, along with some genetic coding which allows that information to lay dormant until specific environmental stimuli are present, the plant's species is able to survive long frigid winters and blisteringly hot dry spells.

This mechanism, if implemented to an extreme, might allow your stellar wandering flora to survive the rigors of its millennia-long journey. And the fires of falling through the atmosphere might be just the right stimuli to let it know that it was finally time to sprout.

Answer 2

As the previous respondent noted a seed (or better yet a spore) might survive a multi million year journey through the cold and vacuum of space followed by the heat and impact of a descent to the Earths surface if buried deep inside a meteor large enough for the its core not to heat up too much as a result of air friction and the kinetic energy of impact. Unlikely in the extreme but possible (I suppose).

This however leaves the question of how exactly the plant got into the center of the meteor in the first place and then how the meteor, which was presumably part of the planet where the spore originated got blown into space to start with.

It might be easier to just assume instead the spore (which would be minute) was just drifting in the upper levels of its home planet's atmosphere when some catastrophic event destroyed the planet. The odds of any one spore surviving and making it into space would be astronomical but if there were billions of spores in the air at the time?

After that, sunlight gradually propels the surviving spores - which are amazingly hardy BTW off in random direction into deep space. Once it drifts into Earths orbit and gets captured its low mass, the ultra thin atmosphere it initially encounters & low velocity (relative to Earth) let it drift down to the surface.

Answer 3

The atmospheric entry would be the easy part: meteorites don't get hot on the inside:

"Rocky asteroids are poor conductors of heat [...].Their central regions remain cool even as the hot outer layers are ablated away." — Donald Yeomans, manager of NASA's Near Earth Object program at JPL.

The next part would be getting out, so we'd need to posit that the meteorite split on impact, or was helpfully busted by a curious human.

Surviving the space trip would be tough, but one can conceive of seeds or spores, maybe even cells, that might remain viable, especially if the species had evolved to tolerate high radiation levels and long dry cold.

Now, the hardest part: how did it get in there to begin with? On earth a seed (or fossil) could be trapped in sedimentary rock, but it's hard to imagine sedimentary rocks surviving a planet's breakup as anything more than a cloud of sand. Perhaps the clump of sedimentary rock was swept by a fast lava stream into an ocean, where it cooled quickly enough that the seed remained viable, and then later the whole assemblage of seed inside sedimentary inside igneous got ejected in a cataclysm and sent our way like a peanut M&M tossed at a seagull. In a hard sci-fi story I think I'd buy it. Can't guess what a planetary scientist would say.

Answer 4

You may find an answer here:

Panspermia (from Ancient Greek πᾶν (pan) 'all', and σπέρμα (sperma) 'seed') is the hypothesis that life exists throughout the Universe, distributed by space dust, meteoroids, asteroids, comets, planetoids, and also by spacecraft carrying unintended contamination by microorganisms. Distribution may have occurred spanning galaxies, and so may not be restricted to the limited scale of solar systems.[

https://en.wikipedia.org/wiki/Panspermia

Answer 5

My answer to:

https://scifi.stackexchange.com/questions/240935/novel-sentient-lifeform-enslaves-all-life-on-planet-colonises-other-planets-b/240976#240976[1]

Mentions the classic science fiction story "Seeds of the Dusk" 1938, by Raymond Z. Gallun, in which intelligent Martian plants send billions of spores into space and one lands on Earth and sprouts.

Panspermia (from Ancient Greek πᾶν (pan) 'all', and σπέρμα (sperma) 'seed') is the hypothesis that life exists throughout the Universe, distributed by space dust,1 meteoroids,2 asteroids, comets,[3] planetoids,[4] and also by spacecraft carrying unintended contamination by microorganisms.[5][6][7] Distribution may have occurred spanning galaxies, and so may not be restricted to the limited scale of solar systems.[8][9]

The first known mention of the term was in the writings of the 5th-century BC Greek philosopher Anaxagoras.[20] Panspermia began to assume a more scientific form through the proposals of Jöns Jacob Berzelius (1834),[21] Hermann E. Richter (1865),[22] Kelvin (1871),[23] Hermann von Helmholtz (1879)[24][25] and finally reaching the level of a detailed scientific hypothesis through the efforts of the Swedish chemist Svante Arrhenius (1903).[26]

Fred Hoyle (1915–2001) and Chandra Wickramasinghe (born 1939) were influential proponents of panspermia.[27][28] In 1974 they proposed the hypothesis that some dust in interstellar space was largely organic (containing carbon), which Wickramasinghe later proved to be correct.[29][30][31] Hoyle and Wickramasinghe further contended that life forms continue to enter the Earth's atmosphere, and may be responsible for epidemic outbreaks, new diseases, and the genetic novelty necessary for macroevolution.[32]

https://en.wikipedia.org/wiki/Panspermia[2]