Question

Why does space alters human heart cells which return to normal on earth ?​

Answer 1

Answer:

Heart cells are altered in space but return to normal within 10 days on Earth, say researchers who examined cell-level cardiac function and gene expression in human heart cells cultured aboard the International Space Station (ISS) for 5.5 weeks.

Exposure to microgravity altered the expression of thousands of genes, but largely normal patterns of gene expression reappeared within 10 days after returning to Earth, according to the study published in the journal Stem Cell Reports.