Nasa astronauts Sunita Williams and Butch Wilmore, after spending more than eight months in space, are expected to return to Earth on March 19. After returning, however, the two astronauts might find it difficult to readapt life on land due to Earth’s gravity.

NASA astronaut Butch Wilmore, who is spending extra time in space along with Sunita Williams, said that the two astronauts will even “feel the weight of a pencil” when they reach back on Earth.

Long-duration space travel drastically alters human physiology. In microgravity, bodily fluids shift toward the upper body, often causing what is known as "puffy face syndrome." However, once astronauts return to Earth, these fluids redistribute downward, leading to swelling in the legs and a sensation of heaviness.