Scientists are still learning how spending prolonged periods of time in the microgravity of space can affect astronauts’ health. They found that spaceflight caused the brains of the astronauts to shift both up and backward “in a fashion that correlated with exposure duration.” The brains of the bed rest study participants were found to shift backwards but not nearly as much upwards as the astronauts’ brains, indicating that spaceflight had a more pronounced effect on the brain. The researchers found that astronauts who spent longer periods in space had more difficulties regaining their balance upon their return compared to those who embarked on shorter missions. While “widespread recovery occurred in all three dimensions over six months following spaceflight,” some of these deformations persisted beyond that point for some of the astronauts. And these are just some of the unanswered questions that we need to sort out.”More on astronaut health: Something Is Malfunctioning With Astronauts’ Brains