Submission + - Astronauts' Hearts Change Shape in Space (sciencemag.org)
sciencehabit writes: Astronauts who go into space come back with rounder hearts. Scientists who had astronauts regularly take images of their hearts with ultrasound machines found that the organ becomes more spherical in space by a factor of 9.4%. The researchers believe the change in shape, which is temporary, indicates that the heart is performing less efficiently in zero gravity.