On Jan. 19, 2019, just 161 days after its launch from Cape Canaveral Air Force Station in Florida, NASA’s Parker Solar Probe completed its first orbit of the Sun, reaching the point in its orbit farthest from our star, called aphelion. The spacecraft has now begun the second of 24 planned orbits, on track for its second perihelion, or closest approach to the Sun, on April 4, 2019.

Europe is preparing to go forward to the Moon, but how will astronauts move once they get there? Despite the Apollo missions, little is known about what lunar gravity may mean for our bodies. ESA’s space medicine team is working to find out through a series of studies.

The level of gravity on the Moon is about one sixth of Earth’s so while Apollo astronauts did not float as astronauts do on the International Space Station, they tended to hop rather than walk.