FUSE Spring 2016 - Page 6

iSCIENCE Gravity and Microgravity Ea Gravity Gravity is the name Sir Isaac Newton gave to the invisible force that keeps us 'glued' to planet Earth. It makes things fall towards the heart of the Earth and not float upwards. Gravity tugs on everything with a 'mass', working a bit like a magnet. All of the stars in the Universe, the planets and their moons have gravity. r th ’s gra v it y pull s ever y thing tow c e it s ards nt r co al re . MICROGravity You would see some signs of total weightlessness in an environment with microgravity (written “micro-g” or “µg”). But study closely and the g-forces are not actually zero, just microscopically small, which means microgravity. Plants In Space! Experiments to test the effects of microgravity can be carried out on the International Space Station, ISS. In 2004, Dutch astronaut André Kuipers grew seedlings on board as part of the Seeds in Space project investigating the effects of light and gravity. Ro logo, Co nce RHS cket S cie pyright E SA 12 years later we have project “Rocket Science”. Huge bags of rocket (lettuce) seeds were sent to the ISS ahead of Tim Peake’s December 2015 arrival. The seeds will spend several months in microgravity, then once back down on Earth, thousands of UK schoolchildren will get involved. They will plant, grow and carefully compare any seedlings to a ‘control group’ of the same seed type (‘cultivar’) that stayed on Earth. (The doomed Falcon 9 rocket was carrying the first batch of these seeds in June 2015...but don’t worry as replacements went up on the Soyuz in September 2015.) 6 FUSE