Which animal has survived direct exposure to the vacuum of outer space, including its harsh radiation, in a European Space Agency experiment?
- The tardigrade (water bear)
- The desert locust
- The Antarctic krill
- The fire ant
Why A? And why not the others?
Correct answer: A. The tardigrade (water bear)
Tardigrades survive extreme stress by entering a shriveled, near-dry 'tun' state, expelling most of their body water and producing protective sugars and proteins that keep their cells intact. In 2007, the European Space Agency's FOTON-M3 mission (the TARDIS experiment) exposed tardigrades to the open vacuum of space and its cosmic and solar radiation for about ten days; a majority survived rehydration back on Earth, and some even went on to lay viable eggs. Desert locusts are famous for crossing vast, harsh deserts in swarms, but that endurance is built for heat and dehydration on Earth's surface, not the total vacuum and radiation of space. Antarctic krill tolerate the near-freezing Southern Ocean, an entirely different kind of extreme from a pressureless, airless environment. Fire ants are known for linking their bodies into living rafts to survive floods, an impressive but unrelated survival trick that has nothing to do with withstanding space conditions.
Source: European Space Agency: 'Tardigrades in space' (FOTON-M3/TARDIS, 2007); Jönsson et al., Current Biology 18(17), 2008.