tardigrade genome
Tardigrades have unique abilities to survive in harsh environments — this is a scanning electron microscope image of the hydrated tardigrade Tanaka S, Sagara H, Kunieda.

Two microscopic organisms have been selected as the future candidates to be the very first Earth-dwelling creatures to travel to interstellar space. The two organisms are Caenorhabditis elegans and tardigrades. The mission that plans to enlist the two creatures is called Starlight. The Nasa-supported mission involves using a massive laser beam to shove a small spacecraft — around the size of a standard smartphone — out of the solar system.

"We are developing the capability to test whether terrestrial life as we know it can exist in interstellar space by preparing small life-forms — C. Elegans and radiation-resistant tardigrades — which are ideal candidates to be our first interstellar travelers," said Starlight lead scientist Philip Lubin at the University of California, Santa Barbara (UCSB), Space.com reported.

Caenorhabditis elegans, a tiny roundworm and a nematode species found in soil samples across the world, has been extensively used by scientists to study a variety of subjects including sleep and ageing. What is more, they've already travelled to space aboard the ISS (International Space Station), orbiting around the Earth. On the other hand, tardigrades are considered to be one of the hardiest organisms on our planet, capable of even surviving the end of Earth. Therefore, both the organisms can be considered the ideal candidates for interstellar space travel.

"Besides being microscopic, and thus conveniently fitting on our first interstellar wafer craft, they can be frozen and put into a state of anhydrobiosis, meaning they can be dehydrated and put into suspended animation," the Starlight team wrote on the project website. "When they are re-hydrated, they wake up as good as new!"

However, it is still uncertain when such a mission would be ready for launch. It would take the tiny spacecraft carrying the two organisms, travelling at incredible speeds around 20 years after launch to reach the nearest star or planet outside our solar system.

"This is a long-term humanity-changing program," Lubin said, Space.com reported. "The biggest challenge is that Nasa, the US government, does not plan 30 to 50 years ahead in space. Perhaps a public/private alliance is needed. Similarly, what may be required is a new division of Nasa or new agency whose mandate is interstellar flight.

"It will not be easy. There are many difficult technical issues. It will not be cheap. But it is possible."