Aliens might have been carried to Earth on space dust, according to new research.
Bugs might have flown across the universe and onto our own planet, scientists have said. And bugs from our own planet might have made the same journey, flying off of Earth and onto other planets elsewhere in the galaxy.
The theory could even help explain how life began here, suggesting that it was carried from elsewhere in space then flourished in Earth.
That's according to British scientists who have studied powerful flows of interplanetary dust that can travel through space at up to 70 km (43.75 mph) per second.
They calculated that small bio-particles floating high in the atmosphere at an altitude of 93 miles (150 km) or more could be knocked free of the Earth's gravity by incoming space dust.
Eventually the tiny organisms could reach other planets in the solar system.