Alien Organisms Could Contaminate Earth

The growing demand for space exploration is increasing the chances of alien organisms invading Earth and of Earth-based organisms invading other planets, scientists have argued in a new paper.

The researchers point to humanity’s record of moving species to new environments on Earth, where those organisms can become invasive and harm the native species; they say such behavior suggests the same could happen with alien life from another planet contaminating Earth and vice versa, according to the paper, published Nov. 17 in the journal BioScience.

“The search of life beyond our world is an exciting endeavour that could yield an enormous discovery in the not-too-distant future,” lead author Anthony Ricciardi, a professor of invasion biology at McGill University in Montreal, told Live Science in an email. “However, in the face of increasing space missions (including those intended to return samples to Earth), it is crucial to reduce the risks of biological contamination in both directions.”