Inspired by entrepreneur Elon Musk’s ambition to make humanity a multiplanetary species, US President Donald Trump has issued one of NASA’s biggest challenges: landing humans on Mars. This push for the red planet has been met with mixed feelings by the planetary-science community, which has raised concerns about the budget, the physical integrity of astronauts and the scientific return on investment (see Nature 2025). However, one key issue remains unaddressed: what if there is life on Mars?
Competing Interests
The author declares no competing interests.
