It's been a busy week for astrophysicist Michel Mayor.
"If we are talking about exoplanets," Mayor told Agence France-Presse when asked about off-world colonization, "things should be clear: we will not migrate there."
The problem, according to Mayor, is sheer distance.
"Even in the very optimistic case of a livable planet that is not too far, say a few dozen light years… the time to go there is considerable," he told AFP.
"We are talking about hundreds of millions of days using the means we have available today."
With climate change putting our future on Earth in jeopardy, Mayor told AFP he wanted to "kill all the statements that say 'OK, we will go to a livable planet if one day life is not possible on Earth'," an idea he later called "completely crazy."
"We must take care of our planet," Mayor insisted. "It is very beautiful and still absolutely livable."