Neil DeGrasse Tyson said that Musk's dreams may have to contend with reality.

Tyson took to CNN to set the record straight about the logistics of life on Mars after Musk said that "humanity will reach Mars in your lifetime".

The astronomer said that the Museum of Natural History is on Mars. There are many generations of rover.

It's that robotic presence that gave Earthlings the knowledge of Mars' harsh, arid, and frigid climate, as Tyson has pointed out in the past.

He said thatAntarctica is balmier and wetter than any place on Mars.

Earth to Elon

Tyson said he's "all in" if the CEO of the two companies is serious about a Mars terraforming project.

He believes that humans are still victims of our own nature, considering the way natural disasters such as hurricanes, tornadoes, and earthquakes wreak havoc.

Tyson said that terraforming is to control the forces of your planet so that they do what you want them to do.

He thinks it's not close to time to colonize Mars.

He may be an alleged abuser and an insufferable know-it-all, but in certain cases, you really have to give it to him.

Neil deGrasse Tyson was upset by the idea of colonizing Mars.

A scientist says that Mars rock samples probably won't cause a plague.