Neil deGrasse Tyson says he was shocked at how people reacted when he helped 'cancel Pluto'

Astrophysicist Neil deGrasse Tyson says he received hate mail from children as young as eight after the news broke that Pluto would no longer be considered a planet.

The former planet was demoted to the status of dwarf planet in August 2006 by the International Astronomical Union - and Tyson has repeated comments it was right for it to be declassified at the time.

But speaking to Jeremy Corbett on The Project ahead of his tour in Aotearoa in July, Tyson revealed while he still received some hate mail for the decision, it had largely "calmed down".

"Do you still get hate mail from kids for cancelling Pluto?" Corbett asked.

"I was accessory to the demotion of Pluto," the astrophysicist said.

"I didn't pull the trigger but I definitely drove the getaway car. All of the eight-year-old and nine-year-old children when that decision was made lost their minds.

"'Well now how am I going to memorise the planets?'," he said children had repeatedly asked him.

"Wow, people are really attached to this. But the next crop of kids are now trained in a Pluto-less solar system from the beginning, so I think they outgrew it and the hate mail has calmed down."

Watch the video from The Project above.