Pluto fans — and scientists — are taking umbrage with those who call another possible ‘further’ planet, ‘Planet Nine.’ Pluto was formerly known as the ninth planet in our solar system according to the International Astronomical Union (IAU) and some say that is still a controversial decision.

In case you are not up to speed, according to Space.com, ‘Planet Nine‘ is a theoretical planet that has not yet been proven to exist.

“In 2014, astronomers Scott Sheppard and Chadwick Trujillo suggested that a giant unseen “perturber” may lurk in the far outer solar system,” according to the web site. The duo said the existence of that large world would explain the peculiar orbits of some outlying objects on the solar system.

But let’s not get distracted… back to the name, ‘Planet Nine.’