CAPE CANAVERAL, Florida: The solar system may have a ninth planet after all.

This one is 5,000 times bigger than outcast Pluto and billions of miles farther away, say scientists who presented “good evidence” for a long-hypothesized Planet X on Wednesday.

The gas giant is thought to be almost as big as its nearest planetary neighbor Neptune, quite possibly with rings and moons. It’s so distant that it would take a mind-blowing 10,000 to 20,000 years to circle the sun.

Planet 9, as the pair of California Institute of Technology researchers calls it, hasn’t been spotted yet. They base their prediction on mathematical and computer modeling, and anticipate its discovery via telescope within five years or less.

The two reported their research Wednesday in the Astronomical Journal because they want people to help them look for it.

“We could have stayed quiet and quietly spent the next five years searching the skies ourselves and hoping to find it. But I would rather somebody find it sooner, than me find it later,” astronomer Mike Brown told The Associated Press.

“I want to see it. I want to see what it looks like. I want to understand where it is, and I think this will help.”

Brown and planetary scientist Konstantin Batygin feel certain about their prediction, which at first seemed unbelievable to even them.

“For the first time in more than 150 years, there’s good evidence that the planetary census of the solar system is incomplete,” Batygin said, referring to Neptune’s discovery as Planet 8.

Once it’s detected, Brown insists there will be no Pluto-style planetary debate. Brown ought to know; he’s the so-called Pluto killer who helped lead the charge against Pluto’s planetary status in 2006. (Once Planet 9, Pluto is now officially considered a dwarf planet.)

“THIS is what we mean when we say the word ‘planet,’ ” Brown said.

Brown and Batygin believe it’s big — 10 times more massive than Earth — and unlike Pluto, dominates its cosmic neighborhood. Pluto is a gravitational slave to Neptune, they pointed out.