When the Sun dies, so will the Earth. But, what we think we know about the fate of other planets in our solar system may be completely wrong.

The theorized existence of a mysterious Planet Nine — no, not Pluto — could spell disaster for some of the outer planets that aren’t currently expected to be greatly impacted when the sun dies. Researchers at the University of Warwick in the United Kingdom say a ninth planet could hurl at least one of the outer planets into interstellar space when the Sun dies.

Of course, this all won’t happen until seven billion years from now when the Sun is projected to start on the path toward becoming a white dwarf. At that time, the star at the center of our solar system will blow away half of its mass and inflate, then eventually fade into the smaller version of itself. Earth and the closer planets will be sucked into the mass at that time but the general theory is that Jupiter, Saturn, Uranus and Neptune will be pushed out to a safe distance by the blast.

But the ninth planet may change that calculus.

The planet may not be pushed out in the same way as the other eight, researchers say, and may instead head inward toward the implosion. Depending on the mass of the planet and its orbital properties, that could lead some of the large planets we think are safe into a collision course with the sun — or throw them out of its gravitational grasps altogether.

“The existence of a distant massive planet could fundamentally change the fate of the solar system,” Dr. Dimitri Veras, who led the research at UW, said. Uranus and Neptune in particular may no longer be safe from the death throes of the Sun. The fate of the solar system would depend on the mass and orbital properties of Planet Nine, if it exists.”