Seattle's Big Blog

Covering Seattle news, weather, arts and conversation.

Is a massive planet lurking just past Pluto?


NASA released this imagining in 2006, showing what another post-Pluto planet nicknamed Xena might look like. From this distance, the sun would look like a bright star. (NASA)

The idea that there’s a giant planet orbiting the sun just past Pluto isn’t anything new; astronomers have been searching for a phantom planet for centuries. But now a researcher from the National Observatory of Brazil says he has new evidence that there’s a so-called Planet X lurking at the edges of our solar system.

Astronomer Rodney Gomes says he’s found evidence of the hulking world in the orbits of of small bodies such as the dwarf planet Sedna, which travels an oddly elongated path past Pluto. His theory is that a planet three times the size of Earth is distorting the orbits of those bodies from the far reaches of the solar system.

The planet would be too far away to impact the orbits of most objects in the solar system, but it would have  considerable pull with objects on the icy edges of the system. points out there are several plausible explanations, including:

Several planet types could fit the disturbances seen in Gomes’ calculations. For example, a Neptune-size planet, about four times bigger than Earth, orbiting 140 billion miles (225 billion kilometers) away from the sun would influence the anomalous objects in the observed manner. Or, a Mars-size planet with a highly elongated orbit — but one that always kept it well beyond the orbit of Pluto — could yield similar results. As for how it got there, the planet could have been born in and expelled from a distant star system and later captured by our sun’s gravity, Gomes said, or it could have formed near our sun and gradually been thrust outward through gravitational interactions with the other planets.

Read the full report at


Categories: Science, Space

Comments are closed.