Computer simulations propose that an object roughly 730 kilometers in diameter, slightly larger than the asteroid Vesta, may have collided with Pluto billions of years ago, resulting in the formation of Sputnik Planitia, the prominent heart-shaped feature on Pluto’s surface. This impact would have likely vaporized the exterior of the object, while its dense, solid core remained intact. The core subsequently settled beneath Sputnik Planitia, potentially counteracting the gravitational forces that would have caused the feature to shift away from its equatorial location over time.
This hypothesis challenges the prevailing theory that a subsurface ocean beneath Sputnik Planitia has stabilized its position. The frigid temperatures on Pluto’s surface and the potential temperature of the subsurface ocean have raised doubts about its existence. The presence of a buried rocky remnant instead of an ocean could provide a simpler explanation for the characteristics of Sputnik Planitia.
Confirming the presence of a buried rocky remnant would require further investigation, potentially through an orbiter mission that could measure Pluto’s gravitational field. Such a mission, if approved, would take decades to reach its destination and gather the necessary data.
