A tiny frozen world, smaller than Plutocould have been formed by volcanic eruptions or by the impact of a cometaccording to a study published on Monday, May 4, 2026 in the journal Nature Astronomy.
“If the atmosphere fades over the next few years, that would indicate an impact origin. If it persists or varies seasonally, that would point more to a continuous internal supply of gas,” coming from ice volcanoes, explained Ko Arimatsu, senior researcher at the National Astronomical Observatory of Japan.
According to the expert, The new planet, about 500 kilometers in diameter, would be the smallest object in the world. Solar system with an atmosphere clearly detected and retained by gravity.
The new planet has been called a “minor planet”, although formally its name is (612533) 2002 XV93. It is considered a “plutino,” orbiting the Sun twice in the time it takes Neptune to complete three orbits.
The expert added that this discovery offers a perspective on the most distant and coldest objects in the Solar System, in a region known as the Kuiper belt. At the time of the study, The minor planet was more than 5,500 kilometers away, farther even than Pluto.
“It changes our view of the small worlds of the Solar System, not just beyond Neptune,” Arimatsu wrote in an email cited by international media.
According to the study, The atmosphere of this cosmic ice ball is between 5 million and 10 million times thinner than the Earth’s atmosphere.
Arimatsu indicated that the most likely atmospheric chemicals are methane, nitrogen, or carbon monoxide; However, more observations are needed with the Webb Space Telescope, so NASAto verify its composition.
“This is an amazing advance, but it urgently needs independent verification. The implications are profound if confirmed” stated Alan Stern of the Southwest Research Institute, principal scientist for NASA’s New Horizons mission to Pluto and beyond, who was not involved in the study.