If confirmed, the rock would become just the second world past Neptune in our solar system to host an atmosphere.

Two decades ago, the International Astronomical Union—which defines and names celestial bodies—redefined the criteria for being a planet, putting Pluto into the new category of dwarf planet

The researchers estimated that an extremely thin atmosphere, with a surface pressure between about 100 and 200 nanobars, surrounds the object. That level is far thinner than Pluto's atmosphere but stronger than anything previously measured around similar small bodies in the outer solar system.

NASA administrator Jared Isaacman declared that Pluto should be restored to its original classification as a planet.

Japanese astronomers on Monday said a tiny, little-known world beyond Pluto may possess an atmosphere, defying what had been thought possible for

NASA Administrator Jared Isaacman has reiterated his support for Pluto to be reclassified as a planet. Pluto was downgraded to a dwarf planet in 2006 because it has not cleared its orbital path of other objects. The International Astronomical Union (IAU ...

An image of Pluto taken by NASA's New Horizons spacecraft on July 13, 2015. The planet was first discovered by Clyde Tombaugh, who graduated from high school in rural Kansas and went on to earn his bachelor's and master's degrees at the University of Kansas.

Astronomers in Japan have found evidence suggesting a possible thin atmosphere around a distant icy object beyond Pluto, something previously thought unlikely for such bodies.