Japan: Atmosphere Detected on Icy Space Rock Near Pluto

Japanese astronomers have discovered evidence of an atmosphere around a small icy body, (612533) 2002 XV93, located beyond Pluto. The discovery, published in Nature Astronomy, suggests that this space rock, approximately 500 kilometers in diameter, would be only the second object after Pluto in that region to possess an atmosphere.

(612533) 2002 XV93 is located 6 billion kilometers from the Sun and takes 247 years to complete one revolution. Astronomers observed the object as it passed in front of a distant star, noting that the star's light did not immediately reappear, indicating the presence of an atmosphere.

The atmosphere is estimated to be five to ten million times thinner than Earth's and likely composed of methane, nitrogen, and carbon monoxide. Scientists previously believed that objects of this size could not sustain an atmosphere.

While José Luis Ortiz expressed reservations, arguing that more data is needed, Ko Arimatsu emphasized that the discovery challenges existing perceptions of small icy worlds. Researchers suggest future observations with the James Webb Space Telescope to confirm the discovery and investigate the origin of the atmosphere.

Arimatsu also proposed the name Amamiku, from Okinawan mythology, for the space rock.