What's happened
Astronomers have identified a tenuous atmosphere around a small trans-Neptunian object, (612533) 2002 XV93, suggesting such tiny icy worlds can host atmospheres. The finding, published in Nature Astronomy, notes the atmosphere is far thinner than Earth’s and possibly sustained by cryovolcanism or recent impacts.
What's behind the headline?
What this means for small worlds
- This finding challenges the rule that atmospheres require larger bodies, showing 5-10 million times thinner atmospheres can exist on small icy objects.
- If cryovolcanism is ongoing, gas sources could be venting from internal ices even in extreme cold, suggesting geologic activity beyond Pluto-sized bodies.
- If the atmosphere is impact-generated, it should fade over years; persistence would imply sustained internal supply.
Why it matters to us
- Understanding atmospheres on distant bodies informs models of solar system formation and evolution.
- Webb Space Telescope observations could verify atmospheric composition and dynamics, guiding future missions.
Next steps
- Continued ground- and space-based monitoring to determine composition and variability over time.
How we got here
The object, (612533) 2002 XV93, is a plutino in the Kuiper Belt, about 5.5 billion km from the Sun. Previous assumptions held that atmospheres form only on larger bodies, but a 2024 stellar occultation observed dimming of a background star, revealing the temporary or enduring gas envelope.
Our analysis
New York Times – Kenneth Chang reports on the discovery of 2002 XV93’s atmosphere and the questions it raises about small bodies in the Kuiper Belt. AP News provides corroboration on the atmospheric measurements and the call for independent verification. The Times of Israel and AP News include discussion on possible compositions and mechanisms for the atmosphere. NY Post and CBC coverage offer alternative explanations about atmosphere-related phenomena in other contexts.
Go deeper
- What makes 2002 XV93 different from Pluto in having an atmosphere?
- How soon could Webb Space Telescope confirm the composition of the atmosphere?
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National Astronomical Observatory of Japan - Astronomical observatory
The National Astronomical Observatory of Japan is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii and Chile.