Planet found beyond Pluto has something that shouldn't exist. Here's what it is

Scientists say future observations will determine which explanation holds up. Unitl then, the mystery continues.

In Short

• Tiny icy rock 2002 XV93 beyond Pluto may have an atmosphere
• Atmosphere expected to last under 1,000 years without replenishment
• Discovery hints small distant worlds may be more active than thought

Far beyond Pluto, on the frozen outer edge of our solar system, a tiny icy rock may be holding onto a thin layer of atmosphere, surprising astronomers and scientists.

If confirmed, the discovery could change how we think about small worlds and where life's building blocks might hide.

The icy rock in question is known as 2002 XV93, a distant body roughly 500 kilometres across. To provide a better understanding of its scale, Pluto itself is nearly five times wider than 2002 XV93.

Yet this little world may have pulled off something even Pluto's neighbours aren't supposed to manage.

Most trans-Neptunian objects are so cold, and their surface gravity so weak, that they are not expected to retain atmospheres. And yet, this tiny rock hovering in space beyond the farthest body of our solar system, might prove that theory wrong.

HOW DID SCIENTISTS NOTICE IT?

The clue about the potential presence of an atmosphere came from a stroke of cosmic luck.

The orbit of 2002 XV93 is such that, as seen from Japan, it passed directly in front of a star on January 10, 2024. When a space object crosses a star, scientists watch closely. They do so because if the starlight simply snaps off, there's nothing but solid rock. But if it dims gradually, something gaseous is filtering the light.

A team of professional and amateur astronomers, led by Ko Arimatsu at NAOJ Ishigakijima Astronomical Observatory, observed the star as 2002 XV93 passed in front of it from m6ultiple sites in Japan.

The obtained data are consistent with the dimming of the atmosphere. In other words, the light faded, but it didn't vanish.

That difference is now at the heart of a much bigger question.

WHERE DID THE ATMOSPHERE COME FROM?

If the atmosphere is real, it shouldn't exist for long.

Calculations show that the atmosphere found around 2002 XV93 is expected to last less than 1,000 years unless it is replenished. So it must have been created or replenished recently.

That points to something unexpected happening recently.

Perhaps a volcanic-like eruption pushing frozen gases up from inside the object, or a comet slamming into it and releasing a burst of gas.

Either scenario would suggest these small, overlooked worlds are far more active than anyone assumed, and possibly capable of hosting the kinds of chemistry that matter for understanding how planets, and perhaps life, evolve.

Scientists say future observations will determine which explanation holds up. Until then, 2002 XV93 remains a small world with a surprisingly large story to tell.

- Ends