Makemake, likewise called 2005 FY9 and (136472 ), was found in 2005 by a group of astronomers from the California Institute of Technology led by Mike Brown.

This dwarf world lies in an area beyond Neptune that is occupied with little Solar System bodies.

It has a radius of roughly 715 km (444 miles)– simply a little smaller sized and dimmer than Pluto.

It takes about 305 Earth years for this dwarf world to make one journey around the Sun.

Formerly observed outstanding occultations recommended that Makemake did not have a significant international environment, though a thin one might not be eliminated.

Infrared information of the dwarf world hinted at perplexing thermal abnormalities and uncommon attributes of its methane ice, which raised the possibility of localized hot areas throughout its surface area and possible outgassing.

“Makemake is among the biggest and brightest icy worlds beyond Neptune, and its surface area is controlled by frozen methane,” stated Dr. Silvia Protopapa, an astronomer at the Southwest Research Institute.

“Webb exposed that methane is likewise present in the gas stage above the surface area, a finding that makes Makemake a lot more interesting.”

“It reveals that Makemake is not a non-active residue of the external Solar System, however a vibrant body where methane ice is still progressing.”

The observed methane spectral emission is analyzed as solar-excited fluorescence, which is the re-emission of sunshine taken in by methane particles.

According to the group, this might suggest either a rare environment in stability with surface area ices– comparable to Pluto– or more short-term activity, such as cometary-like sublimation or cryovolcanic plumes.

Both circumstances are physically possible and constant with the present information, provided the level of sound and restricted spectral resolution of the measurements.

“While the temptation to connect Makemake’s numerous spectral and thermal abnormalities is strong, developing the system driving the unpredictable activity stays a required action towards analyzing these observations within a merged structure,” stated Dr. Ian Wong, an astronomer at the Space Telescope Science Institute.

“Future Webb observations at greater spectral resolution will assist figure out whether the methane occurs from a thin bound environment or from plume-like outgassing.”

“This discovery raises the possibility that Makemake has a really rare environment sustained by methane sublimation,” stated Dr. Emmanuel Lellouch, an astronomer at the Paris Observatory.

“Our finest designs indicate a gas temperature level around 40 K (minus 233 degrees Celsius) and a surface area pressure of just about 10 picobars– that is, 100 billion times listed below Earth’s air pressure, and a million times more rare than Pluto’s.”

“If this situation is validated, Makemake would sign up with the little handful of external planetary system bodies where surface-atmosphere exchanges are still active today.”

“Another possibility is that the methane is being launched in plume-like outbursts,” Dr. Protopapa stated.

“In this situation, our designs recommend that methane might be launched at a rate of a couple of hundred kgs per 2nd, equivalent to the energetic water plumes on Saturn’s moon Enceladus and far higher than the faint vapor seen at Ceres.”

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Silvia Protopapa et al2025. JWST Detection of Hydrocarbon Ices and Methane Gas on Makemake. ApJLin press; arXiv: 2509.06772