Makemake

Dwarf planet · Dwarf planet (Kuiper belt) · orbits Sun

Makemake is the second-brightest object in the Kuiper belt after Pluto, a frigid world lacquered with frozen methane. Discovered around Easter 2005 and nicknamed “Easterbunny” by its finders, it was formally named for the creator god of the Rapa Nui people of Easter Island.

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Quick facts

Its methane-ice surface reflects ~80% of the sunlight that reaches it.
Its one known moon, nicknamed MK 2, is charcoal-dark and was only spotted by Hubble in 2016.
JWST found an isotopic signature in its methane hinting at a warm, geochemically active interior.

Reading a surface no telescope can resolve

Even Hubble sees Makemake as little more than a dot, yet we know its surface is coated in methane ice. Split its faint light into a spectrum and each ice leaves unmistakable fingerprints - absorption bands at precise infrared wavelengths. Spectroscopy turns a single pixel into a chemistry report from nearly 7 billion kilometres away.

Physical characteristics

Diameter	1,430 km
Rotation period	22.8 h
Mean temperature	-240 °C
Geometric albedo	0.81
Known moons	1

Atmosphere and composition

Atmosphere	Essentially none - a 2011 stellar occultation showed no global atmosphere, though methane may sublimate locally near perihelion.
Composition	Bright ices of methane and ethane over a rocky interior, with the reddish tint of radiation-processed organics.

Discovery

Discovered by	Mike Brown, Chad Trujillo & David Rabinowitz
Year	2005
How	Palomar Observatory 48-inch Samuel Oschin Telescope

Missions

James Webb Space Telescope NASA/ESA/CSA · Space telescope · 2021 · active

The most powerful space telescope ever built, JWST observes the infrared universe with a 6.5 m gold-coated mirror from a point 1.5 million km beyond Earth. Alongside the distant cosmos it studies Solar System targets, from Jupiter’s auroras to the surfaces of Kuiper belt worlds.

What is still uncertain

Mass and density are poorly constrained - the orbit of its small moon has not yet been pinned down.