Makemake earned the nickname “Easterbunny” because its discovery team found it just days after Easter 2005. Mike Brown, Chad Trujillo, and David Rabinowitz identified the object in images taken on March 31, 2005, only four days after Easter Sunday fell on March 27 that year. The team needed a quick internal code name while keeping the discovery under wraps, and “Easterbunny” stuck. When the International Astronomical Union (IAU) formally named the dwarf planet in 2008, the chosen name preserved the Easter connection in a subtler way, drawing on the mythology of Easter Island itself.
How Astronomical Nicknames Work Behind the Scenes
When astronomers spot a new object in the outer solar system, it receives a provisional designation based on when it was found. Makemake’s was 2005 FY9, a string that tells professionals the year and half-month of discovery but means nothing to anyone else. Discovery teams often give their finds informal nicknames while the object awaits confirmation and formal naming, a process that can take years. Mike Brown’s team was particularly fond of playful code names. Eris, the largest known dwarf planet beyond Neptune, was internally called “Xena” after the TV warrior princess. Haumea went by “Santa” because it was identified near Christmas. And the object found just after Easter got “Easterbunny.”
These nicknames are never meant for public consumption, but they inevitably leak. Brown himself discussed them openly in lectures and on his website, so by the time Makemake received its official name in July 2008, millions of space enthusiasts already knew it as Easterbunny. The nickname carried an affection that sterile catalog numbers never could, which is part of why the naming story has lingered in popular memory.
From Easterbunny to Makemake
The IAU has specific guidelines for naming objects in different regions of the solar system. Trans-Neptunian dwarf planets, the class Makemake belongs to, are supposed to receive names drawn from creation mythologies around the world. The “plutoid” designation introduced for these objects cemented the expectation that names would carry mythological weight.1Proceedings of the International Astronomical Union. DIVISION III / WORKING GROUP COMMITTEE ON SMALL BODIES NOMENCLATURE “Easterbunny” obviously wouldn’t fly under those rules, but Brown wanted to preserve the Easter thread. He found the solution on Easter Island.
Makemake (pronounced roughly “MAH-keh MAH-keh”) is the chief creator god in the mythology of the Rapa Nui, the indigenous Polynesian people of Easter Island. In their tradition, Makemake created humanity, presided over the annual birdman competition, and was associated with fertility and the egg, a symbol that resonates with the Easter season in a different cultural register. By choosing this name, Brown satisfied the IAU’s mythology requirement while embedding a quiet nod to the Easter timing of the discovery. The name was approved in July 2008, the same session in which the IAU formalized the dwarf planet classification for Makemake alongside Pluto, Eris, Haumea, and Ceres.
Who Is Makemake in Rapa Nui Mythology
The Rapa Nui religion centered on ancestor worship and a handful of powerful deities, with Makemake sitting at the top. He was the creator of humanity and the god of fertility, and he played a central role in the tangata manu, or birdman cult, which dominated Easter Island’s ritual life for several centuries. Each spring, representatives from competing clans would race to retrieve the first egg of the sooty tern from a nearby islet. The winner’s patron became the birdman, wielding significant political and spiritual authority for the following year. Makemake presided over this entire ritual cycle.
Petroglyphs of Makemake are carved throughout the island, typically depicting a round face with large, staring eyes. European missionaries who arrived in the nineteenth century recorded local oral traditions about him, though much of the mythology was lost during the devastating slave raids and epidemics that decimated the Rapa Nui population in the 1860s. What survived paints Makemake as a god with creative power over both the natural and human worlds, making him an apt namesake for a creation-mythology naming convention.
What Makemake Actually Is
Makemake is one of five recognized dwarf planets in the solar system and the third largest after Pluto and Eris. It orbits the Sun in the Kuiper Belt, a vast ring of icy bodies beyond Neptune, at an average distance of about 45 times Earth’s distance from the Sun. That puts it so far away that sunlight takes over six hours to reach it, and it takes roughly 306 Earth years to complete one orbit.
Stellar occultation measurements, where astronomers watch the object pass in front of a distant star and use the dimming to calculate size, have given us reasonably precise dimensions. One study measured projected axes of about 1,430 by 1,502 kilometers, confirming that Makemake is a little smaller than Pluto and Eris.2Nature. Albedo and atmospheric constraints of dwarf planet Makemake from a stellar occultation A separate analysis found a nearly spherical shape, with an equatorial diameter of about 1,434 kilometers and very little elongation, suggesting the body is close to round.3Astrophysical Journal Letters. On the Size, Shape, and Density of Dwarf Planet Makemake For context, that makes Makemake roughly two-thirds the diameter of our Moon.
A Bright, Frigid Surface
Makemake is one of the most reflective objects in the outer solar system. Its geometric albedo, the fraction of incoming light it bounces back, sits at roughly 0.7 to 0.8, placing it between the even brighter Eris and the somewhat darker Pluto.4The Astronomical Journal. The Rotation Period and Light-Curve Amplitude of Kuiper Belt Dwarf Planet 136472 Makemake (2005 FY9) That high reflectivity is why Makemake, despite being more distant, was the brightest undiscovered object in the Kuiper Belt for decades. It is bright enough to be seen through a good amateur telescope under dark skies, a rarity for objects that far out.
The reason for all that brightness became clearer with recent observations from the James Webb Space Telescope. JWST’s infrared instruments detected a complex mix of ices on Makemake’s surface, including methane, methanol, ethane, and acetylene.5The Astrophysical Journal Letters. JWST Detection of Hydrocarbon Ices and Methane Gas on Makemake The best-fitting model of the surface involves layers of hydrocarbon ices sitting on top of methane-rich deposits, a structure that points to slow chemical processing by ultraviolet radiation over millions of years. Fresh methane frost is highly reflective, which helps explain why Makemake shines so brightly despite sitting in the deep cold of the outer solar system where temperatures hover around minus 240 degrees Celsius.
One striking finding from the occultation work is that Makemake lacks a global atmosphere like Pluto’s. Pluto has a thin nitrogen atmosphere that was confirmed when New Horizons flew past in 2015, and astronomers wondered if Makemake, being similar in size and surface composition, might have one too. The occultation data showed no sign of it. The star blinked out sharply as Makemake’s edge crossed it, rather than fading gradually as it would if filtered through an atmosphere.2Nature. Albedo and atmospheric constraints of dwarf planet Makemake from a stellar occultation This absence is still not fully explained, since Makemake’s surface methane should, in theory, sublimate into a thin gas layer at its current distance from the Sun.
A Moon Hiding in Plain Sight
For years, Makemake appeared to be a loner. Searches for satellites came up empty, which was unusual because most large Kuiper Belt objects have at least one moon. Then, in 2016, astronomers announced that Hubble had spotted a faint companion in images taken the previous April. The moon, provisionally called S/2015 (136472) 1 and informally nicknamed MK2, was about eight magnitudes fainter than Makemake and sitting very close to it, at a separation of just 0.57 arcseconds.6The Astrophysical Journal Letters. DISCOVERY OF A MAKEMAKEAN MOON
The discovery team explained that MK2 had likely evaded earlier detection because its orbit is nearly edge-on as seen from Earth. That geometry means the moon spends a large fraction of its orbital period buried in Makemake’s glare, invisible even to Hubble unless it happens to be near its greatest elongation from the parent body. Subsequent analysis of archival Hubble images from 2015 through 2019 detected MK2 on twelve out of thirteen observation days and produced a preliminary circular orbit with a period of about 18 days, a semimajor axis of roughly 22,250 kilometers, and an inclination of about 84 degrees relative to our line of sight, confirming the near-edge-on orientation.7arXiv. A preliminary orbit for the satellite of dwarf planet (136472) Makemake
MK2 matters for more than completeness. A moon’s orbit lets astronomers calculate the mass of the system it orbits, which in turn gives the density when combined with size measurements. Early estimates suggested Makemake has a density consistent with a rocky core surrounded by an icy mantle, similar to Pluto but with a thinner ice shell. The moon is also very dark compared to Makemake’s bright surface, hinting that MK2 might be a captured object rather than debris from a giant impact, though the data remain too sparse to be sure.
Why Was It Not Found Sooner
Makemake is bright enough that you might wonder how it avoided discovery until 2005. The answer is a combination of bad luck and practical limitations. Most early surveys for outer solar system objects concentrated on the ecliptic plane, the thin band where the majority of solar system bodies orbit. Makemake’s orbit is tilted about 29 degrees to the ecliptic, which means it spends long stretches of time in parts of the sky that surveys historically neglected.
Photographic plate surveys in the twentieth century also struggled with the sheer volume of sky to cover and the slow motion of distant objects. Makemake moves so slowly against the background stars, a consequence of its vast distance, that it could easily be mistaken for a star on a single-night exposure. Only with systematic digital surveys that compared images taken days or weeks apart did the tiny shift in position become detectable. Brown’s team used the 48-inch Samuel Oschin Telescope at Palomar Observatory with a wide-field CCD camera specifically designed for this kind of slow-moving target search. Without that combination of wide coverage and repeat imaging, Makemake would have stayed hidden even longer.
Mike Brown’s Naming Philosophy
Brown has written and spoken extensively about the process of choosing names for his discoveries, and the “Easterbunny” story is part of a broader pattern. He treated the informal naming stage as a personal ritual, picking nicknames that reflected the circumstances of discovery rather than any physical property of the object. The Christmas-season discovery of Haumea got “Santa.” Eris, found in an era of heated debate over Pluto’s planetary status, was dubbed “Xena” partly for fun and partly because the name’s cultural currency guaranteed media attention.
When it came time to formalize, Brown often searched for mythological names that honored cultures connected to the nickname’s theme. Haumea is the Hawaiian goddess of childbirth and fertility, linking back to its “Santa” birth-timing nickname through the idea of a winter gift. Makemake kept the Easter thread by drawing on the mythology of Easter Island. Brown has said he saw the naming process as a chance to highlight mythologies that rarely appear in astronomical catalogs, which have historically leaned heavily on Greco-Roman traditions. The outer solar system’s naming rules, with their emphasis on creation deities from diverse cultures, gave him that opening.
Could We Ever Visit Makemake
No spacecraft has visited Makemake, and none is currently approved to go. The distance alone is daunting. At roughly 52 astronomical units from the Sun at its current position, Makemake is more than three times farther away than Saturn. A mission using conventional chemical propulsion and a Jupiter gravity assist, similar to New Horizons’ path to Pluto, would still take decades.
Conceptual studies have explored whether advanced propulsion could shorten the trip. One proposal examined a Direct Fusion Drive, a type of nuclear fusion engine still in development, and found that it could theoretically deliver a 1,500-kilogram payload to Makemake in under ten years, using a thrust-coast-thrust trajectory profile.8Acta Astronautica. Exploration of trans-Neptunian objects using the Direct Fusion Drive The same engine concept was analyzed for missions to Eris and Haumea as well, with similar timescales.9arXiv. Exploration of the solar system and beyond using a thermonuclear fusion drive These are paper studies, not engineering programs, and fusion propulsion remains far from flight-ready. But the fact that credible mission architectures exist on paper keeps Makemake on the long-term wish list for planetary scientists who want to understand the diversity of icy worlds in the outer solar system.
A flyby mission, where the spacecraft screams past at high speed and collects data during a brief window, would be technically easier than a rendezvous but scientifically limited. What researchers really want is an orbiter that can study the surface, measure the gravitational field to confirm the interior structure, and observe MK2 up close. The occultation and JWST data have given us a surprisingly detailed picture for a world we have never visited, but there is no substitute for proximity. The patchy, layered ice composition hinted at by JWST, the missing atmosphere, the dark little moon in its nearly edge-on orbit: all of these are puzzles that would take years of close observation to untangle.
Other Dwarf Planets with Unusual Nicknames
Makemake’s “Easterbunny” phase was memorable, but it was not the only outer solar system object to carry a pop-culture nickname before receiving its official designation. Eris’s “Xena” moniker was arguably more famous, generating headlines because it invoked a beloved TV character and because the object’s discovery directly triggered the demotion of Pluto. Some fans lobbied the IAU to keep “Xena” as the official name, but the rules required a name from mythology, and the team chose Eris, the Greek goddess of discord, reflecting the chaos the discovery had caused in planetary science. Eris’s moon Dysnomia, named for the Greek spirit of lawlessness, was itself a hidden joke: the actress who played Xena, Lucy Lawless, lent her surname to the etymological root.
Haumea’s backstory was more contentious. Two teams claimed credit for the discovery, and the naming process became entangled in a priority dispute that dragged on for years. The informal nickname “Santa” eventually gave way to Haumea, but the controversy over who deserved the discovery credit lingered much longer than the naming debate. Sedna, another distant icy body that is not officially a dwarf planet but is often discussed alongside them, was named for the Inuit goddess of the sea because it was found in a frigid, lonely region of the solar system. Brown has said he wanted a name that evoked cold and isolation, and the Inuit mythology fit perfectly.
The pattern across all these objects is that the informal names captured something personal and immediate about the discovery moment, while the formal names reached into global mythology to honor traditions far removed from the California observatories where the objects were found. The “Easterbunny” story endures in part because it is a neat encapsulation of that transition: a lighthearted inside joke that became a bridge to one of the most fascinating, and least well-known, mythological traditions in the Pacific.