Haumea Dwarf Planet: A Rare Outlaw Planet

Haumea dwarf planet lies beyond Neptune in the Kuiper Belt, a Solar System “leftover” region of small icy bodies. Other neighboring dwarfs include Pluto, Ceres, Eris, and Makemake. Haumea has a super-fast, shape-distorting rotation, making a day last only about four hours. 

Another interesting fact about the dwarf planet is that a year on Haumea equals 285 Earth years. Keep reading to learn more about this fascinating icy planet.

Why Is Haumea Considered a Dwarf Planet?

The International Astronomical Union (IAU) sets planetary science definitions. In 2006, the IAU updated the planet’s definition. It defines celestial bodies as dwarf planets when they meet these conditions:

  • It orbits a star but is not a moon or natural satellite. 
  • It has enough mass for a nearly round shape.
  • It has not cleared the area around its orbit.

Haumea meets all of these conditions, thus making it a dwarf planet. The difference between a dwarf planet and a planet is the clearing of the neighborhood around its orbit. That means, other than its moons, the planet doesn’t share an orbit with other objects of similar size.

Currently, there are only five recognized dwarfs in the Solar System, but the number will grow as the hundreds of candidates in the Kuiper Belt get classified.

  1. Pluto
  2. Haumea
  3. Ceres
  4. Eris
  5. Makemake
dwarf planets
Image Credit: NASA

Why Does Haumea Dwarf Planet Spin So Fast?

The leading theory of the origin of dwarf planet Haumea’s tornado-speed spin states that a significant impact billions of years ago sent the dwarf into a tailspin that it has yet to recover from. 

If Haumea spins faster, the dwarf plenty will press into a dumbbell shape before eventually splitting in two. A slower spin would create a spherical object.

Why Is Haumea Oval?

Haumea’s fast spin distorts its shape, making it oval like a football. The spin pushes the dwarf planet’s equator outward. Think of it like spinning a rubber band around your finger. The faster you twirl, the more the rubber band stretches outwards. Its shape elongates but still bulges around your finger.

Haumea’s super-spin does the same, causing the dwarf planet’s fat football shape. If it rotated slower with a more spherical shape, Humea would have a larger mass like Pluto.

Haumea Dwarf Planet
Image Credit: NASA

4 Interesting Facts About Haumea

If its super-spin and rings aren’t enough to distinguish dwarf planet Haumea from its neighbors, here are some more interesting facts.


A bit of rivalry and drama surround the official discovery of the dwarf planet Haumea. Researchers, including Mike Brown of Caltech, claim credit for finding Haumea in 2004. They even published a report abstract with plans to announce the findings in September 2005.

At about the same time, another team at Spain’s Sierra Nevada Observatory found the dwarf planet when studying 2003 telescope images. In July 2005, team leader Jose Luis Ortiz emailed the Minor Planet Center (MPC) with news of the discovery. 

Official protocol states that whoever first submits a discovery report with the MPC gets the credit. The wrinkle in Haumea dwarf planet’s discovery came when Brown suspected Ortiz of reviewing his team’s observation logs. It turns out Ortiz admitted checking them but denied wrongdoing.

Instead, Ortiz and his team claimed they found the documents when searching for proof that no one else had already made the dwarf planet discovery. 


Originally designated as 2003 EL61, Haumea gained its name from the Hawaiian goddess of fertility and childbirth. 

Typically, the discovery team suggests a name for new finds. In this case, with a nod to both teams, the IAU honored the Caltech group’s name proposal of Haumea, even though they ultimately listed the Spanish team’s location, the Sierra Nevada Observatory, as the place of discovery. 


Haumea is a dwarf planet because it doesn’t have the mass to clear its neighborhood. But exactly how big is Haumea

With a radius of approximately 385 miles (620 kilometers), Haumea is smaller but close in size to Pluto. Because of its fast rotation and over-inflated football shape, its longest dimension stretches about 1,218 miles (1,960 km.) That’s about how far it is from New York City to Kansas City.

Even though it’s close in size to Pluto, Haumea has only about a third of Pluto’s mass. However, when you realize that Earth is 80% more massive than Pluto, you begin to understand just how small Haumea is. Its mass is about 1/1400th the mass of Earth.

Haumea also has roughly 1/14th Earth’s equatorial radius of approximately 3,958.8 miles. That makes Haumea the size of a sesame seed if Earth were a nickel. 

Day Length

Haumea’s days are some of the Solar System’s shortest. Its fast spin means the planet completely rotates once every 3.9 hours. 

At the other end of the spectrum, the dwarf planet has very long years. It takes about 285 Earth years to equal one Haumean lap around the Sun. In other words, if two children are born at the same time – one on each planet – when the Earth child turns one, the Haumean resident turns 285 years old. 

That’s considering that a human could even live on Humea, which you can learn about below.

Haumea Dwarf Planet’s Moons

Since Haumea dwarf planet gets its name from Hawaiian mythology, it is only fitting that its two moons, discovered in 2005, gain their names from Haumea’s mythological daughters.


Hi’iaka is the dwarf planet’s outer moon. It gets its name from the patron goddess of the island, Hawaii. Hi’iaka is also the patron goddess of hula dancers.


Namaka is Haumea’s inner moon. The name comes from Hawaiian mythology’s water spirit.

Image Credit: NASA – Haumea and her moons

Does Haumea Have Rings?

In 2017, scientists reported Haumea’s rings after they observed the dwarf planet passing in front of a star. They noted secondary events around Haumea’s main body consistent with a ring’s presence. 

The discovery noted that the ring travels in the same plane (coplanar) with the dwarf planet’s equator and Hi’iaka’s orbit. Scientists say a ring particle completes one rotation in the same period where Haumea rotates on its axis three times. 

Scientists believe Haumea’s super-spin may partially account for its moons and rings. The centrifugal force might cause space dust and debris to leave the dwarf planet’s surface to form natural satellites and rings.  

Another possibility is that a significant collision occurred billions of years ago, causing the dwarf planet to spin. Chunks breaking off during the impact created moons and rings.

Haumea is the first known Kuiper Belt Object with rings.

Illustration Credit: Stock Adobe

Could Life Exist on Haumea Dwarf Planet?

Astronomers think Haumea, like the other dwarf planets, formed about four and a half billion years ago as an ice-coated rock structure. Unfortunately, the icy worlds in the Kuiper Belt, where Haumea resides, are unsuitable for life as we know it to exist.


Haumea dwarf planet lies in a cold region beyond Neptune where leftovers from the Solar System’s beginnings reside. It is a tiny ice-covered rock about 1/1400th the mass of Earth. This odd over-inflated football-shaped dwarf planet rotates faster than any other world but takes its time orbiting the Sun.