Haumea Facts – Explore This Fascinating Dwarf Planet

Haumea, a fascinating dwarf planet, is located in the outer reaches of our solar system within the Kuiper belt. This unique celestial object attracts attention due to its fast rotation, unusual shape, and the presence of water ice on its surface.

Third in size among the dwarf planets after Pluto and Eris, this trans-Neptunian object has intriguing characteristics that make it a subject of continuous study and observation by astronomers.

Discovered in 2004, Haumea’s rapid rotation causes it to have an elongated shape, quite unlike other planets that we are familiar with. A day on Haumea lasts just four Earth hours, making it one of the fastest rotating objects in our solar system.

With a radius of about 620 kilometers, Haumea also boasts two known moons, Namaka and Hi’iaka, adding to its array of fascinating features.

As one of the brightest objects in the Kuiper belt, Haumea can be observed on a clear night using a good-quality telescope.

Its surface is marked by a dark red spot, which is believed to be an area with a higher concentration of minerals and carbon-rich compounds compared to the surrounding icy regions.

While there’s much more to learn about this dwarf planet, the information gathered thus far on Haumea continues to pique the curiosity and interest of astronomers and space enthusiasts alike.

Physical Characteristics

Size and Shape

Haumea is a unique dwarf planet in our solar system and has an interesting size and shape. It is the third-largest known object in the Kuiper Belt, after Pluto and Eris. Haumea’s fast rotation, which means it completes a full rotation every 3.9 hours, results in a highly elongated, ellipsoidal shape similar to an American football.

This is in contrast to most other celestial bodies, which are more spherical in nature. Its diameter is approximately 1,430 miles, but it’s not uniform due to its distorted shape.

Surface and Core

The surface of Haumea is mainly composed of crystalline water ice, making it highly reflective. This implies that the core of Haumea is likely mostly composed of rocky materials.

The precise composition and structure of the core remain undetermined due to the limited observations we have.

Color and Temperature

The surface of Haumea has a noticeable dark red spot, which is thought to be due to minerals or organic materials. The temperature on Haumea is very low, as expected for an object so far from the sun. The exact temperature is still uncertain but it’s estimated to be around -241°C.

Minerals and Material Composition

Haumea’s surface is mainly composed of crystalline water ice and it is likely that other ices, such as methane or ammonia ice, could also be present. The presence of the dark red spot implies that there may be minerals or organic compounds on the surface, although their exact nature remains unknown.


There is currently no confirmed information about Haumea having an atmosphere, but it is assumed that, if it does exist, it would be very thin and likely composed of trace amounts of gases. More research is needed to confirm the presence or absence of an atmosphere.


Due to Haumea’s elongated shape and rapid rotation, its gravity is not uniform across the surface, resulting in a distinctive “dumbbell” shape. The actual value of Haumea’s gravity is not well known at this time.

Other Unique Characteristics

One of the most intriguing aspects of Haumea is its two known moons, Hiʻiaka and Namaka, both of which are also thought to consist primarily of water ice. The discovery of these moons has provided valuable insights into the formation and characteristics of the Haumea system.

Image and Look

No spacecraft has visited Haumea to take close-up images. However, based on observations from ground-based telescopes, we know that Haumea has a highly elongated ellipsoid shape with crystalline water ice surface and a dark red spot.

Scientists and artists use these pieces of information to create renderings and simulations of Haumea’s appearance.

Location and Orbit

Orbit around the Sun

Haumea, a dwarf planet located in the outer reaches of our solar system, orbits the Sun at an average distance of approximately 5.9 billion miles (9.5 billion kilometers). With an eccentric orbit, it takes Haumea around 285 Earth years to complete one full orbit.

Position in Kuiper Belt

Haumea is located in the Kuiper Belt, a vast, doughnut-shaped region of icy bodies that extends beyond Neptune’s orbit. Within the Kuiper Belt, Haumea shares its region with other known dwarf planets such as Pluto, Eris, and Makemake.

Relative Position to Earth and Other Planets

In comparison to Earth and other planets in the solar system, Haumea is quite distant. For example, it is about 50 times farther away from the Sun than Earth is and nearly 20 times farther than Neptune.

Although it is closer than Eris, it is still farther away from the Sun than both Pluto and Makemake.

Trans-Neptunian Object

Haumea is classified as a Trans-Neptunian Object (TNO), a term used to describe objects located in the outer solar system, beyond the orbit of Neptune. It is the third-largest known TNO, with only Pluto and Eris being larger.

Moons and Ring System


Haumea, the dwarf planet, has two known moons: Namaka and Hi’iaka. These moons were discovered in 2005 and named after the mythological daughters of Haumea in Hawaiian mythology. Hi’iaka is the patron goddess of the island of Hawaii and hula dancers, while Namaka is a water spirit in Hawaiian mythology.

Interesting facts about these moons:

  • Both moons are believed to have been formed from a collision between Haumea and another object.
  • Namaka orbits Haumea at an approximate distance of 39,000 km (24,000 miles).
  • Hi’iaka is slightly larger than Namaka, and it orbits Haumea at around 49,500 km (30,758 miles) from the dwarf planet’s surface.

Ring System

In addition to these moons, Haumea is also known for its unique ring system, making it the farthest known object in the solar system to possess a ring system. The discovery of Haumea’s ring system was published in the journal Nature.

Key information about Haumea’s ring system:

  • The ring is about 70 km (40 miles) wide and is at a radius of 2,287 km (1,421 miles) from the dwarf planet.
  • The ring is in the same plane with Haumea’s equator and the orbit of Hi’iaka.
  • Particles in the ring are in a 3:1 resonance with the dwarf planet’s rotation, meaning that ring particles make one revolution for every three times Haumea rotates.

In summary, Haumea’s two moons, Namaka and Hi’iaka, as well as its distinct ring system, make it an intriguing object in our solar system. Its unique characteristics continue to be a subject of interest for astronomers and researchers around the world.

Formation and Evolution


Haumea is a member of a group of objects that orbit in a disc-like zone beyond the orbit of Neptune called the Kuiper Belt. This distant realm is populated with thousands of miniature icy worlds which formed early in the history of our solar system, about 4.5 billion years ago.

Haumea is notable for the large amount of water ice on its surface, and for its size. Only Pluto and Eris are larger in the trans-Neptunian region.


Haumea’s unique elongated shape and rapid rotation, which completes a full rotation in just about four Earth hours, are believed to be the result of a massive collision that took place long ago. This impact caused the planet to lose a lot of its original icy mass and later accrete smaller fragments that reformed the object over time.

The recent relatively high albedo is thought to be due to crystalline water ice on its surface.

Haumean Family

As a consequence of the impact, several smaller objects were also created, which are now known as the Haumean family. These objects are characterized by their distinct compositions and similar orbits, indicating a common origin.

Researchers have discovered some of these fragments, such as the icy moons Hi’iaka and Namaka. Together, they constitute a family of related bodies resulting from the massive collision event mentioned earlier.


An intriguing aspect of Haumea and its family is the orbital resonance. The dwarf planet is in a 7:12 orbital resonance with Neptune, meaning that for every seven orbits Haumea completes around the Sun, Neptune completes 12.

This interaction exerts a gravitational influence on both objects and could play a role in their long-term evolution, as well as the evolution of other bodies in the Kuiper Belt.

Discovery and Naming

Discoverers and Their Observatories

Haumea was discovered in 2004 by a team headed by Mike Brown of Caltech at the Palomar Observatory in the United States and disputably also in 2005 by a team headed by José Luis Ortiz Moreno at the Sierra Nevada Observatory in Spain.

Interestingly, before its official discovery, Haumea was nicknamed “2003 EL61” due to its preliminary designation. Observations from the Keck Observatory on Mauna Kea played a significant role in determining its characteristics.

Naming and Mythology

On September 17, 2008, Haumea was named after the Hawaiian goddess of childbirth and fertility, who is also associated with hula, a traditional Hawaiian dance. The name honors the Hawaiian culture and mythology, as well as the importance of the observatories located in Hawaii, such as the Keck Observatory, that have contributed to its study.

Dwarf Planet Classification by IAU

The International Astronomical Union (IAU) designated Haumea as the fifth dwarf planet and the fourth plutoid in September 2008.

The classification of dwarf planets, along with the term “plutoid,” was introduced by the IAU to categorize objects beyond Neptune’s orbit that have a size large enough to be rounded by their own gravity but do not have enough mass to clear their orbital path of other debris.

Minor Planet Center

The Minor Planet Center is responsible for the official naming and designation of celestial bodies, including Haumea. Not only does the Center provide information on the latest discoveries and studies, but it also maintains a database to support the work of astronomers worldwide.

In summary, the discovery and naming of Haumea highlight the collaborative efforts of astronomers and observatories around the world. Its unique characteristics and connections to Hawaiian mythology make it an intriguing subject for further study.

Frequently Asked Questions

What is the composition of Haumea’s surface?

Haumea’s surface is primarily composed of crystalline water ice, making it highly reflective. There is also a dark red spot on the dwarf planet, which is believed to have a higher concentration of minerals and carbon-rich compounds than the rest of the icy surface.

How did Haumea get its distinct shape?

Haumea has a unique elongated shape that resembles a football. This is due to its fast rotation – it is one of the fastest rotating large objects in our solar system. The rapid spin causes its shape to become distorted.

What is Haumea’s orbital period around the Sun?

Haumea takes approximately 283.3 Earth years to complete one orbit around the Sun. The dwarf planet’s highly elongated orbit takes it far beyond Neptune and into the outer edges of the Kuiper Belt.

What is the significance of Haumea’s ring system?

Haumea is the farthest known object in the solar system to possess a ring system, which was discovered in 2017. This finding is quite unusual for objects at such a distance from the Sun. The presence of these rings provides new insights into the formation and evolution of small bodies in the outer solar system.

How were Haumea’s moons discovered?

The two moons of Haumea, known as Hi’iaka and Namaka, were discovered in 2005 by a team led by Mike Brown at the Palomar Observatory in California. The moons were found through observations with ground-based telescopes, which were also used to study the dwarf planet itself.

What is the temperature on Haumea’s surface?

Haumea’s surface temperature is estimated to be around -241 degrees Celsius (-402 degrees Fahrenheit). This extremely low temperature can be attributed to its great distance from the Sun and the presence of frozen water ice on its surface.