50 Fun Facts About Haumea

Where in the Solar System does the dwarf planet Haumea orbit?

In the Kuiper belt: Haumea circles about 43 times farther from the Sun than Earth does, which keeps its surface below minus 220 degrees Celsius, far too cold for life as we know it.

Haumea is named after a goddess from the mythology of which Pacific islands?

Hawaii: the team put the name forward in 2006, but approval took two years while astronomers argued over who had really found the object.

The goddess Haumea presides over what?

Childbirth and fertility: in one story she stops a chief's daughter from being cut open to deliver, gives her a remedy instead, and so teaches people natural birth.

Haumea spins once about every four hours, which has distorted it into what?

An elongated, egg-like ellipsoid shape: astronomers first worked it out without seeing it, from the way Haumea's brightness rises and falls as it turns end-on and then side-on.

How did astronomers best measure Haumea's size and shape in 2017?

By watching it cross a star: telescopes at several observatories timed how long the starlight vanished, and each timing traced one slice across Haumea's outline.

How was Namaka, the smaller of Haumea's two satellites, discovered?

In images tracking the first moon: the team was photographing Haumea to follow Hiʻiaka, found five months earlier, when a fainter second speck turned up beside it.

What was discovered around Haumea in 2017, a first for any dwarf planet?

A ring: until 2014 only the four giant planets were known to have rings, and Haumea was the first world of its kind found with one.

In the myths, what does the goddess Haumea use her magical stick, the Mākālei, to do?

Turn herself young again: she returns as a girl to marry among her own descendants, generation after generation, which makes her the ancestress of each new line of chiefs.

In 2008 the IAU coined which term for distant dwarf planets such as Haumea?

Plutoid: the label arrived three months before Haumea's own name, and Ceres is the only dwarf planet it leaves out.

Haumea's two moons are named after which relatives of the goddess Haumea?

Her daughters: in the stories the two stand on opposite sides of a third sister, one cherished by her from infancy and the other her relentless pursuer.

What festive nicknames did the discovery team first give Haumea and its two moons?

Santa, Rudolph and Blitzen: the team first spotted the object on 28 December 2004, just after Christmas, and kept the theme when its moons turned up the following year.

The telescope that found Haumea's moons fired a laser skyward to correct for what?

The blurring of Earth's air: the laser makes an artificial guide star, letting the mirror cancel the atmosphere's shimmer and match the sharpness of a telescope in space.

Which Caltech astronomer led the team that spotted Haumea in December 2004?

Mike Brown: his survey turned up so many rivals to Pluto that the ninth planet was reclassified, a story he tells in his memoir How I Killed Pluto and Why It Had It Coming.

Being scooped on Haumea pushed the Caltech team to rush out news of which larger find in July 2005?

Eris: at first billed as a tenth planet, it forced the 2006 vote that created the dwarf-planet class Haumea later joined.

What did the Caltech team leader accuse the Spanish team of doing before their announcement?

Accessing his observation logs online: the rival leader later admitted looking at the logs but denied any wrongdoing, saying he was only checking whether the object was new.

Haumea's old designation, 2003 EL61, takes its year from what?

The Spanish images: they were taken in March 2003 but only searched in July 2005, seven months after Caltech had quietly spotted the same object.

Ataecina, the rival name proposed for Haumea, belonged to an Iberian goddess linked with which realm?

The underworld: naming rules keep underworld deities for bodies in one particular orbital resonance, which Haumea is not in, so the name would not have fitted.

Which team does the IAU officially credit with discovering Haumea?

Neither team: the official record gives the Spanish observatory as the place of discovery but names no discoverer, while the name itself was the one Caltech proposed.

Haumea's surface is covered mostly in what?

Crystalline water ice: the find is odd, because at Haumea's temperature ice should settle into a disordered form, which hints that something keeps resurfacing it.

Haumea's surface is about as reflective as what?

Snow: a bright speck can be a big dull world or a small shiny one, so Haumea's size stayed uncertain for years, and the best measurement found it larger and less shiny than first thought.

What large feature was detected on Haumea's surface in 2009?

A dark red spot: no telescope can see it as a shape, and it shows only as a slight change of colour in Haumea's light each time that side turns into view.

Haumea was the first of today's official dwarf planets to be found since which one?

Pluto: nothing else in the class had turned up since 1930, and then the Caltech survey found three within about three months, starting with Haumea.

Haumea's faint heat glow, which helped to fix its size, was measured by which space telescope?

Spitzer: working in the infrared, it caught the warmth of a surface colder than minus 220 degrees Celsius, which showed how much sunlight Haumea absorbs instead of reflecting.

About how long does Haumea take to travel once around the Sun?

About 300 years: NASA makes it 285, because Haumea circles some 43 times farther from the Sun than Earth does.

Haumea's orbit is unstable over the very long run; what could it become in a billion years or so?

A giant comet: if its unstable orbit ever sends it sunward, its co-discoverer reckons it could shine 10,000 times brighter than Hale-Bopp, about as bright as the full Moon.

Haumea's fast spin, odd shape and moons are all thought to result from what?

A giant collision: the glancing blow is thought to have knocked off most of Haumea's icy outer layer, and a handful of those chunks still travel on orbits like its own.

How did the Caltech team's leader first respond when the rival team announced Haumea in 2005?

He congratulated them, and even apologised for overshadowing their news with an announcement of his own the same day; his suspicions came only weeks later.

Which spacecraft observed Haumea from afar in 2007, 2017 and 2020?

New Horizons: looking back from far out in the Solar System, the probe saw Haumea lit from angles no telescope near Earth can reach, which showed how its surface scatters sunlight.

What is the smallest instrument that can show Haumea from Earth?

A big amateur telescope: at about magnitude 17, Haumea is one of the brightest bodies of its kind, yet it is still thousands of times too faint for the unaided eye.

About how long does Haumea's outer moon take to circle it once?

About 7 weeks: the moon circles so far out that one lap takes 49 days, where Pluto's big moon Charon whips round in about six.

How was Haumea's mass calculated?

From the orbits of its moons using Kepler's third law: the tighter and faster a moon circles, the heavier its parent must be, and Haumea came out at about a third of Pluto's mass.

Why did Haumea and its companions get Pacific-island names?

To honour where the moons were found: naming rules called for a deity's name, so the team looked to the myths of the islands whose mountaintop observatory first showed both moons.

In some island traditions Haumea is identified with Papa, wife of the sky father Wākea; what is Papa goddess of?

The earth: Papa and the sky father are counted the ancestors of the islands' chiefs and people, so the identification makes Haumea a mother of humankind as well as of gods.

In island myth, how were most of the goddess Haumea's children born?

From different parts of her body: several are said to have sprung from her head, and one creation chant traces a whole line of descendants to her brain.

Which goddess is a daughter of Haumea in the myths?

Pele: the stories have her arriving by canoe from a distant homeland and lighting her fires on one island after another before she found a lasting home.

Hiʻiaka, the goddess after whom Haumea's larger moon is named, is the patron goddess of what?

Hula: in one story she arrived as an egg, carried and kept warm by an elder sister, which is why her full name means 'Hiʻiaka in the bosom of' that sister.

Namaka, Haumea's smaller moon, is named after a spirit of what?

Water: in the stories Nāmaka, a goddess of the sea, hunts her fiery younger sister from island to island and cools the lava that flows into the waves.

What keeps tugging Haumea's small inner moon onto a tilted, stretched orbit?

The larger moon, Hiʻiaka: the pull is strong enough that no simple ellipse fits the little moon's path for more than a few weeks.

Which frozen gas, abundant on other big icy dwarf planets, is missing from Haumea's spectrum?

Methane: astronomers think Haumea once had such volatile ices and lost them early in its history, when its outer layers were stripped away.

What sets Haumea's orbit apart from the planets' paths?

Steeply tilted: its path leans about 28 degrees from the planets' plane, and because sky surveys long kept close to that plane, so bright a world went unfound until 2004.

What does the figure in Haumea's formal name, (136108) Haumea, record?

Its catalogue entry number: Haumea entered the official list of minor planets in September 2006, the very month Pluto was added to it as number 134340.

Beneath its icy crust, Haumea is thought to be made mostly of what?

Rock: its co-discoverer likens Haumea to an M&M, a thin shell of ice around a rocky centre, where most worlds of its kind are nearer half ice.

When it was found, Haumea ranked as the third-brightest body of its kind, after Pluto and which other?

Makemake: the most massive dwarf planet of all looks fainter than either of them, because it lies about twice as far from the Sun.

From about 2008 to 2011, what could telescopes on Earth watch the moon Namaka do?

Cross the face of Haumea: for a few years the moon's orbit lay edge-on to Earth, and one such crossing was caught from an observatory in Brazil in June 2009.

Images from which observatory revealed Haumea to the Caltech team in December 2004?

Palomar: the pictures had been taken in May, and the faint moving dot sat unnoticed in them for more than seven months until the team's search caught it three days after Christmas.

Since they formed, what are Haumea's two moons thought to have slowly done?

Drifted outward: tides raised on Haumea have pushed them away for billions of years, which is how moons born close in now circle tens of thousands of kilometres out.

About how long does sunlight take to reach Haumea?

About 6 hours: light reaches Earth in about eight minutes, and Haumea orbits some 43 times farther out, so its sunlight is always a quarter of a day old.

Haumea's orbit is loosely locked in step with the orbit of which planet?

Neptune: Haumea circles the Sun about seven times for every twelve laps Neptune makes, and the planet's repeated nudges are slowly reshaping its path.

Haumea has its own planetary symbol in Unicode; who mostly uses it today?

Astrologers: astronomers have largely dropped planetary symbols, though NASA has used this one, which a software engineer drew from two ancient carved signs.

Both of Haumea's moons were discovered in 2005 using which observatory?

W. M. Keck: its new laser-guided optics had just come into use, and the first moon showed up beside Haumea as soon as the system was pointed at it.