Discovered in 2005, Makemake, a Kuiper Belt Object (KBO) has . Credit: NASA

The Dwarf Planet (and Plutoid) Makemake

19 Aug , 2015 by

In 2003, astronomer Mike Brown and his team from Caltech began a discovery process which would change the way we think of our Solar System. Initially, it was the discovery of a body with a comparable mass to Pluto (Eris) that challenged the definition of the word “planet”. But in the months and years that followed, more discoveries would be made that further underlined the need for a new system of classification.

This included the discovery of Haumea, Orcus and Salacia in 2004, and Makemake in 2005. Like many other Trans-Neptunian Objects (TNOs) and Kuiper Belt Objects (KBOs) discovered in the past decade, this planet’s status is the subject of some debate. However, the IAU was quick to designate it as the fourth dwarf planet in our Solar System, and the third “Plutoid“.

Discovery and Naming:
Makemake was discovered on March 31st, 2005, at the Palomar Observatory by a team consisting of Mike Brown, Chad Trujillo and David Rainowitz. The discovery was announced to the public on July 29th, 2005, coincident with the announcement of the discovery of Eris. Originally, Brown and his team had been intent on waiting for further confirmation, but chose to proceed after a different team in Spain announced the discovery of Haumea on July 27th.

The provisional designation of 2005 FY9 was given to Makemake when the discovery was first made public. Before that, the discovery team used the codename “Easterbunny” for the object, because it was observed shortly after Easter. In July of 2008, in accordance with IAU rules for classical Kuiper Belt Objects, 2005 FY9 was given the name of a creator deity.

    Photograph of Makemake taken by the Hubble Space Telescope. Credit: NASA/Mike Brown

Photograph of Makemake taken by the Hubble Space Telescope. Credit: NASA/Mike Brown

In order to preserve the object’s connection with Easter, the object was given a name derived from the mythos of the Rapa Nui (the native people of Easter Island) to whom Makemake is the creator God. It was officially classified as a dwarf planet and a plutoid by the International Astronomical Union (IAU) on July 19th, 2008.

Size, Mass and Orbit:
Based on infrared observations conducted by Brown and his team using the Spitzer Space Telescope, which were compared to similar observations made by the Herschel Space Telescope, an estimated diameter of 1,360 – 1,480 km was made. Subsequent observations made during the 2011 stellar occulation by Makemake produced estimated dimensions of 1502 ± 45 × 1430 ± 9 km.

Estimates of its mass place it in the vicinity of 4 x 10²¹ kg (4,000,000,000 trillion kg), which is the equivalent of 0.00067 Earths. This makes Makemake the third largest known Trans-Neptunian Object (TNOs) – smaller than Pluto and Eris, and slightly larger than Haumea.

Makemake has a slightly eccentric orbit (of 0.159), which ranges from 38.590 AU (5.76 billion km/3.58 billion mi) at perihelion to 52.840 AU ( 7.94 billion km or 4.934 billion miles) at aphelion. It has an orbital period of 309.09 Earth years, and takes about 7.77 Earth hours to complete a single sidereal rotation. This means that a single day on Makemake is less than 8 hours and a single year last as long as 112,897 days.

A selection of dwarf planets, sometimes considered trans-Neptunian objects depending on their interactions with the planet Neptune. Credit: NASA/STSci

A selection of dwarf planets, sometimes considered trans-Neptunian objects depending on their interactions with the planet Neptune. Credit: NASA/STSci

As a classical Kuiper Belt Object, Makemake’s orbit lies far enough from Neptune to remain stable over the age of the Solar System. Unlike plutinos, which can cross Neptune’s orbit, classical KBOs are free from Neptune’s perturbation. Such objects have relatively low eccentricities (below 0.2) and orbit the Sun in much the same way the planets do. Makemake, however, is a member of the “dynamically hot” class of classical KBOs, meaning that it has a high inclination compared to others in its population.

Composition and Surface:
With an estimated mean density of 1.4–3.2 g/cm³, Makemake is believed to be differentiated between an icy surface and a rocky core. Like Pluto and Eris, the surface ice is believed to be composed largely of frozen methane (CH4) and ethane (C2H6). Though evidence exists for traces of nitrogen ice as well, it is nowhere near as prevalent as with Pluto or Triton.

Javier Licandro and his colleagues at the Instituto de Astrofisica de Canarias performed examinations of Makemake using the William Herschel Telescope and Telescopio Nazionale Galileo. According to their findings, Makemake has a very bright surface (with a surface albedo of 0.81) which means it closely resembles that of Pluto.

In essence, it appears reddish in color (significantly more so than Eris), which also indicates strong concentrations of tholins in the surface ice. This is consistent with the presence of methane ice, which would have turned red due to exposure to solar radiation over time.

Atmosphere:
During it’s 2011 occultation with an 18th-magnitutde star, Makemake abruptly blocked all of its light. These results showed that Makemake lacks a substantial atmosphere, which contradicted earlier assumptions about it having an atmosphere comparable to that of Pluto. However, the presence of methane and possibly nitrogen suggests that Makemake could have a transient atmosphere similar to that of Pluto when it reaches perihelion.

Makemake. Credit: NASA

Artist’s impression of the surface of Makemake. Credit: NASA

Essentially, when Makemake is closest to the Sun, nitrogen and other ices would sublimate, forming a tenuous atmosphere composed of nitrogen gas and hydrocarbons. The existence of an atmosphere would also provide a natural explanation for the nitrogen depletion, which could have been lost over time through the process of atmospheric escape.

Exploration:
Currently, no missions have been planned to the Kuiper Belt for the purpose of conducting a survey of Makemake. However, it has been calculated that – based on a launch date of August 21st, 2024, and August 24th, 2036 – a flyby mission to Makemake could take just over 16 years, using a Jupiter gravity assist. On either occasion, Makemake would be approximately 52 AU from the Sun when the spacecraft arrives.

Makemake is now the fourth designated dwarf planet in the solar system, and the third Plutoid. In the coming years, it is likely to be joined several more objects in the Trans-Neptunian region that are similar in size, mass, and orbit. And assuming we mount a flyby to the region, we may discover many similar objects, and learn a great deal more about this one.

We have many interesting articles on Makemake and the Kuiper Belt here at Universe Today. Here’s How Many Planets are in the Solar System, and Makemake’s Mysterious Atmosphere.

Original News Sources: Mike Brown’s Planets, Slashdot

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Laurel Kornfeld
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Laurel Kornfeld
July 14, 2008 8:54 AM

This object adds one more planet–that’s right, planet–to our solar system. The plutoid category is downright ridiculous. This object is in hydrostatic equilibrium; therefore, it is a planet of the dwarf planet subcategory. Dr. David Rabinowitz, one of its co-discoverers, is also one of the signatories of Dr. Alan Stern’s petition rejecting the IAU 2006 planet definition that states that dwarf planets are not planets at all.

Dwarf planets are planets. To find out more about the movement to reinstate them under the umbrella of planets, visit http://www.geocities.com/dwarf_planets_are_planets_too/

LLDIAZ
Guest
LLDIAZ
July 14, 2008 9:36 AM

All spherical objects should be named planets or moons. Any thing else just complicates things.
Where do you draw the line?
Why is Mercury a planet and Pluto not.?
These things need to be clarified…

Dan
Guest
July 14, 2008 9:12 AM
If Clyde Tombaugh had just had a little better telescope or a little bit more luck he could have found Makemake in his heroic 1930’s outer plants hunt: Back then this Kuiperoid was even brighter than today. (I’ve tried in vain, though, to get the people at Lowell Obs. to check whether Makemake does actually show up on one of his plates.) Now if Clyde would have given the world two faint transneptunian bodies in rapid succession, I bet none of them would have been given the label “planet” in the first place: The parallels to the flood of discoveries in the asteroid main belt in the 1st half of the 19th century would have been obvious, and… Read more »
Craig Whitman
Guest
Craig Whitman
July 14, 2008 10:11 AM

I hate seeing these things listed in km. It just seems so much simpler to list distance in miles. Miles was the standard measurement for 400 years in the U.S but some one decided we should go to the British standard during the second half of the last century.
Inches, feet, and yards are more accurate for distance.?????

Snapper
Guest
Snapper
July 14, 2008 10:14 AM

Hey LLDIAZ, things have been clarified. A planet needs to meet 3 criteria:
1. Large enough to form a sphere (near sphere).
2. Orbit the sun
3. Be the dominant object in it’s orbit

Rule #3 is the tough one. None of the dwarf planets have cleared their path of other objects of similar size. Mercury on the other hand has nothing else to share it’s orbit with.

Eric Near Buffalo
Guest
Eric Near Buffalo
July 14, 2008 11:09 AM

I’d like to say that this object is probably the mythical Nibiru finally coming into view.

It’s likely that it’s orbit will accelerate greatly and eventually in December 2012 collide with our planet, rendering our pornography and drugs totally useless.

Joso Roso
Guest
Joso Roso
July 14, 2008 11:57 AM

Makemake?!?!? Come on, we’ve been waiting all this time for a name and they call it Makemake?!?!? sad

Don Alexander
Member
Don Alexander
July 14, 2008 12:22 PM

@ Joso Roso: My thought exactly. “They nicknamed it Easterbunny (which is easier to say than 2005 FY9 or 136472)” – and also easier than Makemake…

\make newname!

@Eric Near Buffalo: I hope that was irony… Otherwise you fail the gravity test.

@Craig Whitman: The “British standard” – if anything, it’s the “French standard” (SI = System Internationale), not to mention the WORLD standard for physics. Doing stuff in inches, yards, miles, pounds etc. is actually the stupid thing…

DannyBoy
Guest
DannyBoy
July 14, 2008 12:34 PM

Pornography and drugs USELESS!!!????

OMG! grin

(Long live planetary designation for plutoids and dwarf planets)

James
Guest
James
July 14, 2008 1:23 PM
To the guy talking about kilometers v. miles: Metric is the international unit of measurement. The fact America doesn’t use it is awful. As for the planet argument, I think we need to move on. The fact you complain about Makemake not being a planet, yet disregard the fact Mars and Jupiter are in the same category, is absolutely bogus. I think the current definition of ‘planet’ is great, in any event. Planets are obviously large enough to be spherical, should orbit the sun (or a star, as we start studying other solar systems), and need to dominate their area of orbit. If all objects that were spherical were called ‘planets,’ we’d have 500 freaking planets. It’s not… Read more »
Laurel Kornfeld
Guest
Laurel Kornfeld
July 14, 2008 9:04 PM
Jorge, I second your thought on seeing no problem with our solar system having 500 planets if that is what it turns out we have. This definition does not even work for our solar system. None of the eight classical planets fully clears its orbit. And a definition that states a dwarf planet is not a planet at all makes no sense. We can correct this by nullifying the IAU resolution that decreed this statement and replace it with one that places dwarf planets as a subcategory of the broader term planet. Dan, not only was the labeling of Pluto as a planet NOT an error; your analogy with Ceres does not even support your argument. 19th century… Read more »
Jorge
Guest
July 14, 2008 3:47 PM
I don’t, and never will, get what is it that freaks some people out so much when that think of having “500 freaking planets”. I much prefer “500 freaking planets” to “8 freaking planets”, provided the definition of what a planet is makes actual sense. Which this one doesn’t. It may work for the Solar System (it remains to be seen if it does; we haven’t found everything out there beyond the ice zone, and we still may find some stuff there able to put this whole “orbit clearing” shebang into question again… and besides, all planetary orbits in the Solar Sistem are ultimately ruled by Jupiter, so dinamically the Boss is the only real planet out there;… Read more »
Iain M. Banks
Guest
Iain M. Banks
July 14, 2008 4:18 PM

Makemake. Have we joined the culture and our governments have not told us?

Darnell Clayton
Member
July 14, 2008 6:39 PM

It looks like an interesting world, but at 50 AU from sunshine it does sound like a pretty lonely planet/dwarf planet.

Regardless of what you call it, who is in favor of sending a robot to visit it? wink

James
Guest
James
July 14, 2008 10:42 PM
Jorge, I understand what you mean about the fear that I portrayed about having 500 planets, and I hope you’ll allow me to correct myself and say that I fear classifying objects with such major differences under the same category, rather than fearing a large number of planets. I also understand what you’re saying about two planet-sized objects revolving around eachother, or some situation that could easily mess up with current definition, and so I’d like to correct myself and say the definition doesn’t work. I’m pretty much in agreement with what Laurel said. I do find it important that we still be sure to separate things from eachother, but, thinking on it, we could end up with… Read more »
DavidV
Guest
DavidV
July 15, 2008 12:56 AM
Another one to the metric/inch debate. Over 30 years ago here in the UK ALL scientiftic teaching, whether from primary school to university was metric – SI units. I now work with customers world wide looking after metal working machines. Almost everyone gets on well with metric measurements. The only exception is a small region (yes it is small on a global scale) called North America. Hopefully this region will catch up with the rest of the world soon and the mistakes associated with measurement confusion will stop. It is not just the odd bit of space kit that goes wrong. Aircraft full of people have failed to reach their destination when pounds and kilogrammes of fuel have… Read more »
Paul Eaton-Jones
Member
July 15, 2008 4:30 AM

Although we here in Briatain have technicially been metric since 1915, I believe, we still use miles, feet and inches as well as pounds and ounces. Horse races are still run in miles and furlongs. The length of a cricket pitch is 22 yards or 1 chain. When I was at school in the 1960’s-70’s we learned about pecks, poles, rods, bushells etc. Kilometers? Phooey!!
Paul.

Dan
Guest
July 15, 2008 12:07 PM
@Laurel (yesterday): I can’t remember anyone calling for Ceres to be re-classified as a planet at any time in the last 150 years – and that it is pretty round was not a big discovery as bodies beyond 1000 km or so are supposed to look that way, thanks to their self-gravity. (The limit for ordinary rocks is actually somewhat smaller than 1000 km, I think.) Let me take you back to August 2006, just before that bizarre “12 planets” proposal was made public (but had been leaked to me already): I asked a number of astronomers and planetary scientists if they could guess which 3 ‘new planets’ that might include, and not one hit on either Ceres… Read more »
Eric Near Buffalo
Guest
Eric Near Buffalo
July 15, 2008 6:34 AM

~~~Don Alexander Says:
July 14th, 2008 at 12:22 pm

@Eric Near Buffalo: I hope that was irony… Otherwise you fail the gravity test.~~~

To think that it was anything other than irony is obsurd. Some people just don’t know that there’s more to life than highs and handjobs.

Jorge
Guest
July 15, 2008 7:22 AM
Laurel, you’re wrong in one thing: the definition does work for our system as we know it now. They came up with an index of “orbit cleansing” that did show a large gap between the 8 big ones and the dwarves and asteroids. They don’t demand that the “neighborhoods” are entirely clean, they just demand that it’s “clean enough”. What’s a neighborhood, though, it totally arbitrary. Ceres’ neighborhood, for instance, is a volume of space much, much larger than Earth’s, including the whole asteroid belt. What’s “clean enough” is also completely arbitrary: they just decided on a number with no physical backing. What’s worse: the notion that a planet, to be a planet, has to clean it’s neighborhood… Read more »
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