IAU Archives

December 29, 2014December 23, 2015 by Tim Reyes

2015: NASA’s Year of the Dwarf Planet

Two spacecraft, Dawn and New Horizon will reach their final objectives in 2015 - Dwarf Planets - Ceres and Pluto. (Credit: NASA, Illustration - T.Reyes)

Together, the space probes Dawn and New Horizons have been in flight for a collective 17 years. One remained close to home and the other departed to parts of the Solar System of which little is known. They now share a common destination in the same year: dwarf planets.

At the time of these NASA probes’ departures, Ceres had just lost its designation as the largest asteroid in our Solar System. Pluto was the ninth planet. Both probes now stand to deliver measures of new data and insight that could spearhead yet another revision of the definition of planet.

A comparison of the trajectories of New Horizon (left) and the Dawn missions (right). (Credit: NASA/JPL, SWRI, Composite- T.Reyes) — A comparison of the trajectories of New Horizons (left) and the Dawn missions (right). (Credit: NASA/JPL, SWRI, Composite- T.Reyes)

Certainly, NASA’s Year of the Dwarf Planet is an unofficial designation and NASA representatives would be quick to emphasize another dozen or more missions that are of importance during the year 2015. However, these two missions could determine the fate of billions or more small bodies just within our galaxy, the Milky Way.

If Ceres and Pluto are studied up close – mission success is never a sure thing – then what is observed could lead to a new, more certain and accepted definition of planet, dwarf planet, and possibly other new definitions.

The New Horizons mission became the first mission of NASA’s New Frontiers program, beginning development in 2001. The probe was launched on January 19, 2006, atop an Atlas V 551 (5 solid rocket boosters plus a third stage). Utilizing more compact and lightweight electronics than its predecessors to the outer planets – Pioneer 10 & 11, and Voyager 1 & 2 – the combination of reduced weight, a powerful launch vehicle, plus a gravity assist from Jupiter has lead to a nine year journey. On December 6, 2014, New Horizons was taken out of hibernation for the last time and now remains powered on until the Pluto encounter.

This "movie" of Pluto and its largest moon, Charon b yNASA's New Horizons spacecraft taken in July 2014 clearly shows that the barycenter -center of mass of the two bodies - resides outside (between) both bodies. The 12 images that make up the movie were taken by the spacecraft’s best telescopic camera – the Long Range Reconnaissance Imager (LORRI) – at distances ranging from about 267 million to 262 million miles (429 million to 422 million kilometers). Charon is orbiting approximately 11,200 miles (about 18,000 kilometers) above Pluto's surface. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute) — This “movie” of Pluto and its largest moon, Charon, by NASA’s New Horizons spacecraft taken in July 2014 clearly shows that the barycenter – the center of mass of the two bodies – resides outside (between) both bodies. The 12 images that make up the movie were taken by the spacecraft’s best telescopic camera – the Long Range Reconnaissance Imager (LORRI) – at distances ranging from about 267 million to 262 million miles (429 million to 422 million kilometers). Charon is orbiting approximately 11,200 miles (about 18,000 kilometers) above Pluto’s surface. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

The arrival date of New Horizon is July 14, 2015. A telescope called the Long Range Reconnaissance Imager (LORRI) has permitted the commencement of observations while still over 240 million kilometers (150 million miles) from Pluto. The first stellar-like images were taken while still in the Asteroid belt in 2006.

Pluto was once the ninth planet of the Solar System. From its discovery in 1930 by Clyde Tombaugh until 2006, it maintained this status. In that latter year, the International Astronomical Union undertook a debate and then a membership vote that redefined what a planet is. The change occurred 8 months after New Horizons’ launch. There were some upset mission scientists, foremost of which was the principal investigator, Dr. Alan Stern, from the Southwest Research Institute in San Antonio, Texas. In a sense, the rug had been pulled from under them.

A gentleman’s battle ensued between opposing protagonists Dr. Stern and Dr. Michael Brown from Caltech. In 2001, Dr. Brown’s research team began to discover Kuiper belt objects (Trans-Neptunian objects) that rivaled the size of Pluto. Pluto suddenly appeared to be one of many small bodies that could likely number in the trillions within just one galaxy – ours. According to Dr. Brown, there could be as many as 200 objects in our Solar System similar to Pluto that, under the old definition, could be defined as planets. Dr. Brown’s work was the straw that broke the camel’s back – that is, it led to the redefinition of planet, and the native of Huntsville, Alabama, went on to write a popular book, How I Killed Pluto and Why It Had It Coming.

Dr. Stern’s story involving Pluto and planetary research is a longer and more circuitous one. Stern was the Executive Director of the Southwest Research Institute’s Space Science and Engineering Division and then accepted the position of Associate Administrator of NASA’s Science Mission Directorate in 2007. Clearly, after a nine year journey, Stern is now fully committed to New Horizons’ close encounter. More descriptions of the two protagonists of the Pluto debate will be included in a follow on story.

Artist’s concept depicting the Dawn spacecraft thrusting with its ion propulsion system as it travels from Vesta (lower right) to Ceres (upper left). The galaxies in the background are part of the Virgo supercluster. Dawn, Vesta and Ceres are currently in the constellation Virgo from the perspective of viewers on Earth. (Image credit: NASA/JPL) — Artist’s concept depicting the Dawn spacecraft thrusting with its ion propulsion system as it travels from Vesta (lower right) to Ceres (upper left). The galaxies in the background are part of the Virgo supercluster. Dawn, Vesta, and Ceres are currently in the constellation Virgo from the perspective of viewers on Earth. (Image credit: NASA/JPL)

The JPL and Orbital Science Corporation developed Dawn space probe began its journey to the main asteroid belt on September 27, 2007. It has used gravity assists and flew by the planet Mars. Dawn spent 14 months surveying Vesta, the 4th largest asteroid of the main belt (assuming Ceres is still considered the largest). While New Horizons has traveled over 30 Astronomical Units (A.U.) – 30 times the distance from the Earth to the Sun – Dawn has remained closer and required reaching a little over 2 A.U. to reach Vesta and now 3 A.U. to reach Ceres.

The Dawn mission had the clear objective of rendezvous and achieving orbit with two asteroids in the main belt between Mars and Jupiter. Dawn was also sent packing the next generation of Ion Propulsion. It has proven its effectiveness very well, having used ion propulsion for the first time to achieve an orbit. Pretty simple, right? Not so fast.

As Dawn was passing critical design reviews during development, the redefinition of planet lofted its second objective – the asteroid 1 Ceres – to a new status. While Pluto was demoted, Ceres was promoted from its scrappy status of biggest of the asteroids – the debris, the leftovers of our solar system’s development – to dwarf planet. Even 4 Vesta is now designated a proto-planet.

Artist rendition of Dawn spacecraft orbiting Vesta(Credit: NASA/JPL-Caltech) — Artist rendition of Dawn spacecraft orbiting Vesta. (Credit: NASA/JPL-Caltech)

So now the stage is set. Dawn will arrive first at a dwarf planet – Ceres – in April. With a small, low gravity body and ion propulsion, the arrival is slow and cautious. If the two missions fair well and achieve their goals, 2015 is likely to become a pivotal year in the debate over the classification of non-stellar objects throughout the universe.

Just days ago, at the American Geophysical Union Conference in San Francisco, Dr. Stern and team described the status and more details of the goals of New Horizons. Since arriving, more moons of Pluto have been discovered. There is the potential that faint rings exist and Pluto may even harbor an interior ocean due to the tidal forces from its largest moon, Charon. And Dawn mission scientists have seen the prospects for Ceres’ change. Not just the status, the latest Hubble images of Ceres is showing bright spots which could be water ice deposits and could also harbor an internal ocean.

The Solar System is becoming a more crowded place. This picture shows the sizes of dwarf planets Pluto, Ceres, Eris, and Makemake as compared to Earth and Earth's Moon, here called "Luna." None of the distances between objects are to scale. (Credit: NASA) — The Solar System is becoming a more crowded place. This picture shows the sizes of dwarf planets Pluto, Ceres, Eris, and Makemake as compared to Earth and Earth’s Moon, here called “Luna.” None of the distances between objects are to scale. (Credit: NASA)

So other NASA missions notwithstanding, this is the year of the dwarf planet. NASA will provide Humanity with its first close encounters with the most numerous of small round – by their self-gravity – bodies in the Universe. They are now called dwarf planets but ask Dr. Stern and company, the public, and many other planetary scientists and you will discover that the jury is still out.

References:

JHU/APL New Horizons Mission Home Page

NASA Dawn Mission Home Page

NameExoWorlds, an IAU Worldwide Contest to Name Alien Planets, Continues Controversy

This artist’s view shows an extrasolar planet orbiting a star (the white spot in the right). Image Credit: IAU/M. Kornmesser/N. Risinger (skysurvey.org)

The International Astronomical Union has unveiled a worldwide contest, NameExoWorlds, which gives the public a role in naming planets and their host stars beyond the solar system.

It’s the latest chapter in a years-long controversy over how celestial objects, including exoplanets, are classified and named.

Although the IAU has presided over the long process of naming astronomical objects for nearly a century, until last year they didn’t feel the need to include exoplanets on this long list.

As late as March 2013, the IAU’s official word on naming exoplanets was: “The IAU sees no need and has no plan to assign names to these objects at the present stage of our knowledge.” Since there was seemingly going to be so many exoplanets, the IAU saw it too difficult to name them all.

Other organizations, however, such as the SETI institute and the space company Uwingu leapt at the opportunity to engage the public in providing names for exoplanets. Their endeavors have been widely popular with the general public, but generated discussion about how ‘official’ the names would be.

The IAU issued a later statement in April 2014 (which Universe Today covered with vigor) and claimed that these two campaigns had no bearing on the official naming process. By August 2014, the IAU had introduced new rules for naming exoplanets, drastically changing their stance and surprising many.

Now in partnership with Zooniverse, a citizen-science organization, the IAU has drawn up a list of 305 well-characterized exoplanets in 206 solar systems. Starting in September, astronomy organizations can register for the opportunity to select planets for naming.

In October, the IAU plans to ask the registered organizations to vote for the 20 to 30 worlds on the list that they want to name. The exact number will depend on the number of registered groups. In December, those groups can propose names for the worlds that get the most votes. Groups can only propose names in accordance with the following set of rules. A name must be:

— 16 characters or less in length

— Preferably one word

— Pronounceable (in some language)

— Non-offensive

— Not too similar to an existing name of an astronomical object

Starting in March 2015, the list of proposed names will be put up to an Internet vote. The winners will be validated by the IAU, and announced during a ceremony at the IAU General Assembly in Honolulu in August 2015.

The popular name for a given exoplanet won’t replace the scientific name. But it will carry the IAU seal of approval.

Astronomer Alan Stern, principal investigator of the New Horizons mission to Pluto and CEO of Uwingu told Universe Today’s Senior Editor, Nancy Atkinson, that he was not surprised by the IAU’s new statement. “To my eye though, it’s just more IAU elitism, they can’t seem to get out of their elitist rut thinking they own the Universe.”

“Uwingu’s model is in our view far superior — people can directly name planets around other stars, with no one having to approve the choices,” Stern continued. “With 100 billion plus planets in the galaxy, why bother with committees of elites telling people what they do and don’t approve of?”

If nothing else, the controversy has sparked multiple venues to name exoplanets and more importantly learn about these alien worlds.

August 16, 2013December 29, 2015 by Fraser Cain

Weekly Space Hangout – Aug. 16, 2013

Like your space news, but you just can’t handle reading any more? Then watch our Weekly Space Hangout, where we give you a rundown of all the big space news stories that broke this week.

Host: Fraser Cain

Panel: Brian Koberlein, David Dickinson, Nancy Atkinson, Nicole Gugliucci

Stories:
CIA Comes Clean About Area 51
Elon Musk’s Hyperloop
Space Fence Shut Down
Magnetar Discovered Near the Galactic Core
IAU Updates Their Naming Policy
Bright Nova in Delphinus

We record the Weekly Space Hangout every Friday at 12 pm Pacific / 3 pm Eastern as a live Google+ Hangout on Air. Join us live on YouTube, or you can listen to the audio after the fact on the 365 Days of Astronomy Podcast.

August 15, 2013December 23, 2015 by Nancy Atkinson

IAU Revises Their Stance on Public Involvement in Naming of Exoplanets and Moons

Artistic representations of the only known planets around other stars (exoplanets) with any possibility to support life as we know it. Credit: Planetary Habitability Laboratory, University of Puerto Rico, Arecibo.

The International Astronomical Union issued a statement on August 14, 2013 that they have changed their official stance on two things: 1. assigning popular names to the numerous extrasolar planets being discovered, and 2. allowing the public to be involved in that naming process.

“It is therefore in line with a long-established global tradition and experience that the IAU fully supports the involvement of the general public, whether directly or through an independent organised vote, in the naming of planetary satellites, newly discovered planets and their host stars,” the online statement said.

This new stance came as a surprise to many.

“I was surprised by the IAU statement encouraging the general public input on naming astronomical objects,” said Professor Abel Mendez, director of the Planetary Habitability Laboratory at the University of Puerto Rico, in an email to Universe Today. “This is certainly something good. …So there is now a public naming procedure that includes the IAU validation but this does not exclude any other non-IAU public naming campaigns.”

As recently as late March, 2013, the IAU’s official word on naming exoplanets was, “the IAU sees no need and has no plan to assign names to these objects at the present stage of our knowledge.”

Their rationale was since there is seemingly going to be so many exoplanets, it will be difficult to name them all.

But then, on about March 24, the IAU added this to their website:

“…the IAU greatly appreciates and wishes to acknowledge the increasing interest from the general public in being more closely involved in the discovery and understanding of our Universe. As a result in 2013 the IAU Commission 53 Extrasolar Planets and other IAU members will be consulted on the topic of having popular names for exoplanets, and the results will be made public on the IAU website.”

Artistic rendition of a sunset view from the perspective of an imagined Earth-like moon orbiting the giant planet, PH2 b. Image Credit: H. Giguere, M. Giguere/Yale University — Artistic rendition of a sunset view
from the perspective of an imagined Earth-like moon orbiting the giant planet, PH2 b. Image Credit: H. Giguere, M. Giguere/Yale University

This new decision follows a line of events earlier this year where the SETI Institute and the space company Uwingu organized their own campaigns/contests for creating popular names of objects in space instead of the rather clinical, scientific names currently assigned to planets, such as HD 41004 Ab. Both events were wildly popular with the general public, but generated discussion about how “official” the names would be. The IAU issued a statement regarding the contests saying that while they welcomed the public’s interest in being involved in recent discoveries, as far as they are concerned, the IAU has the last word. Additionally, they were against “selling” names (Uwingu charged a fee to suggest a name and to vote as a fundraiser for space research.)

“In the light of recent events, where the possibility of buying the rights to name exoplanets has been advertised, the International Astronomical Union (IAU) wishes to inform the public that such schemes have no bearing on the official naming process. The IAU… would like to strongly stress the importance of having a unified naming procedure,” said the April 12, 2013 statement issued by the IAU.

The IAU’s new rules allow for individuals to suggest names of exoplanets and planetary satellites (moons) via email to the IAU (Click here for email address).

Public naming campaigns are also “sanctioned” given they follow a set of rules:

1. Prior to any public naming initiative, often a vote (hereafter “the process”), the IAU should be contacted from the start by Letter of Intent sent to the IAU General Secretary;
2. The process should be submitted in the form of a proposal to the IAU by an organization. Scientists or science communicators may be involved in the process;
3. The organization should list its legal or official representatives and its goals, and explain the reasons for initiating the process for naming a particular object or set of objects;
4. The process cannot request nor make reference to any revenues, for whatever purpose;
5. The process must guarantee a wide international participation;
6. The public names proposed (whether by individuals or in a naming campaign)should follow the naming rules and restrictions adopted for Minor Bodies of the Solar System, by the IAU and by the Minor Planet Center (see here and here
for more details.

Among other rules are that proposed names should be 16 characters or less in length, pronounceable in as many languages as possible, non-offensive in any language or culture, and that names of individuals, places or events principally known for political or military activities are unsuitable.

Also, the names must have the formal agreement of the discoverers.

The new statement also has its critics. People joked on Twitter this morning whether the name of our neighboring planet Mars, named for the god of war, will have to be changed due to the new restrictions on military nomenclature.

Astronomer Alan Stern, principal investigator of the New Horizons mission to Pluto and CEO of Uwingu said he was actually not surprised at the IAU’s new statement.

“Fundamentally it’s still about the public being subservient to IAU committees that pass on recommendations,” he said via an email response to Universe Today. “Old school. Why should the IAU be a traffic cop?”

Stern also said the new statement has several contradictions from the statement the IUA put out on April 12 of this year, such as that “these [naming]campaigns have no bearing on the official naming process — they will not lead to an officially-recognised exoplanet name, despite the price paid or the number of votes accrued.” It now would appear that contests that follow the IAU’s rules are OK.

Stern said he has received letters and emails of support from other astronomers, particularly on the “no revenue” provision, noting how astronomy publications and planetariums charge money for their magazines and sky shows.

“If they can do it, why can’t Uwingu — especially since Uwingu’s revenue is used (at least in part) to further the IAU’s own goals, namely, to advance the science of astronomy, and the public’s understanding of it, worldwide?,” Stern quoted one email he received.

Also, the April statement from the IAU said they were the single arbiter of the naming process of celestial objects, while the new August statement says, “The IAU does not consider itself as having a monopoly on the naming of celestial objects— anyone can in theory adopt names the way they choose.”

The statement goes on, “However, given the publicity and emotional investment associated with these discoveries, worldwide recognition is important and the IAU offers its unique experience for the benefit of a successful public naming process (which must remain distinct, as in the past, from the scientific designation issues).”

Since this is a public debate about the public’s involvement in providing popular names for astronomical objects, please add your thoughts in the comments.

April 12, 2013December 23, 2015 by Nancy Atkinson

IAU Issues Response To Uwingu’s Exoplanet Naming Campaign

An exoplanet seen from its moon (artist's impression). Via the IAU.

Given the popularity of the recent contest by Uwingu to suggest names for the closest known exoplanet to Earth (officially named Alpha Centauri Bb or ACBb for short), the International Astronomical Union has issued a statement about their stance on the “official” naming process. The IAU says that while they welcome the public’s interest in being involved in recent discoveries, as far as they are concerned, the IAU has the last word.

Scientist Alan Stern, principal investigator of the New Horizons mission to Pluto and CEO Uwingu told Universe Today that he thinks the IAU should side with democracy instead of elitism.

“I think it is diminishing that the IAU is holding onto their claim that they own the Universe,” he said via phone after reviewing the IAU’s statement. “This is like some 15th century European academic club claiming that since Columbus discovered America, they own all the naming rights. That’s BS.”

While the IAU provides official names for stars and planetary bodies in our Solar System, the IAU’s official stance on naming exoplanets has been that since there is seemingly going to be so many of them, (over 800 have been discovered so far) that it will be difficult to name them all. They’ve said the consensus among IAU scientists was that they had no interest in naming exoplanets.

However, they recently added a few sentences on their website that “the IAU greatly appreciates and wishes to acknowledge the increasing interest from the general public in being more closely involved in the discovery and understanding of our Universe. As a result in 2013 the IAU Commission 53 Extrasolar Planets and other IAU members will be consulted on the topic of having popular names for exoplanets, and the results will be made public on the IAU website.”

Stern thinks the IAU’s current stance on naming exoplanets is tactical mistake. “The taxpaying public pays for all the exploration that the IAU members are doing, but the IAU is making an attempt to limit the public’s involvement in something that the public clearly likes to do,” he said. “As an astronomer, that’s my view.”

Uwingu, a startup company that is using out-of-the-box ideas to raise funds for space exploration and science, started an exoplanet naming contest last fall, and the contest to provide a better, “snappier” name for ACBb was started in March, 2013.

Stern knew going into this that the names wouldn’t officially be approved by the International Astronomical Union, but said they will be similar to the names given to features on Mars by the mission science teams (such as Mt. Sharp on Mars –the IAU-approved name is Aeolis Mons) or even like Pike’s Peak, a mountain in Colorado which was named by the public, in a way, as early settlers started calling it that, and it soon became the only name people recognized.

“This should be the wave of the future for planets and there’s no reason for the public not to get involved,” Stern said.

In today’s statement, the IAU said the “certificates” people receive after suggesting a name in Uwingu’s contest are “misleading, as these campaigns have no bearing on the official naming process — they will not lead to an officially-recognized exoplanet name, despite the price paid or the number of votes accrued.”

The IAU conceded that while exoplanet names such as 16 Cygni Bb or HD 41004 Ab may seem boring compared to the names of planets in our own Solar System, “the vast number of objects in our Universe — galaxies, stars, and planets to name just a few — means that a clear and systematic system for naming these objects is vital. Any naming system is a scientific issue that must also work across different languages and cultures in order to support collaborative worldwide research and avoid confusion.”

And to make that possible, the IAU should act as a single arbiter of the naming process, they said.

“As an international scientific organization, [the IAU] dissociates itself entirely from the commercial practice of selling names of planets, stars or or even “real estate” on other planets or moons. These practices will not be recognized by the IAU and their alternative naming schemes cannot be adopted.”

Information about Alpha Centauri Bb. Information about Alpha Centauri Bb. Credit: Planetary Habitability Laboratory/University of Puerto Rico/Arecibo

However, several astronomers, including Xavier Dumusque, the lead author of the paper that announced the discovery of ACBb has said they like the idea of having the public involved in naming the exoplanets.

“I would definitively endorse the name for public outreach and lectures,” Dumusque told Alan Boyle of NBC’s Cosmic Log. “In astronomy, we have some chance to be able to make people dream, by showing a wonderful picture, by discovering new worlds. If someone is interested in astronomy, he should not face troubles to understand all the nomenclature. Therefore, giving memorable names for planets is one way to get more people interested in our wonderful research.”

Moonwalker Buzz Aldrin also has been actively participating in the contest and suggested “Tiber” as the name for ACBb. Aldrin is the co-author of a 1977 sci-fi novel titled “Encounter With Tiber.”

IAU’s reticence in naming exoplanets seems to come from the huge bulk of names that will be required. But that’s where Uwingu’s crowd sourcing idea seems to fit the need, and a sort of compromise would be that the public could come up with the names as suggestions in Uwingu’s “baby book” of names, and the IAU would assign the “official” names from the list provided by the public.

If nothing else, Uwingu’s concept has shown how interested the public is in exoplanets and hopefully has given the IAU the kick in the pants needed to possibly consider naming them.

If you’re interested in suggesting names for ACBb, be quick, as the Uwingu contest ends on April 15.

February 25, 2013April 26, 2016 by Jason Major

Pluto May Soon Have a Moon Named Vulcan (Thanks to William Shatner)

These may soon be the names of Pluto's family of moons (Hubble image: NASA, ESA and M. Showalter/SETI)

The votes have been tallied and the results are in from the SETI Institute’s Pluto Rocks Poll: “Vulcan” and “Cerberus” have come out on top for names for Pluto’s most recently-discovered moons, P4 and P5.

After 450,324 votes cast over the past two weeks, Vulcan is the clear winner with a landslide 174,062 votes… due in no small part to a little Twitter intervention by Mr. William Shatner, I’m sure.

In other words… yes, the Trekkies have won.

During a Google+ Hangout today, SETI Institute senior scientist Mark Showalter — who discovered the moons and opened up the poll — talked with SETI astronomer Franck Marchis and MSNBC’s Alan Boyle about the voting results. Showalter admitted that he wasn’t quite sure how well the whole internet poll thing would work out, but he’s pleased with the results.

“I had no idea what to expect,” said Showalter. “As we all know the internet can be an unruly place… but by and large this process has gone very smoothly. I feel the results are fair.”

As far as having a name from the Star Trek universe be used for an actual astronomical object?

“Vulcan works,” Showalter said. “He’s got a family tie to the whole story. Pluto and Zeus were brothers, and Vulcan is a son of Pluto.”

And what can you say when even Mr. Spock agrees?

The other winning name, Cerberus, is currently used for an asteroid. So because the IAU typically tries to avoid confusion with two objects sharing the same exact name, Showalter said he will use the Greek version of the spelling: Kerberos.

Cerberus (or Kerberos) is the name of the giant three-headed dog that guards the gates to the underworld in Greek mythology.

Now that the international public has spoken, the next step will be to submit these names to the International Astronomical Union for official approval, a process that could take 1–2 months.

(Although who knows… maybe Bill can help move that process along as well?)

Read more about the names on the Pluto Rocks ballot here, and watch the full recorded Google+ Hangout below:

August 14, 2012December 23, 2015 by Jason Major

“The Hobbit” Author Gets a Crater on Mercury

Here’s a little something to please fans of space, art and fantasy alike (and those who enjoy all three): on August 6 the International Astronomical Union approved names for 9 craters on Mercury, one of which is named for J.R.R. Tolkien, revered author of The Hobbit and The Lord of the Rings (among other seminal fantasy works.)

The crater Tolkien is approximately 30 miles (48 km) in diameter. All 9 newly-named craters are located in Mercury’s north polar region and exhibit radar evidence of water ice hidden in their shadowy pocketses.

IAU procedure for craters on Mercury has them named after “deceased artists, musicians, painters, and authors who have made outstanding or fundamental contributions to their field and have been recognized as art historically significant figures for more than 50 years.” Find out who all 9 new craters are named for after the jump:

Egonu, for Uzo Egonu (1931-1996), a Nigerian-born painter who at 13 was sent to England to study art, first at a private school in Norfolk and later at the Camberwell School of Arts and Crafts. Exile, alienation, and the pain of displaced peoples were recurrent themes in his work.

Gaudí, after Antoni Gaudí (1852-1926), a Spanish architect whose work concentrated largely on the Catalan capital of Barcelona. He was very skilled with ceramics, stained glass, wrought-iron forging, and carpentry and integrated these crafts into his architecture.

Kandinsky, for Wassily Kandinsky (1866-1944), a Russian painter and art theorist credited with painting the first purely abstract works.

Petronius, for Titus Petronius (c. AD 27-66), a Roman courtier during the reign of Nero. He is generally believed to be the author of the Satyricon, a satirical novel believed to have been written during the Neronian era.

Prokofiev, for Sergei Prokofiev (1891-1953), a Russian composer, pianist, and conductor who is considered one of the major composers of the 20th century. His best-known works include the ballet Romeo and Juliet — from which “Dance of the Knights” is taken — and Peter and the Wolf.

Tolkien, for John Ronald Reuel (J. R. R.) Tolkien (1892-1973), an English writer, poet, philologist, and university professor, best known as the author of the classic fantasy novels The Hobbit and The Lord of the Rings.

Tryggvadóttir, for Nina Tryggvadóttir (1913-1968), one of Iceland’s most important abstract expressionist artists and one of very few Icelandic female artists of her generation. She primarily worked in painting, but she also created collages, stained glass work, and mosaics.

Qiu Ying, for Shifu Qiu Ying (1494-1552), a Chinese painter who specialized in the gongbi brush technique, a careful realist method in Chinese painting. He is regarded as one of the Four Great Masters of the Ming Dynasty.

Yoshikawa, for Eiji Yoshikawa (1892-1962), a Japanese historical novelist best known for his revisions of older classics including The Tale of the Heike, Tale of Genji, Outlaws of the Marsh, and Romance of the Three Kingdoms.

“These designations expand the opportunities to recognize the contributions to the arts by the most creative individuals from many cultures and eras. The names of those individuals are now linked in perpetuity to the innermost planet.”

– Sean Solomon, MESSENGER Principal Investigator

The craters were imaged by NASA’s MESSENGER spacecraft, currently in extended mission around Mercury. Learn more about the preciousss MESSENGER mission here. (Gollum! Gollum!)

Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

May 14, 2012December 23, 2015 by Jason Major

Warhol Crater Gets Its 15 Minutes of Fame

Warhol crater, one of 23 recently named craters on Mercury

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As pop art icon Andy Warhol said, “In the future everyone will be famous for fifteen minutes,” and so here’s an image of the crater on Mercury that now bears his name, set up in the style of one of his multicolored silkscreens.

Warhol is one of 23 craters on Mercury to be recently approved for names by the International Astronomical Union (IAU), joining other notable artists, authors and musicians like Gustav Holst, Rene Magritte and Dr. Seuss who now have craters named in their honor on the first rock from the Sun.

95 km (59 miles) in diameter, Warhol crater features a large, elongated central peak, stepped walls and many of the curious erosions known as hollows.

The original image, seen at top left, was acquired by NASA’s MESSENGER spacecraft on October 21, 2011, using its Wide-Angle Camera Mercury Dual Imaging System (MDIS) instrument.

With the new list of 23 named craters, there are now 76 officially (and artistically) titled craters on Mercury since MESSENGER’s first pass of the planet in January 2008.

See the original release by the MESSENGER mission team here.

“I’m bored with that line. I never use it anymore. My new line is “In 15 minutes everybody will be famous.”
– Andy Warhol (1928 – 1987)

Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

April 24, 2011December 24, 2015 by Jason Major

More Surprises From Pluto

Artist's illustration of Pluto's surface. Credit: NASA

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Ah, Pluto. Seems every time we think we’ve got it figured out, it has a new surprise to throw at us.

First spotted in 1930 by a young Clyde Tombaugh, for 76 years it enjoyed a comfortable position as the solar system’s most distant planet. Then a controversial decision in 2006 by the International Astronomical Union, spurred by suggestions from astronomer (and self-confessed “planet-killer”) Mike Brown*, relegated Pluto to a new class of worlds called “dwarf planets”. Not quite planets and not quite asteroids, dwarf planets cannot entirely clear their orbital path with their own gravitational force and thus miss out on full planetary status. Besides immediately making a lot of science textbooks obsolete and rendering the handy mnemonic “My Very Eager Mother Just Served Us Nine Pies” irrelevant (or at least confusing), the decision angered many people around the world, both in and out of the scientific community. Pluto is a planet, they said, it always has been and always will be! Save Pluto! the schoolkids wrote in crayon to planetarium directors. The world all of a sudden realized how much people liked having Pluto as the “last” planet, and didn’t want to see it demoted by decision, especially a highly contested one.

Yet as it turns out, Pluto really may not be a planet after all.

It may be a comet.

But…that’s getting ahead of ourselves. First things first.

Discovery data showing carbon monoxide spectrum. Credit: J.S. Greaves / Joint Astronomy Centre.

Recent discoveries by a UK team of astronomers points to the presence of carbon monoxide in Pluto’s atmosphere. Yes, Pluto has an atmosphere; astronomers have known about it since 1988. At first assumed to be about 100km thick, it was later estimated to extend out about 1500km and be composed of methane gas and nitrogen. This gas would expand from the planet’s – er, dwarf planet’s – surface as it came closer to the Sun during the course of its eccentric 248-year orbit and then freeze back onto the surface as it moved further away. The new findings from the University of St Andrews team, made by observations with the James Clerk Maxwell telescope in Hawaii, identify an even thicker atmosphere containing carbon monoxide that extends over 3000 km, reaching nearly halfway to Pluto’s largest moon, Charon.

It’s possible that this carbon monoxide atmosphere may have expanded outwards from Pluto, especially in the years since 1989 when it made the closest approach to the Sun in its orbit. Surface heating (and the term “heating” is used scientifically here…remember, at around -240ºC (-400ºF) Pluto would seem anything but balmy to us!) by the Sun’s radiation would have warmed the surface and expelled these gases outwards. This also coincides with observations made by the Hubble Space Telescope over the course of four years, which revealed varying patterns of dark and light areas on Pluto’s surface – possibly caused by the thawing of frozen areas that shift and reveal lighter surface material below.

“Seeing such an example of extra-terrestrial climate-change is fascinating. This cold simple atmosphere that is strongly driven by the heat from the Sun could give us important clues to how some of the basic physics works, and act as a contrasting test-bed to help us better understand the Earth’s atmosphere.”

– Dr. Jane Greaves, Team Leader

In fact, carbon monoxide may be the key to why Pluto even still has an atmosphere. Unlike methane, which is a greenhouse gas, carbon monoxide acts as a coolant; it may be keeping Pluto’s fragile atmosphere from heating up too much and escaping into space entirely! Over the decades and centuries that it takes for Pluto to complete a single year, the balance between these two gases must be extremely precise.

So here we have Pluto exhibiting an expanding atmosphere of thawing expelled gas as it gets closer to the Sun in an elliptical, eccentric orbit. (Sound familiar?) And now there’s another unusual, un-planet-like feature that’s being put on the table: Pluto may have a tail.

Actually this is an elaboration of the research results coming from the same team at the University of St Andrews. The additional element here is a tiny redshift detected in the carbon monoxide signature, indicating that it is moving away from us in an unusual way. It’s possible that this could be caused by the top layers of Pluto’s atmosphere – where the carbon monoxide resides – being blown back by the solar wind into, literally, a tail.

That sounds an awful lot, to this particular astronomy reporter anyway, like a comet.

Just saying.

Anyway, regardless of what Pluto is or isn’t, will be called or used to be called, there’s no denying that it is a fascinating little world that deserves our attention. (And it will be getting plenty of that come July 2015 when the New Horizons spacecraft swings by for a visit!) I’m sure there’s no one here who would argue that fact.

New Horizons’ upcoming visit will surely answer many questions about Pluto – whatever it is – and most likely raise even more.

Artist's impression of Pluto's huge atmosphere of carbon monoxide.Credit:P.A.S. Cruickshank.

The new discovery was presented by team leader Dr. Jane Greaves on Wednesday, April 20 at the National Astronomy Meeting in Wales.

Article reference: arxiv.org/abs/1104.3014: Discovery Of Carbon Monoxide In The Upper Atmosphere Of Pluto

*No disrespect to Mr. Brown intended…he was just performing science as he saw fit!

August 22, 2009December 24, 2015 by Abby Cessna

What Are Planets?

The mysterious Eris and moons. Credit: NASA

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Throughout history, the definition of what a planet is has changed and meant various things at the same time depending on who was defining it. Objects like the Sun, which we would now scoff at defining as a planet, was once considered just that, and so was the Moon. Ceres, discovered in 1801, was originally thought to be a planet until astronomer discovered Pallas that has a similar orbit. Astronomers, even using the technology of their time, were able to tell that these objects were not planets. The famous astronomer Sir William Herschel suggested the name “asteroids” which stuck. Asteroids were then accepted as a distinct category.

Several years ago, you may have said that a planet is one of the nine large celestial bodies that orbits the Sun. However, new technology, which made the discovery of many new celestial bodies in various regions, such as the Kuiper Belt, possible also made determining what a planet is more difficult. While a number of people suggested various definitions over the years, none of them were widely accepted.

The issue came to a head in 2005 when an object larger than Pluto is was discovered beyond the Kuiper Belt. This object, which is now called Eris, was a source of division among many. Some astronomers wanted Eris to be the tenth planet while others considered it to be just another asteroid, despite the fact that it is larger than Pluto is. The International Astronomical Union (IAU), which usually resolves disputes like this, met in 2005 at a conference, but despite debating the issue, they did not come up with an agreed upon definition. The matter was resumed in summer of 2006 at the next IAU conference.

In August 2006, the IAU finally agreed upon a definition for a planet. The IAU’s official definition was, “A planet is a celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighborhood around its orbit.” An object that has cleared the neighborhood of its orbit is of sufficient size for its gravity to force other objects of similar size out of its orbit. In addition to defining what a planet is, the IAU also created a new category of dwarf planets, which Pluto was reclassified as, and Eris and several other objects were also put in that category. The definition has had severe opposition, especially with many people angry at the demotion of Pluto.

Universe Today has articles on dwarf planets and planet.

For more information, try an overview of the planets and what is a planet.

Astronomy Cast has episodes on all the planets including Venus.