Tenth Planet Discovered? Now only another "Dwarf Planet"

Originally named Xena, but now named Eris


Astronomers at Palomar Observatory Discover a large object beyond Pluto


Discovery images of the new planet. The three images were taken 1 1/2 hours apart on the night of October 21st, 2003.
The planet can be seen very slowly moving across the sky over the course of 3 hours.

Read the scientific paper describing the discovery of 2003 UB313

The planet, with the current temporary (and unfortunate) name 2003UB313, was discovered in an ongoing survey at Palomar Observatory's Samuel Oschin telescope by astronomers Mike Brown (Caltech), Chad Trujillo (Gemini Observatory), and David Rabinowitz (Yale University).

The permanent name of the new planet is currently in limbo while committees decide its fate. For those speculating that the name will be "Lila" based on the web site name I must warn you that that is really just a sentimental dad's early-morning-after-no-sleep naming of a web site for his three week old daughter and one should not take it too seriously! Reports that the name is to be "Xena" come from a misreading of an article in the New York Times in which we discuss our internal code names that we use before we publically announce the existence of the objects. Other code names have been "Santa" (2003 EL61), "Easterbunny" (2005 FY9) and "Flying Dutchman" (Sedna). Those are not intended to stick, though we have become fond of all of them.

Information here will be continually updated as we learn more about this new tenth planet.

Artists concept of the view from the planet, looking back towards the distant sun. Credit: Robert Hurt (IPAC)

What is it?

This new planet (see "What makes a planet?" below) is the largest object found in orbit around the sun since the discovery of Neptune and its moon Triton in 1846. It is larger than Pluto, discovered in 1930. Like Pluto, the new planet is a member of the Kuiper belt, a swarm of icy bodies beyond Neptune in orbit around the sun. Until this discovery Pluto was frequently described as "the largest Kuiper belt object" in addition to being called a planet. Pluto is now the second largest Kuiper belt object, while this is the largest currently known.

Where is it?

The new planet is the most distant object ever seen in orbit around the sun, even more distant than Sedna, the planetoid discovered almost 2 years ago. It is almost 10 billion miles from the sun and more than 3 times more distant than the next closest planet, Pluto and takes more than twice as long to orbit the sun as Pluto.

A view of the solar system from the north down. The four circles show the orbits of Jupiter, Saturn, Uranus, and Neptune. The yellow dot in the center is the sun. The earth, if it were shown, would be inside the yellow dot representing the sun. The orbits of the two outermost planets, along with their current positions, are also shown. If you are worried because the sun appears to not be the focus of the orbital ellipse you are very observant! But it is just a projection effect. The see the full 3D orbit go to this very nice web page

At the time of the announcement (late July 2005), the new planet can be seen high in the morning sky a few hours before the sun comes up in the constellation Cetus. The planet can be seen using very high-end amateur equipment, but you need to know where to look. The best way to find precise coordinates (of this planet, or any other body in the solar system) is with JPL's horizons system. Click on "select target" and then enter "2003 UB313" under small (!) bodies.

The orbit of the new planet is even more eccentric than that of Pluto. Pluto moves from 30 to 50 times the sun-earth distance over its 250 year orbit, while the new planet moves from 38 to 97 times the sun-earth distance over its 560 year orbit.

How big is it?

Usually when we first discover distant objects in the outer solar system we don't know for sure how large they are. Why not? Because all we see is a dot of light, like the top of the page. This dot of light is sunlight reflected off the surface of the planet (interestingly the sunlight takes almost a day to get out to the planet, reflect off of it, and get back to the earth!), but we don't know if the object is bright because it is large or if it is bright because it is highly reflective or both. In the case of the new planet, however, we know that even if it is extremely reflective (like fresh snow, for example) it still cannot be as bright as it is unless it is bigger than Pluto. Thus while we don't know for certain the precise size, we know for certain that it is bigger than Pluto. Here are some interesting guesses to how big it might be, based on what the surface is like:

Type of surface

Amount of light reflected

inferred diameter of planet

fraction of Pluto's size

nothing known
2210 km
fresh snow on earth
2330 km
average antarctica
2475 km
2860 km
(based on the similarity to Pluto of the spectrum [see below]
this is our best guess as to the size)
Charon (Pluto's moon)
3550 km

Spitzer Space Telescope observations are often the best way to find the size of objects in the outer solar system. The Spitzer telescope measures the amount of heat coming from an object. If we wanted to measure the size of a fire, for example, we could do it by measuring the total amount of heat coming from the fire. The temperature of the flames in a match and a bonfire are essentially the same, but a bonfire emits much more heat because it is much bigger. The same is true of distant planets. Because we know how far away the planet is we have a pretty good idea of the surface temperature (a frosty 405 degrees below zero!), thus when we measure the total heat we can tell how big the object is.
Though we tried earlier to measure the size using Spitzer, those observations failed due to human error which caused the telescope to point in the wrong direction. The Spitzer Space Telescope rarely makes such errors, but these observations were extremely unusual in that they were of a moving object whose position could not be obtained from pubically available web sites at JPL (since JPL didn't yet know of the existence of the object). Instead, a string of human interaction had to occur between our [correct] submission of the orbital elements and the final pointing of the telescope. Somewhere in this string of interactions a mistake was made. Two other Kuiper belt objects (2003 EL61 and 2005 FY9) were observed in the same manner at the same time and the observations proceeded without a glitch, leading us to initially assume that the 2003 UB313 observations were correctly pointed also. The mistake was caught by one of the many extremely careful members of the Spitzer Science Center. As soon as the mistake was caught new observations were scheduled and safeguards were put into place to prevent such an occurence again. Spitzer will again attempt to observe 2003 UB313 at the end of the month.

In the meantime, we are attempting observing from the 30-meter IRAM telescope. This telescope, like Spitzer, measures the heat output. But IRAM measures the heat output in a region of the spectrum where much less heat is output. Nonetheless we have high hopes that these observations will succeed. The combination of Spitzer and IRAM will be especially powerful.

Yet another step to try to measure the size will be to observe the planet with the Hubble Space Telescope and see if we can do some very careful analysis to measure the size in a similar manner as we did for the planetoid Quaoar. These observations are already scheduled and will be taking place shortly, though the observations are optimzed for detection of satellite rather than size measurement. We are attempting to secure observations optimized for size measurement.

What is the new planet made out of?
We study the composition of distant objects by looking at sunlight reflected off of them. The sunlight reflected off the surface of the earth, for example, shows distinct signatures of the oxygen in earth's atmosphere, of photosynthetic plants, and of abundant water, among other things. We have been using the Gemini Observatory on Mauna Kea, Hawaii to study the light reflected from the surface of the new planet, and have found that the planet looks remarkably similar to Pluto. A comparison of the two is shown below, where we show the amount of sunlight reflected in near infrared light. This type of light, just beyond what is visible to the human eye, is most sensitive to the types of ices expected on surfaces in the outer solar system.

The plot above compares the amount of infrared sunlight of different colors ("wavelength") reflected from the new planet with the amount of sunlight reflected from Pluto. The dips in the amount of sunlight, indicated with arrows, are a characteristic signature of a surface covered with solid frozen methane. Both Pluto and the new planet show these signatures. At the very low temperatures of Pluto and the new planet, methane, which is in gaseous form on the earth, is frozen solid. The interior of the planet, like the interior of Pluto, is likely a mixture of rock and ice.

Pluto and the new planet are not completely identical, however. While Pluto's surface is moderately red, the new planet appears almost gray. We are only now beginning to try to understand why the colors differ so.

Pluto and the new planet are unlike the other 8 planets. Mercury, Venus, Earth, and Mars are medium-sized rocky bodies which we call terrestrial planets. Jupiter, Saturn, Uranus, and Neptune are much larger and called giant planets. All of these planets are on essentially circular orbits in a thin disk orbiting around the sun. The two distant planets are a different type entirely. Both are made of ice and rock, are on very eccentric orbits, and have their orbits tilted with respect to the rest of the planets. The new planet is tilted an amazing 45 degrees away from the rest of the planets!

How was the new planet found?

We have been conducting an ongoing survey of the outer solar system using the Palomar QUEST camera and the Samuel Oschin Telescope at Palomar Observatory in Southern California. This survey has been operating since the fall of 2001, with the switch to the QUEST camera happening in the summer of 2003. To date we have found around 80 bright Kuiper belt objects.
To find objects, we take three pictures of a small region of the night sky over three hours and look for something that moves. The many billions of stars and galaxies visible in the sky appear stationary, while satellites, planets, asteroids, and comets appear to move. The image below shows the three frames taken the night of October 21st, 2003 where we found the new planet. Can you find the moving object?

The area of sky show here is approximately 0.015% of the amount of sky that we look at every night, but even though we survey vast regions of the sky per night, it is still going to take us about 5 years to look at all of the sky visible from Palomar Observatory.

Happily for us (and our families) much of the work is done by computers. The telescope is robotically controlled and sends its data to Pasadena every morning where it is searched by a bank of 10 computers at Caltech. Each morning the computers find approximately 100 potentially-moving objects that a human has to look at. The vast majority are some flaw in the camera and are not real solar system objects, but, occasionally, as seen above, a real object makes its presence known.

Because the new planet is so far away it is moving slower than most of the objects that we find. It is moving so slowly, in fact, that our computers didn't notice it the first time around! We began a special reanalysis a year later to specifically look for very distant objects. This reanalysis found the new planet at 11:20AM PST on January 5th 2005, almost 1 1/2 years after the initial data were obtained. Note that initial reports suggested that the discovery date was January 8th. We apologize for the mistake; it was caused because of the craziness surrounding the first day of announcement. We didn't have time to check our notes and apparently our memories are not as good as they used to be.

What is the real name going to be?
When a new object is discovered the International Astronomical Union (IAU) gives it a temporary designation based on the date it was first seen. Thus 2003 UB313 can be decoded to tell you that the data from which the object was discovered was obtained in the second half of October 2003. Next, the discoverers propose a permanent name. We have proposed such a name and are eagerly awaiting the ruling from the IAU, which we hope will come soon. Until that time, however, we are obligated to keep our name to ourselves. But we are free to discuss naming philosophies!

As with everything else in this universe, there are official rules whereby a new body must be named. Interestingly, it is not entirely clear which rules this new planet falls under, since no one expected to find new planets so no rules actually exist. If the object falls under the rules for other Kuiper belt objects, however, it must be named after some figure in a creation mythology. We have decided to attempt to follow that ruling scheme.

All of the other planets are named for Greek or Roman gods, so an obvious suggestion is to attempt to find such a name for the new planet. Unfortunately, most of the Greek or Roman god names (particularly those associated with creation, which tend to be the major gods) were used back when the first asteroids were being discovered. If a name is already taken by an asteroid, the IAU would not allow that name to be used again. One such particularly apt name would have been Persephone. In Greek mythology Persephone is the (forcibly abducted) wife of Hades (Roman Pluto) who spends six months each year underground close to Hades. The new planet is on an orbit that could be described in similar terms; half of the time it is in the vicinity of Pluto and half of the time much further away. Sadly, the name Persephone was used in 1895 as a name for the 399th known asteroid. The perhaps more appropriate Roman version of the name, Proserpina, was used even earlier for the 26th known asteroid. The same story can be told for almost any other Greek or Roman god of any consequence. One exception to this name depletion is the Roman god Vulcan (Greek Haphaestus), the god of fire. Astronomers have long reserved that term, however, for a once hypothetical (now known to be nonexistent) planet closer to the sun than Mercury (god of fire, near the sun, good name). We would not want to use such a name to describe such a cold body as our new planet!

Luckily, the world is full of mythological and spiritual traditions. In the past we have named Kuiper belt objects after native American, Inuit, and [minor] Roman gods. Our new proposed name expands to different traditions, still. We hope it is accepted by the IAU and hope afterwards that it is embraced by all.

We have recently discussed the status of the object and of the name with members of the IAU who decide such things. As far as we can determine several activities are taking place:

A special committee of the International Astronomical Union (IAU)is trying to decide precisely what to classify this as.

Another committee of the IAU which vets names for asteroids and Kuiper belt objects is mulling over the name that we suggested upon discovery.
Yet another committee of the IAU which approves names for features on major planets and satellites has suggested that if the object is declared a major planet the naming falls strictly to them, and they have suggested that the name should continue the Greco-Roman tradition of the previous planets. We have a couple of interesting choices in mind in that case, though it is not clear that we as the discoverers will necessarily have a say in this case.

It appears that with the dead month of August rolling around no one will be making decision anytime soon, though the IAU has recently made an official pronouncement.

Is this object really a planet? Is Pluto a planet? What makes a planet?

Even after all of these years of debate on the subject of whether or not Pluto should be considered a planet, astronomers appear no closer to agreement. I wrote extensively about this at the time of the discovery of Sedna in March 2004. My thoughts have evolved since then, so it might be amusing to see what I said 1 1/2 years ago. I have been heavily influenced by writing a scientific review article this summer on the topic of "What is a planet?" with my colleague Gibor Basri at U.C. Berkeley who I thank for his insights. The main stumbling block in defining planets in our solar system is that, scientifically, it is quite clear that Pluto should certainly not be put in the same category as the other planets. Some astronomers have rather desperately attempted to concoct solutions which keep Pluto a planet, but none of these are at all satisfactory, as they also require calling dozens of other objects planets. While people are perhaps prepared to go from 9 to 10 planets when something previously unknown is discovered, it seems unlikely that many people would be happy if astronomers suddenly said "we just decided, in fact, that there are 23 planets, and we decided to let you know right now." There is no good scientific way to keep Pluto a planet without doing serious disservice to the remainder of the solar system.

Culturally, however, the idea that Pluto is a planet is enshrined in a million different ways, from plastic placemats depicting the solar system that include the nine planets, to official NASA web sites, to mnemonics that all school children learn to keep the nine planets straight, to U.S. postage stamps. Our culture has fully embraced the idea that Pluto is a planet and also fully embraced the idea that things like large asteroids and large Kuiper belt objects are not planets. "This cultural view is not scientifically consistent!" scream the astronomer. Scientists have not yet realized that the term planet no longer belongs to them. But, quite clearly, it does not. It is understandably hard for scientists to let go of a word that they think they use scientifically (and even in job titles like mine: "Professor of Planetary Astronomy"!) but they need to. The word "planet" has been around much longer than modern science.

From now on, everyone should ignore the distracting debates of the scientists, and planets in our solar system should be defined not by some attempt at forcing a scientific definition on a thousands-of-years-old cultural term, but by simply embracing culture. Pluto is a planet because culture says it is.

We are then left with two cultural choices. (1) Draw the line at Pluto and say there are no more planets; or (2) Draw the line at Pluto and say only things bigger are planets. Both would be culturally acceptable, but to me only the second makes sense. In addition, the second continues to allow the possibility that exploration will find a few more planets, which is a much more exciting prospect than that suggested by the first possibility. We don't think the number of planets found by the current generation of researchers will be large. Maybe one or two more. But we think that letting future generations still have a shot at planet-finding is nice.

Thus, we declare that the new object, with a size larger than Pluto, is indeed a planet. A cultural planet, a historical planet. I will not argue that it is a scientific planet, because there is no good scientific definition which fits our solar system and our culture, and I have decided to let culture win this one. We scientists can continue our debates, but I hope we are generally ignored.

What else is out there?
The last week of July 2005 was an exciting one for the outer solar system. In the course of two days the existence of three new objects was announced, and each object was brighter than all of the previously known objects in the Kuiper belt (with the exception of Pluto). The first object, 2003 EL61, was announced by a team from Spain. The second two, this planet and another new object named 2005 FY9, were announced from our survey the next day. With so many bright objects coming out at once it is hard to keep them all straight. Here is the quick score card:


2003 UB313

2003 EL61

2005 FY9

Brown, Trujillo, Rabinowitz
Ortiz et al.
Brown, Trujillo, Rabinowitz
bigger than Pluto!
~3/4 Pluto
~3/4 Pluto
4th brightest Kuiper belt object (KBO)
3rd brightest KBO
2nd brightest KBO
current distance
97 AU
52 AU
52 AU
orbital period
560 years
285 years
307 years
closest approach to Sun
38 AU
35 AU
39 AU
furthest from Sun
97 AU
52 AU
52 AU
tilt to the ecliptic
44 degrees
28 degrees
29 degrees
surface composition
when visib le
late summer, fall early winter
late winter, spring, early summer
late winter, spring, early summer

(note that though we consider Pluto and 2003 UB313 planets, they are also clearly members of the Kuiper belt, with Pluto the brightest member)

Here is where these extremely bright Kuiper belt objects are in the solar system these days:

Why the hasty announcement? What about the hacking? What is going on here?
Recent information has clarified much of what is described below. We no longer believe that the sequence of events described below is correct. Details to follow in a day or two. 8/10/2005

As has been widely reported in the press, the announcement of the new planet was made in a rather hasty manner because of fears that our discovery was going to be made public by someone who had hacked a web site and gained access to information about where the object is. The details are a little more complicated than this, the terminology can be debated ("hacked?" "sleuthed?" "stole?" "stumbled across?") and not all are 100% clear to me, but here is a reconstruction of the events that lead to the announcement as best I can discern them. Some aspects remain mysterious.

In mid-July short abstracts of scientific talks to be given at a meeting in September became available on the web (for example, here). We intended to talk about the object now known as 2003 EL61, which we had discovered around Christmas of 2004, and the abstracts were designed to whet the appetite of the scientists who were attending the meeting. In these abstracts we call the object a name that our software automatically assigned is, K40506A (the first Kuiper belt object we discovered in data from 2004/05/06, May 6th). Using this name was a very very bad idea on our part! Unbeknownst to us, some of the telescopes that we had been using to study this object keep open logs of who has been observing, where they have been observing, and what they have been observing. A two-second Google search of "K40506A" immediately reveals these observing logs. Ouch. Bad news for us. From the moment the abstracts became public anyone on the planet with a web connection and a little curiosity about this "K40506A" object could have found out where it was. Anyone on the planet with even a modest-sized telescope could then go find the object and claim a discovery as their own.

Interestingly, this is not what we then happened. The Spanish group headed by J.-L. Ortiz legitimately discovered the object on their own in data from 2 and 3 years ago. The fact that this discovery happened days after the data were potentially available on the web is, I believe, a coincidence. At the time, however, some in the community privately expressed their concerns to me that this coincidence was too good to be true and wanted to know if there was any possible way that anyone could have found out the location of our object. I insisted it was impossible. I was wrong. I myself went to Google late on the night after the Spanish announcement, typed K40506A into Google, and let out a gasp. Even though I don't believe the Spanish group did this, I realized anyone could have found our object with very little effort. To be very clear, from the first day I have very publicly stated that the official discovery credit goes to Ortiz et al. and no one else. We are pleased to be joined by the Spanish group in the very exciting quest for new objects in the outer solar system.

By Friday morning it occurred to me that once someone knew about the web site where the information on where the telescopes we had been using had been pointing it would take only a little more effort to carefully peruse this web site to see if we had been looking at anything else moving in the sky. At this point I contacted Brian Marsden at the International Astronomical Union's Minor Planet Center (MPC) by email, told him confidentially about the two objects that we had not yet announced (now known as 2003 UB313 and 2005 FY9), expressed my concerns that someone may be able to nefariously find our data and attempt to claim credit for discovering these objects, and sought his advice. His chilling response came less than an hour later: someone had already used a web service of the MPC to use past observations of an object to predict locations for tonight. The past observations were precisely the logs from the telescope we had used! The culprit and not even bothered to change the names that we used (K31021C for 2003 UB313 and K50331A for 2005 FY9). At this point we had no choice but to hastily pull together a press conference which was held at 4pm on the last Friday in July, perhaps the single best time to announce news that you want no one to hear.

All of this came about because of the perfect confluence of three factors: we used our actual code name in publicly available abstracts (dumb on our part), we assumed that no one would piece together information from the internet and figure things out (naive on our part), someone with astronomical knowledge was willing to go to some effort to obtain our data (unethical on their part). It's true that the information was available without breaking into any sites. It's also true that sometimes I don't lock the door to my house. I hope that people don't think it's therefore OK to come in and take my stuff.

We have been greatly saddened by this experience but have learned many lessons. It seems likely, however, that determined people with no ethics will continue to find ways to cause problems in all fields.

Why does it take so long to announce these discoveries?

Soon after the announcement of the discovery of the new planet the suggestion slowly made its way around the internet that we, the discoverers, were somehow violating long standing scientific standards by keeping the existence of the planet "secret" for so long. This suggestion seemed so bizarre to us that we paid no attention at first, but, as with many things on the internet, it has been repeated enough times even reasonable people are starting to believe it. We would like to quickly dispell this odd misconception.

One of the things that is so strange about this allegation is that it should also be made of every single scientific result that is published in a reputable scientific journal. In all such cases, scientists make discoveries, they verify their discoveries, they carefully document their discoveries, and they submit papers to scientific journals. What they don't do is make discoveries and immediately hold press conferences to announce them (one need only think back to the cold fusion days to remember how thoroughly the scientific community condemns such behavior). Good science is a careful and deliberate process. The time from discovery to announcement in a scientific paper can be a couple of years. For all of our past discoveries, we have described the objects in scientific papers before publicly announcing the objects' existence, and we have made that announcement in under nine months. These papers allow other astronomers to verify, confirm, and critique the analysis we have done. Sadly, because we were forced to announce 2003 UB313 prematurely, we have still yet to complete the scientific paper describing this object (it is now finally complete. see below). We find this situation scientifically embarrassing and apologize to our colleagues who are reduced to learning about this new object from reading reports in the press. We are hard at work on this scientific paper, but, as we said above, good science is a careful and deliberate process and we are not yet through with our analysis. Our intent in all cases is to go from discovery to announcement in under nine months. We think that is a pretty fast pace.

One could object to the above by noting that the existence of these objects is never in doubt, so why not just announce the existence immediately upon discovery and continue observing to learn more? This way other astronomers could also study the new object. There are two reasons we don't do this. First, we have dedicated a substantial part of our careers to this survey precisely so that we can discover and have the first crack at studying the large objects in the outer solar system. The discovery itself contains little of scientific interest. Almost all of the science that we are interested in doing comes from studying the object in detail after discovery. Announcing the existence of the objects and letting other astronomers get the first detailed observations of these objects would ruin the entire scientific point of spending so much effort on our survey. Some have argued that doing things this way "harms science" by not letting others make observations of the objects that we find. It is difficult to understand how a nine month delay in studying an object that no one would even know existed otherwise is in any way harmful to science!

Many other types of astronomical surveys are done for precisely the same reasons. Astronomers survey the skies looking for ever higher redshift galaxies. When they find them they study them and write a scientific paper. When the paper comes out other astronomers learn of the distant galaxy and they too study it. Other astronomers cull large databases such as the 2MASS infrared survey to find rare objects like brown dwarves. When they find them they study them and write a scientific paper. When the paper comes out other astronomers learn of the brown dwarves and they study them in perhaps different ways. Still other astronomers look around nearby stars for the elusive signs of directly detectable extrasolar planets. When they find one they study it and write a scientific paper..... You get the point. This is the way that the entire field of astronomy -- and probably all of science -- works. It's a very effective system; people who put in the tremendous effort to find these rare objects are rewarded with getting to be the first to study them scientifically. Astronomers who are unwilling or unable to put in the effort to search for the objects still get to study them after a small delay.

There is a second reason that we don't announce objects immediately, and that is because we feel a responsibility not just to our scientific colleagues but to the public. We know that these large objects that keep being found are likely to be the result of intensive interest by the public, and we would like to have the story as complete as possible before making an announcement. Consider, for example, the instantaneous Ortiz et al. announcement of the existence of 2003 EL61. Headlines in places like the BBC web site breathlessly exclaimed "new object may be twice the size of Pluto." But even at the time we knew that 2003 EL61 had a satellite and was only 30% the mass of Pluto. We quickly got the truth out, but just barely. Sadly, other interesting aspects of 2003 EL61 also got lost in the shuffle. No one got to hear that it rotates every 4 hours, faster than anything else known in the Kuiper belt. Or how that fast rotation causes it to be shaped like a cigar. Or how we use the existence of the satellite to calculate the mass. All of these are interesting things that would have let the public learn a bit more about the mysteries of physics and of the solar system. In the press you get one chance to tell the story. In the case of the instantaneous announcement of 2003 EL61 the story was simply "there is a big object out there." We are saddened by the lost opportunity to tell a richer scientific story and to have the public listen for just one day to a tale that included a bit of astronomy, a bit of physics, and a bit of detective story.

Given that we do precisely what other astronomers do and that we are actually very prompt about making announcements, where did the crazy ideas that we should be announcing objects instantly come from? Interestingly, there is one area of astronomy in which instantaneous announcement is both expected and beneficial to all. In the study of rare, quickly changing objects, such as supernovae, gamma ray bursts, comets, and near earth asteroids, astronomers quickly disseminate their results so that as many people as possible can study the phenomenon before it disappears or changes completely. No one discovers a comet and keeps it to himself to study, because by the time the study was done the comet would be gone and no one else could study it ever again. The people initially suggesting that we were wrong to not announce our objects instantly are, for the most part, a small group of amateur astronomers who are familiar with comet and near earth asteroid observation protocols. We can only assume that this familiarity led them to their misconceptions. Kuiper belt objects are not quickly changing phenomena. Astronomers will be intensively studying 2003 UB313 for a long time to come.

We hope to discover a few more large objects in the outer solar system. When we do, we will do everything we can to learn as much as possible about them before we make their existence public, and we will try to make the announcement as complete and scientifically and publicly interesting as possible. We will take the chance -- as all scientists do -- that by taking the time to do the scientific job correctly someone else may beat us to the announcement, and if they do we will congratulate them heartily.

The scientific paper describing the discovery is finally done!
As described in detail elsewhere, we were forced to announce the existence of 2003 UB313 before we had finished a scientific paper describing the discovery. While announcing discoveries via press releases with no scientific paper is generally frowned upon by scientists (including us) our colleagues have been understanding of the unusual circumstances under which this happened. The scientific paper describing the discovery has just been submitted to the Astrophysical Journal. If you are curious what one of these papers looks like you can read the entire text. Now that the paper has been submitted to the journal, the journal will send it out for peer-review, where another scientists will carefully and critically read what we have read and help decide if the paper meets accepted scientific standards. In almost all cases, the reviewer will suggest at least some changes to the manuscript before the paper is finally accepted. This process helps ensure that published scientific papers are as accurate and complete as possible.

Back to Ice World Introduction or the Syllabus.

| Home | Course Information | Assignments | Teacher Bio | Course Units | Syllabus | Links