A thoroughly sporadic column from astronomer Mike Brown on space and science, planets and dwarf planets, the sun, the moon, the stars, and the joys and frustrations of search, discovery, and life. With a family in tow. Or towing. Or perhaps in mutual orbit.



We'll always have Regulus

I find Paris disorienting.
First, I missed an entire nighttime. When my wife and I arrived at the airport to embark on our vacation it was a southern California late afternoon. When we landed – first in Zurich – it was a Swiss early afternoon. Somehow I had missed an entire fast-forward cycle of the sun setting, the stars rising, and the sun rising again, all in the space of about 4 hours. When I first closed my window shade and then closed my eyes on the airplane – somewhere over Salt Lake City, I think – I made a mental note to be sure to try to open up and see the sunrise – over Greenland, I guessed. But even for the fitful sleep of a bumpy airline seat the sunrise came too quickly. When the thought to open my eyes and look out the window finally solidified sufficiently inside my head we were already over Ireland. I slid the window shade open a tiny crack to take a peak and the entire darkened airplane cabin was blasted with late morning glare. My wife, still attempting to sleep in the seat next to me, added her own glare to that of the sun and I quickly closed the shade. By the time we landed in Zurich and then finally continued on to Paris the sun was already on its way down again, but, still, I feel like a lost nighttime in there somewhere. Nights are precious things, and one should not lose them lightly.
If losing a nighttime were not disorienting enough, I believe that the streets of Paris are uniquely designed to make me lose my sense of direction. I pride myself, most of the time, with having a finely tuned sense of direction. I tend to be able to get from point A to point B by dead reckoning, no matter how many twists and turns and detours are along the way. So on the streets of Paris my general navigational strategy is to take a look at a map to see where we are and where we would like to be, and then I head off in what seems to be the correct general direction knowing that I will get to where I’m going. But the streets of Paris are tough. It’s not just that they aren’t oriented along a north/south axis. It’s not even that they aren’t oriented along any single axis. And it is not even that the streets sometimes curve. It’s that all three of these occur in small quantities. A street that I am on starts out general north-northwest, which, in my head, I probably think of as “northish” and then the street slowly, imperceptible turns west or even perhaps a little south. I then take a left turn onto a street which I think of as going westish when, in fact, it is more like the north-northwest direction I was originally headed. Do that a few times and there is no telling which way you are really going.
The first night we arrived, jetlagged and awake at midnight, I thought it would be fun to walk down to the Seine to see Notre Dame lit up at night. Point A: our hotel. Point B: Isle de la Cite. Direction: north-nothwest. After about 45 minutes of walking in the bitter bitter cold (ok, I live in southern California, so the fact that it was only a few degrees above freezing qualifies as freezing for me) we stumbled out of some small twisty city streets directly into the Pantheon, which was indeed spectacular all lit up after midnight. I’d never been to the Pantheon before and didn’t quite know where we were. I finally got out the map. We were a block from our hotel. Point A to Point A in just 45 near-freezing minutes. My wife gave me a similar glare to the one from earlier that morning.
Paris is a city to which my wife and I have both been a few times, but which we do not know well. We’re staying in a part of town which I have never visited. Our college French is rusty. An after flying for 12 hours and missing a full sunset and sunrise and finding myself unable to make it to one of the most obvious landmarks in town and struggling to remember the French phrase for, say, “Excuse me, madame, but do you know why I seem to keep walking in circles?” I feel very very far away from home in Pasadena. Looking at the globe you can see just how far it is, as I kept explaining to Lilah, our 3 ½ year old, who wanted to understand exactly where we were going to be (a place she calls “Parisfrance”) while she stayed home with her grandparents. “Parisfrance is really really far away Daddy. If I were on the airplane I would have to fall asleep.” A wise girl, I think.
But then, still trying to straighten out my post-midnight rambling route, we hit a slight opening to the sky and the clouds clear a bit and there, a bit low in the sky in about the direction we’re heading is a bright star and a little backwards question mark of fainter stars. The constellation is unmistakably Leo. The star is Regulus.
“Let’s turn around” I say to my wife. “We’ll be going in exactly the right direction.”
It’s the same sky. Pasadenacalifornia or Parisfrance look out into the same night and lie underneath the same stars. Fly 12 hours, miss a sunset and sunrise, forget the language if you want, but Regulus will still be there. I used Regulus once to get myself unlost while driving in New Jersey trying to figure out the direction of the shore (my friend in the car with me couldn’t figure out why I pulled off the road, stuck my head out the door, and looked up, before making a U-turn, but that was the best you could do pre-GPS navigation) and used it to find Notre Dame.
I’ll show it to Lilah when I get home. “Hey Lilah, that star is called Reguls and I could see it from Parisfrance” and she might find it wonderful and mysterious and amazing that you can see the same thing from such different places. Or she might ignore me and say “Daddy Daddy I’m going to draw a picture of a ghost for you” or who knows what else. But I will remember that it is wonderful mysterious and amazing that that’s the same star that showed me which direction to turn on a tiny street after midnight in a big city halfway across the world.

[next week: a name for Orcus's moon. I haven't had a chance to read any of the suggestions yet (being on vacation in Paris), but I see that there will be many many to chose from. Stay tuned.]

S/1 90482 (2005) needs your help

“S/1 90482 (2005)” is really not much a name as a license plate number. As does a license plate number, it tells you pretty much everything you need to know to identify the object in question. “S” is for satellite. “/1” means it is the first discovered. The “2005” at the end tells the date of discover, and the “90482” tells whose satellite it is, but only by yet another number. This number refers to the 90482nd minor planet (in the old terminology; no one quite knows what the new terminology is, but the numbers keep coming) to be officially recorded. That object is more commonly referred to as the large Kuiper belt object Orcus. We don’t ever call the moon of Orcus by its official name of S/1 90482 (2005). Instead, around here, it is referred to mostly as “the moon of Orcus.”

It’s time to change that.

Not all of the Kuiper belt objects known and number have names, and, as I have written here earlier, I think most don’ t need them. It is OK to consign them to semi-anonymous license plate numbers if they are never really going to be thought about as more than one of the crowd. But a few special objects get studied and talked about and written about enough that need not so much just names, but also personalities. Orcus was one of those objects. Its personality was quite apparent from the beginning.

We discovered Orcus in early 2004. At the time it was the 4th largest known Kuiper belt object, though by now it has dropped to something like 8th. The most interesting thing about Orcus to me was that it appeared to be the anti-Pluto.

Pluto has what was originally thought to be a peculiar orbit. It circles the sun precisely two times for every three times that Neptune goes around the sun. Though it took astronomers a long time to realize it, this peculiarity is not a coincidence. Neptune’s gravity so dominates the region of space where Pluto is that Neptune has herded Pluto into this very special orbit. Pluto is not the only one that Neptune is pushing around. We now know of hundreds of similar objects in the Kuiper belt, including, now, Orcus.

Pluto’s orbit has a few other interesting features to it. It is so elongated that, for a brief time during its revolution about the sun, it actually comes close to the sun than does Neptune. So does Orcus. When Pluto comes close to the sun, though, it is never actually close to Neptune, partially because at that point in its orbit it is high above the disk of the planets, hitting the most extreme spot of its tilted orbit. Just like Orcus.

In fact, if you look at the orbits of Pluto and Orcus (and I encourage you to do it if you never have; check out the extremely cool orbit plotter at JPL but you'll have to zoom out to find Orcus), you will see that they are nearly identical except for 2 things. Their elongated orbits point in nearly opposite directions, and, right now, Pluto is nearly as close as it ever comes to the sun while Orcus is nearly as far away as it ever comes. In fact, because Pluto and Orcus are forced by Neptune to have precisely the same orbital period, they will always stay in opposite phases of their orbits.

Orcus is the anti-Pluto.

Several years ago, when searching for a name for what was then known only as 2004 DW, we decided to concentrate on the anti-Pluto aspect of the object’s personality, and we came up with Orcus. In the version of the Orcus myth that I like to tell, Orcus was, essentially, the early Etruscan grim reaper, collecting the dead and bringing them to the underworld where another god – Pluto – ruled. As the Etruscan mythology was incorporated into Roman mythology and blended with Greek mythology, Orcus lost his separate identity and Pluto became the master of all of the functions of the dead. Orcus became in some ways simply an alternate name for Pluto, but it also remained a slightly more evil and punishing incarnation of Pluto. In that incarnation, the Latin word Orcus was the origin of words such as ogre and orc.

In my new mythological/astronomical view, Pluto the Kuiper belt object is now named after that earlier version of Pluto, before the Romans came along and swept everything together. And Orcus is his counterpart, destined to eventually be pushed aside by the rising Pluto. Orcus seemed a very appropriate name for this new object in the Kuiper belt.


About a year later, while looking carefully at Orcus with the Hubble Space Telescope, we realized that it had a moon. In the past year we have been studying the moon of Orcus intensely and are in the final stages of writing a scientific paper on all of the interesting things about this moon. Which means it is time to stop calling it “this moon” and give it a proper name. But what?

Here’s where you come in. Send me suggestions! I’ll submit the best suggestion to the International Astronomical Union on Sunday, April 5th (about 2 weeks from now) with your name as part of the official citation (if you want it to be).

If you make a suggestion I would like to know not just what the suggestion is, but why you think its appropriate. As you can tell by now, this is the part that matters to me!

To help you out, let me tell you some of the other interesting things about the satellite. It has about a ten day orbit around Orcus, in a tight precise circle. We suspect – though can’t yet prove – that Orcus and its satellite have their same faces locked towards each other constantly, like an orbiting dumbbell. Only one other Kuiper belt object and satellite are known to do this. Who? Pluto and Charon, of course.

The origin of the satellite of Orcus is confusing. Pluto and Charon are thought to have formed in a giant collision. Haumea clearly had a shattering blow to disperse moons and other family members. But small Kuiper belt objects are thought to acquired moons by simple capture.

Orcus is right in the middle. Was the satellite from a collision or a capture? We had hoped to answer this question by observations from the Hubble Space Telescope. If the satellite had looked just like other known collisional satellite, we would have been pretty convinced. It doesn’t. Unfortunately that tells us less. We can’t rule out either. We have some ideas of new Hubble Space Telescope observations to try to tell the difference. For now, though, we’re just confused.

While the scientific paper will have more details and calculations, that will be the gist of it, and those properties are all you get to know to try to discern the personality of the moon of Orcus and to try to pull out the right name.

You can send suggestions as comments to these pages (www.mikebrowns planets.com in case you are reading this elsewhere) or simply email me (mbrown@caltech.edu ), but please put “Orcus” in the subject line so I don’t mistake you for a potentially business partner from Nigeria.


Good luck. S/1 90482 (2005) is counting on you.

To the moon

My father was a rocket scientist. Well, OK, not precisely. More specifically he was a rocket engineer. Or, more precisely still, he was an engineer who worked on the computers that went into space and navigated the rockets. He worked on the Saturn V that lifted Apollo astronauts toward the moon, he worked on the Lunar Module, which touched down on the moon, he worked on the Lunar Rover, which drove astronauts around on the moon. All of this before he was 30 years old.

I never remember him talking about it at all, talking about what it was like to send men to the moon, to be involved in such a tremendous adventure, but, ten years ago, in the little farming town on the edge of the Mississippi River where he grew up, I had a conversation with one of his friends from those days, and he told me that they all felt like they had lived in a magical time. After the Apollo missions ended, they all later worked on the Space Station and more mundane things like the ticket-taker on the BART trains that I used to take when I was a graduate student living on the San Francisco Bay. But nothing in their lives was ever quite like a being a bunch of thirty-year-old kids living in northern Alabama having the blind optimism to think that if there was a rocket being built they knew enough to put the computers together to make those rockets bring people to the moon. And back. And then actually doing it.

I wish I could ask him about it, but that opportunity is a decade gone.

Being the mid nineteen seventies, he had a marriage and he had three children – me, my older brother Andy, my younger sister Cammy – all before he turned 30, and we all lived in what now seems to me like a huge house in northern Alabama. Being the mid nineteen seventies, the marriage didn’t last. He moved to an apartment across town, then to Maryland, then to North Carolina, then to Houston, and finally, for his last few weeks, back to North Carolina to stay in the house of my sister.

In those last few weeks my brother and I were there at my sister’s house, too. I was in the middle of my third year of being a professor at Caltech and I was still trying to get on my feet. But, that quarter, I simply canceled my class midway through and gave everyone in attendance an “A.” Oddly, I had no complaints. I then flew across the country to meet my father and my sister and soon my brother and we all stayed in North Carolina for a while.

It was too late then to say much. He was mostly groggy from the pain medication. But we talked some about what was happening in all of our lives. Though he never would say such a thing directly, I think he was proud that I done well enough at school to land a job being a professor at Caltech. I remember complaining about some of the more mundane aspects of the job to him and having him softly glare back and whisper: “do you know how lucky you are?”

I told him about a new project I was starting that I was quite excited about. We had just started using an old telescope at Palomar Observatory to make repeated wide-field observations of the night sky in search of particularly large objects in the outer solar system. I told him that I was certain there would be things larger than Pluto out there to see and that I really hoped to be the one to find them. He always liked long-term plans and was happy to see that I finally seemed to have one. “But what if there isn’t anything out there?” he asked, in his always not-quite-so-encouraging way. There will be, I said. I’m sure there will be.

We talked about the long term relationship I was in that, though I didn’t know it at the time, was within a month of finally falling apart. I told him why the relationship was hard and not going so well. I remember perhaps the only words of relationship advice he ever gave me: “There shouldn’t be any fighting. Find someone you don’t fight with.” Though the words resonated with me, my father’s accumulated lifetime credibility in this realm was not high. So I filed the advice away.

He died a few days later. It was ten years ago today.

I’ve missed not having a father for the past decade. I feel we were still, that late in both of our lives, getting to know and understand each other, something we had never had much of an opportunity to do when I was younger.

But, today, I am thinking of the things that I wish I had the opportunity to show him over the past decade. I don’t have much in the way of spiritual beliefs about any afterlife, but, if there is one, and the deceased person can pick his form of communication with the corporeal world, I am pretty sure that my father would pick the web. When he first got cancer nearly 20 years ago he immediately took to the then-new internet as a means of educating himself and everyone else about everything to do with the cancer, the treatments, the options. It’s the sort of thing that everyone does routinely these days, but, back then, it was still quite novel. So if he’s out there anywhere, I like to think of him hooked in through some vast astral server. So this is for him, vial HTML, which he first introduced me to:
Dad –
A lot has happened in the past decade that I think you’d have been proud to have heard about, but there are three that I really wish I could share with you.

Remember that project I told you about ten years ago? The one that started looking over vast swaths of sky for things that moved? The one where I thought I would find another planet? Well, it took a few years before it began paying off, but it has been a pretty spectacular ride. There were indeed things out there to be found. One – so far – was even bigger than Pluto. I wouldn’t have guessed at the time, but all of it caused a big shakeout in the solar system leading to the new decision to recognize only 8 planets. That’s a pretty big change from your lifetime, where Pluto was a planet when you were born and Pluto was a planet when you died. I think you would have enjoyed watching the changes happen. And I sort of suspect that, though you would never actually say it directly to me, you would be somewhat proud of me. I’m sorry you weren’t around to see it.

Some other big news of the past decade: you were right about relationships and fighting, I think. Who would have guessed that? It took me another four years after that conversation, but I did find that person you were trying to guide me towards. I got married to Diane six years ago. I know that you were perhaps always convinced that no one was ever good enough for one of your kids, but, I have to admit, I think you would be charmed. I look at the picture that was taken on our wedding day sometimes, the one that has Diane and me and my brother and his wife and my sister and her husband and their two kids and my mother and my step-father and I wish that you were in the picture too. It would have been a bit awkward, these extended family things always were, but the awkwardness would have been better than the empty spot that I now see every time I see that picture.

There’s one more thing I wish I could show you. Her name is Lilah, and she is a 3 ½ year old bundle of silliness, stubbornness, curiousness, sweetness, and talkativeness. It is part of the mythology from my childhood that you were not particularly pleased about having that third child, but when it turned out to be a baby girl you pretty quickly got over your misgivings. I think you would like Lilah, and I think it would be pretty hard for you to hide. She asks about you sometimes. She asked about you this morning, even. “But Daddy, who was your daddy?” and I tell her about you. “Why did he die?” she asks. I explain about being sick, about having cancer. She understands a little, but, clearly, only a little. “Do you get another daddy when yours dies?” No Lilah. You never do. You never, ever, do.

What Lilah doesn’t yet know is that you don’t want another daddy when yours dies. You just want yours back. And when you realize that that is never going to happen, you at least want a chance to tell him a few things. And you hope that he has some chance of listening in, at least every ten years or so.

Snow White needs a bailout

I was reading the business section of the Sunday New York Times this morning – something I do only when it is still a little chilly outside and I am not quite motivated enough to get on my bike and head up the nearest mountain – and I got engrossed in an article about how ten or so billion of dollar had been given to this or that bank and how much of it had evaporated. The main thing I thought was “Ten or so billion dollars. That’s really not that much these days.”

It’s true. A year ago the loss of that much money would be front page of every newspaper, instead of buried inside of an analysis in the business section. We were all getting used to such numbers that only hundreds of billions – or perhaps trillions – matter much anymore.

It reminds me a lot of the Kuiper belt.

Almost seven years ago we discovered our first truly large object in the Kuiper belt. It was given the license plate number of 2002 LM60, but we quickly named it Quaoar, after the creation force of the Tongva Native American tribe indigenous to the Los Angeles basin, in homage to the fact that the discovery was made by us right here in the Los Angeles basin. Quaoar made the front page of most major newspapers (except, amusingly, the Los Angeles Times).

At the time of the announcement of the discovery, the most important thing that we knew about Quaoar was that it was about half the size of Pluto. It was thus likely bigger than anything that had been found in the solar system in the past 72 years. The main part of the story that newspapers honed in on was, of course, whether or not Pluto should actually be called a planet. My very favorite quote, published in the Birmingham, Alabama newpaper, quotes me saying “Quaoar is a big icy nail in the coffin of Pluto as a planet.” Pretty good quip, I thought.

The hunt continued.

The next year we announced the discovery of Sedna, both larger than Quaoar and on a distant elongated orbit that made it more distant than anything else that we had ever found. Explaining that odd orbit has been a task I have been trying to continue to this day. I still don’t know the answer, but the mystery made the front cover of Discover magazine.


The hunt continued.

A year later we hit the jackpot, with the discoveries of Haumea, Eris, and Makemake. With Eris being larger than Pluto and eventually providing the silver bullet into the heart of Pluto’s planethood, it received a lot of attention.


The hunt continued.


After some time we started all over again, looking specifically for really super distant things like Sedna. We found a lot of things, but only one thing really far away. It wasn’t as far as Sedna, or even as far as Eris, but it was indeed the third most distant thing we had ever seen.


By now we understood the distant Kuiper belt to know that, basically, we should never see it. The only reason we ever see things is when they are brighter – or more reflective – than they are supposed to be. The only reason that things are more reflective than they are supposed to be is that they are big. The only thing that made sense is that this new thing we had found was big and reflective.


We nicknamed it Snow White.


The survey that found Snow White was specifically looking for quite distant things like Sedna; things that would help us better understand the beginning of the solar system. Snow White, we finally learned, was not like Sedna at all. It was just a normal Kuiper belt object found slightly far away. Bigger than most, but otherwise, as far as we knew, unremarkable.


What to do?


Our normal policy is to delay the announcement of particularly interesting Kuiper belt objects until we have prepared a full scientific paper on them. Snow white perhaps deserved the same treatment. It is big; big is inherently interesting. But… we had nothing interesting to say about this one. It has a typical Kuiper belt object orbit. Its reflectance spectrum shows nothing particularly unusual.


It’s just a big Kuiper belt object. Perhaps even the 5th largest one known. It probably fits between Sedna and Quaoar in size. A few years ago it would have been front page news. Now? Yawn. Nothing.
A few people have written me asking why the press has been so unkind as to ignore Snow White. But don’t blame the press. Just blame me. We didn’t even write a press release to warn the press that there was anything interesting to write about. Because, in the end, I couldn’t think of anything interesting to write about.
It’s just a big Kuiper belt object. I don’t think that it individually tells us anything particularly new about the outer solar system. Quaoar was a good signal that Pluto’s demise would come soon; Sedna was a sign of an entirely unknown distant population; Haumea and Makemake and Eris were each scientifically rich in the things they taught us about what it is like to be a tiny icy body.


Snow white? Well, it’s just a big Kuiper belt object.


Someday we’ll learn more. Perhaps it will have a moon. Perhaps our quick look at surface composition overlooked something particularly interesting. If so, we’ll be ready with a bail out: prepare a full scientific paper, maybe even tell the press this time and use the opportunity to educate the public, once again, about what is fun and interesting out there at the edge of the solar system.

Lilah Brown's Planets, Part II (or, Season II preview)

Friday night my wife and my 3 ½ year old daughter Lilah picked me up at work to go have some dinner. When I opened the car door, Lilah, who it appears was about to explode from waiting to tell me something, blurted out “Daddy, daddy, daddy LOOK!” and pointed off to the west with an excited look in her eye. I followed her finger to a spot above the horizon where a thin sliver moon was shining down with Venus just a finger width to its right. “It’s Venus and the moon,” she breathlessly exclaimed, “and the moon is little but it is pretending to be full,” her words to describe the ghostly outline of the full moon seen in the background of the bright glint of the crescent moon.
“Daddy daddy daddy do you remember when we saw Venus and the moon and Jupiter, too?”
I do indeed remember that. That moment was the December crescent moon, three full lunations ago. It was also the moment that I like to think of as the final episode of the first season of Mike Brown’s Planets. Like any self-respecting TV production, I’ve been taking a summer hiatus. It’s just that my hiatus occurred during southern summer rather than northern summer.
I’m not sure what TV production crews do during a hiatus but we’ve been pretty busy here at Mike Brown’s Planets, doing a bit of science. You’ll get to hear all about it in upcoming installments. Some of the highlights upcoming include:
  • Name a satellite of a Kuiper belt object! I’ll tell you about the Kuiper belt object and its satellite and then I’ll take suggestions of what to name the satellite (and why). The best suggestion will get forwarded to the IAU as the official recommendation.
  • Life, death, and the Kuiper belt.
  • More and more and more moon shadows. Last season readers here were the first to hear about the ongoing shadow crossing of Haumea by Namaka (and why they are both important and cool). Much much more is to come (and you can read more about it in an ongoing technical blog intended more for research astronomers, but, nonetheless, occasionally entertaining)
  • My father, rocket scientist, RIP
  • A (slightly belated) look forward at discoveries that might be made in 2009 and a look back at the 2008 predictions to see how many, if any, came true.
  • Why Pluto is still not a planet and should remain that way.
  • Things in the sky that make me smile.
Stay tuned for Season II!