Monday, June 30, 2008

Professor Astronomy and the Supercollider of Doom


Image Credit: CERN

The "Doomsday Supercollider" sounds like some bad B-movie plot, or something that Indiana Jones or James Bond might be out to stop. But, in fact, it is a horrible misnomer for one of the most exciting physics facilities to come along in decades, the Large Hadron Collider, or LHC (picture above).

For years, news stories have been circulating (including one on CNN today!) that the LHC could produce a miniature black hole that will quickly swallow the Earth, or a piece of strange matter that will convert the entire Earth to strange matter, killing us all.

This is balderdash. Bunk. Crap. The people proposing this are misinformed, wrong, and wasting energy protesting a threat that doesn't exist.

First, what is the LHC? Simply, it is a new and more powerful particle accelerator ("atom smasher") nearing operations in Switzerland. The LHC will run experiments to try and confirm several theoretical subatomic particles, perhaps including dark matter particles , that have been theorized but never proven. Finding some of these particles (like the Higgs boson) will be final proof that our current ideas about subatomic particles and quantum physics are correct. Finding new particles, like dark matter, would go a long way toward understanding the stuff that makes up 25% of our Universe.

Some scientists have theorized that the experiments might be capable of making miniature black holes (many times smaller than the size of our smallest subatomic particles). Other people started worrying about this, because they fear that such a black hole would quickly swallow the entire Earth. This is wrong. A black hole can only swallow stuff within its reach, and the reach of a black hole is only a few times its diameter. Any black holes that are made would be so small that they could fit inside the nucleus of an atom and not swallow anything. Further, if Stephen Hawking's ideas on black holes are correct, any black hole would quickly evaporate in a shower of subatomic particles. And if Hawking is wrong, the black hole will fly off of the Earth at almost the speed of light. We'd never see it again.

Other scientists have hypothesized that the experiments might make "strange matter" (a form of matter that is rarely seen), and a few others have taken this much further and said that these "strangelets" might be able to convert the entire Earth instantly to strange matter, which would destroy the entire planet. I know little about the properties of strange matter, but I am not worried.

Why don't I worry?

First and foremost, the Earth has naturally been conducting the same particle experiments for 4.5 billion years. High-energy particles called cosmic rays routinely hit Earth's atmospheres at energies much higher than the LHC, and the Earth hasn't been swallowed by black holes or converted to strange matter yet. If either of these fears were remotely founded, the Earth would have been destroyed eons ago.

Second, while there may be a misanthropic scientist or two here and there who doesn't care much for other people, the thousands of scientists involved in the LHC are well-adjusted human beings. They don't want to destroy the planet, and they would not engage in any activity that had the slightest chance of doing so. After all, what good is running an experiment if you can't be around to study the results, and if it destroys your home, all of your family and friends, and you as well?

There are many true dangers to Earth and society. Global warming, war, hunger, and poverty are some of the biggest threats facing us all. We should worry about those, not the non-existent threats being espoused by a few mis-informed people.

The Large Hadron Collider is not a threat to the planet. If you hear people spreading rumors about it, let them know the facts. Ignorance is not bliss in this case, but leads to needless worry and energy spent on tilting at windmills instead of at true enemies.

On the road again...

Yesterday evening I got home from the teacher continuing education workshop at McDonald Observatory, and today I am at the airport, ready to fly to Hawaii to use the Keck telescopes. It will be a fun trip, but I'll be ready to come home.

Saturday, June 28, 2008

The weather finally broke

After two very cloudy and stormy nights, we finally had some nice weather for our workshop participants last night. Above is a picture of Saturn I took with my point-and-click camera at the start of the night.

I felt bad that we closed down a little early. It looked like some thunderstorms were coming in, and with 20 people standing outside on top of a mountain, I just didn't feel comfortable. But the storms skirted us, and the sky became crystal clear again. But by that time, our teachers had left.

Still, they got three hours of observing, and the weather is looking promising (though still quite iffy) for tonight.

Day 2 of our science teacher workshop

Participant Jesse Whitaker explores the properties of light.

Here with another special report from the McDonald Observatory "Age of the Milky Way" teacher continuing education workshop is participant Dan Maloney:

Day 2 Summary – Yesterday was another very informative day for the teacher workshop. The group was led by our mentor teacher Jody through several classroom activities. The first was on the life cycle of different stars, and the second was on light spectrum analysis. For the life cycle of stars students blow up different colored balloons to learn what they eventually “explode” into. Students will definitely be surprised by how the death of a star occurs. For the light spectrum activity students examine how different colors of the spectrum change under various conditions. Both activities foster inquiry based learning and are suitable for a wide range of science and astronomy classrooms.

For the second night we have been not able to get in any observing time due to the weather but we are very optimistic that the weather will clear before the end of the workshop. Despite the weather we have been busy learning about white dwarfs and the group has started our preliminary analysis on white dwarfs using the imaging software program called ImageJ.

The group was also treated to a tour of the 82 inch Otto Struve telescope, which was built in 1938. The telescope is engineering masterpiece that is fully functional and serves astronomer in a wide variety of astronomical research. Today we will be touring the Hobby-Eberly telescope. I can’t wait.

Thursday, June 26, 2008

Special Guest Blogger

As I mentioned yesterday, I'm helping to run a science teacher continuing education workshop at McDonald Observatory this week. I've invited our participants to be guest authors. Today's guest is Daniel Maloney, a teacher in Troy, NY.

Day 1 Summary – Our first day at the McDonald Observatory was very exciting. Our day began with staff and participant introductions. We immediately went to work with Dr. Williams discussing how we determine the age of our galaxy. He went on to discuss characteristics of the Milky Way such as its disk size, the halo, bulge, and bar. He also talked about how the ages of globular clusters can be obtained from White Dwarfs. White Dwarfs are dense stars with a radius the equivalent to that of the Earth but with a mass the size of the Sun. White Dwarfs are at the end stage of their stellar evolution, and thus no nuclear fusion is taking place in its core. However, White Dwarfs still emit visible light and therefore are clues that point to the origins of the universe, and that is our mission!

We then were introduced to Dr. Jim Liebert of the University of Arizona via teleconference, who spoke about stellar evolution, and introduced the group to Hertzsprung Russell (HR) diagrams. This provided us with further background on what we will be researching over the next few days.

As a group we will be choosing patches of sky, and using the telescopes of the McDonald Observatory to locate and analyze White Dwarfs that exist in the Milky Way. We were unable to spend time observing last night due to thunder storms and cloud cover, but the weather looks great for today and we’re optimistic that we will be spending significant time observing and searching for White Dwarfs. Everybody is friendly, the food and accommodations are first rate, and I learned an awful lot in just one day.

Wednesday, June 25, 2008

The Age of the Milky Way Teacher Workshop

Yesterday I survived my 8-hour drive from Austin to McDonald Observatory for the 2008 version of our teacher continuing education workshop. It was a gorgeous drive, with thunderstorms building in the distance, lots of sunshine, and very empty roads.

Today our teachers arrived, 14 high school science teachers who braved $4/gallon gas to drive and learn a little astronomy. We got them into hard-core research right away; the picture above shows one group working on cutting and pasting. (We made sure to give them safety scissors for cutting.)

We're hoping for clear weather tonight, but the weather forecast is not very favorable.

Tuesday, June 24, 2008

back home and then off again

After a much-needed vacation last week, I arrived home yesterday afternoon just in time to do some laundry and prepare for our annual teacher workshop at McDonald Observatory. In the next several days, I'll blog their experiences (and maybe even get some guest bloggers). For now, I need to hop in the car and drive across Texas.

New Comments Policy

In the last week, several posts (mostly old ones) had spam comments posted. I think I've deleted most of these, but let me know if I've missed one.

Further, maybe it's now a good time to put into writing my (previously unspoken) comments policy. I haven't had any trouble beyond the occasional spam, but for posterity:

  1. I retain the right to change the method of posting comments, to change this comments policy, or to disable comments altogether, without any notice.
  2. I receive email notification of every comment, so it's no use trying to hide comments on old posts.
  3. Please don't make any personal attacks on people. If a flame war breaks out, I'll kill the comments pronto. Unwarranted personal attacks will be deleted.
  4. Please keep comments relevant to the discussion at hand. Comments that I feel are way off-topic may be deleted.
  5. Comments containing foul language will be deleted. This is a family-friendly site.
  6. Comments containing advertising for commercial products are not allowed. Any such comments will be deleted.
  7. Advertisements for events (such as meetings, TV shows, movies, etc.) that may be of general interest may be posted, but I reserve the right to review and delete any such comments without notice.
  8. Comments that are libelous or slanderous are illegal and will be deleted upon detection, though a copy may be retained for law enforcement.
  9. If you see a comment that you feel is inappropriate, please let me know. I will respond as I see fit, which may include deleting said comment, allowing a rebuttal, or no action at all.

I am a strong believer in freedom of speech, and I am generally pretty tolerant. In fact, I encourage discussion and commenting. And, as I said, there haven't been too many problems yet. But I do intend to keep a tight lid on things. If you want to argue with me or with someone else, there are other forums for such things. Thanks for your understanding.

Monday, June 16, 2008

vacation!

I'll be on vacation for the rest of the week, so you'll have to manage without me for a few days. See you next week!

Next stop, Hubble!

After years of uncertainty, cancellations, reinstatements, and delays, the shuttle mission to repair the Hubble Telescope for the last time is finally next on the list.

On Saturday, the space shuttle Discovery landed after another successful mission to the International Space Station. It will be another four months until the next space shuttle launch, when Atlantis is sent on her last (scheduled) mission, to repair the Hubble!

Hubble is showing signs of age right now. It's a healthy telescope, and still capable of outstanding science, but its health is on the decline. Its rechargeable batteries are wearing out, two of its cameras are broken, and its running on only two gyroscopes (three are preferred, but it is saving one in case one of the working gyroscopes fails). Atlantis will return Hubble to almost-new condition (think factory-refurbished), if all goes well.

The plans are ambitious. First, one old camera will be removed and replaced with a new one. When the new camera goes in, one other instrument, the "glasses" that the first Hubble repair mission put to correct for Hubble's mis-shapen mirror, will also be taken out. All the remaining instruments have their own internal glasses. This will allow another brand new science instrument to be put on. Hubble will get new batteries, new gyroscopes, and one malfunctioning navigation camera will be replaced. And, if all of that goes well, the two broken cameras will also be fixed.

It is quite possible that not all of the repairs will be done. The two broken cameras were never meant to be fixed in space, so we don't know if the repairs will work. We think the repairs should work, but there may be problems. The batteries were also not meant to be replaced. They should be able to be repaired, but if that repair fails, the telescope won't work at all.

We astronomers are very grateful to the astronauts who will be repairing our telescope. They are risking their lives for science. They have trained years for this one mission. They helped us fight for this mission when NASA wanted to cancel it after the Columbia disaster. We owe these men and women a huge debt of gratitude, no matter how successful the repair is.

Next stop, Hubble!

Friday, June 13, 2008

Re-opening the Pluto Controversy

A Hubble Space Telescope Map of Pluto Image Credit: Alan Stern, Marc Buie, NASA and ESA

Just when it seemed like the issue of whether Pluto is a planet or not was fading away, it was re-opened by the very body that demoted Pluto in the first place. Earlier this week, the International Astronomical Union (or "IAU" for short), the "ruling body" of astronomy world wide, announced that objects like Pluto shall henceforth be known as "plutoids." This decision was announced by the IAU working group tasked with trying to classify objects, and it was quite unexpected. Most of us didn't even know that such a term was under discussion.

The astronomers who still argue that Pluto is, indeed, a planet came out with some fairly strong condemnation of this announcement. Alan Stern, former head of NASA's science directorate and lead scientist of the New Horizons mission (a robot en route to explore Pluto), said, "It's hard to find anyone who thinks this is (i) necessary, (ii) a step forward, or even (iii) useful." From a scientist, that's pretty strong language. An article published on Space.com continues by arguing that a competing body to the IAU is needed.

Frankly, I think those involved need to take a deep breath. I agree that the phrase "plutoid" is stupid; if nothing else, it sounds stupid -- more like a medical condition than a type of heavenly body. (Imagine how you would feel if your doctor came in to a waiting room and said, "I'm sorry, Mrs. Smith, but you have plutoids.") Second, it is actually an over-classification. "Plutoid" is meant to describe icy objects beyond the orbit of Neptune that are large enough that gravity makes them round. But the existing terms "Kuiper Belt Object" already refer to small objects outside the orbit of Neptune, and "dwarf planet" was introduced by the IAU just a year or two ago to describe objects too small to be planets but still large enough that gravity makes them round. I don't know what use a term describing the intersection of these two groups is.

But the other side should calm down, too, I think. The last thing we need is another ruling body to compete with the IAU. The IAU is indeed far from perfect (I think it spends a little too much effort on bureaucracy and not enough on advocacy), but the IAU is not destroying the science of astronomy, and a second major international group would only serve to muddy the waters even more. Let's look at another oft-maligned international body: the United Nations. Most people agree the United Nations is far from perfect, but imagine how much worse the mess would be if we instituted a competing "League of Nations 2". Countries would have to choose between bodies, or maybe belong to both, and then what happens when the two bodies are at cross purposes? Or both trying to work on the same problem but spending more time arguing about who has jurisdiction? That would be worse than a mess; it would be disastrous.

Frankly, the problem is that there is no single good definition for a planet; we humans just have a penchant for trying to classify things that, ultimately, may be unclassifiable. The best classification scheme for planets may be one involving formation scenarios and gravitational interplay and past history of individual objects. But outside of our own Solar System, we have no means of determining most of these things. And even within things we all agree are planets, there are huge differences. Earth is much different from Neptune, which is much different from Jupiter. I'm sure that if Jovians existed, they would be insulted that we would have the gall to compare our puny blue rock to Jupiter's mighty bloatedness.

As humans, we've come to accept that, sometimes, there are not black and white answers, but that most answers come in shades of gray. The same is true even in science. "What is a planet?" Is a question that doesn't have a single answer, and the answer will differ from person to person, and yet all of those answers may be right. Before we go yelling at each other over what Pluto is, we should perhaps ask another question, "Does it matter?" Whether we call Pluto a plutoid, or a Kuiper Belt Object, or a dwarf planet, or a planet, or a "remarkably big chunk of ice and rock really far away" won't change how scientists view and understand the object.

Just don't call Pluto late for dinner.

Thursday, June 12, 2008

Looking For Gamma Rays

The GLAST telescope The Incredible Hulk
Image Credits: NASA / CBS

Yesterday, NASA launched a new telescope into orbit, The Gamma-Ray Large Area Space Telescope, or GLAST. I've been hearing about the preparation of this mission for at least a decade, so it is great to see it underway! My congratulations to the team.

But why would astronomers want to look at gamma rays? And don't we already have telescopes looking at gamma rays? Gamma rays are the most energetic form of light in the Universe. The wimpiest gamma rays are about 20,000 times more energetic than visible light, and there is no theoretical limit to how strong they can become (though there are many practical limits). This makes gamma rays very dangerous to living organisms; unsafe levels of exposure can cause all kinds of cancers and other nasty effects. (It was an overdose of gamma ray radiation that turned mild-mannered Bruce Banner into the Incredible Hulk at least one evening a week back in the late 1970s and early 1980s.)

Most gamma rays people encounter come from nuclear reactions and radioactive decay; gamma rays are the most dangerous form of radiation from nuclear waste. There are also gamma rays flying around you all the time from naturally-occurring radioactive elements. But, unless you are involved in a nuclear accident, the numbers of gamma rays on Earth are too low to cause much harm.

Many objects in space also produce gamma rays. Our atmosphere is opaque to gamma rays, so we are protected from this potentially dangerous radiation. But since gamma rays are produced by some of the most energetic and mysterious astronomical objects, like black holes, neutron stars, exploding stars, and the radioactive remnants of these exploding stars, we astronomers would like to study them. So we have to launch telescopes into space to look at gamma rays.

So, why don't we use the Hubble to look at gamma rays? Why spend lots of money on a totally different telescope? It's because gamma rays are so energetic, we can't look at them with normal mirrors. Gamma rays just pass right through the Hubble's mirror. So GLAST uses a very clever technique that relies on Einstein's most famous equation, E=mc2.

Behind that famous equation is the idea that matter (electrons, protons, atoms, rocks, hamsters, etc.) is just another form of energy, like light, heat, and motion. And it is possible to change energy from one kind into another. Our car engines convert chemical energy from gasoline into the motion energy of travel, as well as into heat energy (which is why the engine gets hot!). On a sunny day, the interior of that same car converts the light energy from the sun into heat energy. Nuclear reactors change some of the matter in the atomic fuel into light and heat energy. And the GLAST telescope changes the light energy of gamma rays into matter: two or more subatomic particles (and any leftover energy is turned into motion energy of the particles). The telescope then tracks the position and speed of these particles, which, through some complex but well-understood physics, lets us surmise the original energy and direction of the gamma ray.

But gamma rays are rare, and gamma ray telescopes aren't very efficient at converting light into matter. So, it is important to make the telescope big ("large area") so we can detect as many gamma rays as possible.

GLAST is NASA's second big gamma ray telescope, after the Compton Gamma Ray Observatory, launched by the space shuttle in 1991. NASA has another gamma-ray telescope in orbit, the Swift Telescope, but Swift just looks for the mysterious flashes of gamma ray light called gamma ray bursts. GLAST can detect gamma ray bursts, but its primary mission is to look for other, steady sources of gamma rays.

Gamma rays are produced by matter about to fall into a black hole. The matter gets sped up to high speeds by the black hole's gravity, and before it falls into the black hole's event horizon it can emit gamma rays that we can detect here on Earth. Energetic jets spewing from the regions around black holes can also act as atomic particle accelerators, which can create all kinds of subatomic particles that then collide and release gamma rays. The remnants of exploding stars, such as Cassiopeia A, also glow in gamma rays from radioactive elements created in the giant explosion that destroyed a dying star.

Don't expect many spectacular pictures from GLAST. It's just not possible to make sharp, focused pictures. While the Hubble Space Telescope can see details as fine as 0.05 arcseconds (an angle something like the size of a penny seen from 50 miles away), GLAST can only see as sharp as 1 arcminute (600 times worse than Hubble). GLAST would have trouble resolving details the size of a penny about 380 feet away, a feat that sharp-eyed people can do in excellent conditions. But it is still much better than the Compton Gamma Ray Observatory, which could only resolve the said penny about 40 feet away, something anyone with normal vision can easily do.

But what GLAST can't do in sharpness, it can make up for in its field of vision. While Hubble can only look at a sliver of sky about 1/80th the size of the full moon, GLAST can look at 20% of the entire sky at once!

It'll probably be a year or two before the first GLAST science not dealing with gamma ray bursts comes out. Until then, GLAST will be staring hard, catching elusive gamma rays from deep space. Let's just hope that the scientists are nice to their telescope and don't make it angry. You wouldn't like the telescope when it gets angry.

Wednesday, June 11, 2008

A good day at NASA

Today was not a good day for my blog. The first post was erased when I hit a wrong button combination, and the second one would not post because of some intermittent trouble at Blogger. Probably just some of those tubes of the Internets were stuffed up.

But, in spite of my troubles, it was a good day for the folks at NASA. The space shuttle left the space station after a successful mission (still a few days until the astronauts get home), the Mars Phoenix lander managed to shake some dirt into its oven (causing some scientists to dance to the tune "Shake Your Booty," the video of which will undoubtedly embarrass their kids for eternity), NASA's newest space telescope, GLAST, launched successfully, and NASA's New Horizons mission to Pluto crossed Saturn's orbit, becoming the first spacecraft to venture further away from home in 27 years, when Voyager 2 passed Saturn.

I tried to watch the launch from my computer, but about a minute before launch the internet feed stopped. By the time I reconnected, the rocket was already over a minute into flight. Dang Internets tubes must be really blocked today.

test

testing to see if posting is working.

Monday, June 09, 2008

Astronomy social networking

People don't come to me for advice on social networking, and for good reason. There are deep sea sponges that are more outgoing than I am. But astronomy is becoming more and more accessible through online networking, and I learned about several such endeavors while at the American Astronomical Society meeting last week. So, here is a completely incomplete list of a few options for a few popular social networking sites. Network away! And, if you have any good suggestions for further networking, let people know in the comments below. (Astronomy-related only, please, and no spamming or adverts -- I'll check up and delete anything else with extreme malice.)

Like any good networking, these are starting points to use to branch out to even more interconnectedness.

Twitter:

  • MarsPhoenix -- a first-person update on the Mars Phoenix Mission, sent to your desktop from Mars.
  • astronomy2009 -- Updates on the 2009 International Year of Astronomy
  • BadAstronomer -- Phil Plait, the Bad Astronomer, one of the better online outreach people this science has
(Yes, I'm on Twitter, but under yet another pseudonym, and unless you want daily updates on my grocery list, you don't want my tweets.)

MySpace:

Facebook: I'm just getting started exploring MySpace, and don't exist there yet (though my mild-mannered alter-ego does). But I do know of a few astronomy-related groups, such as:

So, get networking! Show me up! (Not too hard to do...)

When We Left Earth

Apollo 11 launches in July 1969
Image Credit: NASA

Last night I watched the first two hours of the Discovery Channel's new NASA documentary, "When We Left Earth," a high-definition (and somewhat starry-eyed) look at NASA's first 50 years of manned spaceflight. Last night covered the Mercury and Gemini programs; next week will cover the Apollo moon exploration program, and in two weeks they'll cover the space shuttle. I thought it was a good documentary, and somewhat timely, as our first astronauts are aging all to quickly, and everyone my age and younger was born after the last moon landing. Alas, I don't have high-definition cable channels (I'm too cheap), so I missed the full impact of the program.

If you missed the program, I'm sure there will be re-runs; if you don't get the Discovery Channel, the DVD is already on sale (and probably available for rental).

It is easy to forget how little we knew about space just 50 years ago (Would the astronauts be able to swallow in space? Would Evel Knievel had been a better astronaut than Niel Armstrong?) and easy to forget how dangerous spaceflight really was and remains. And, as NASA prepares to send humans back to the moon, these are lessons we need to remember.

Friday, June 06, 2008

A new map of our home galaxy

A new map of the Milky Way Galaxy
Image Credit: NASA / JPL-Caltech / R. Hurt

Since the dawn of astronomy, humans have been trying to figure their place in the cosmos. These days, we know that our Earth goes around the Sun, which is a pretty normal star. We also know that our sun is one of ten billion stars that make up the Milky Way galaxy, a disk-shaped group of stars all revolving around the center of the Galaxy. That much alone took us until the 1920s to really figure out. But what does the Milky Way galaxy look like, and where are we in that Galaxy? We've slowly figured some things out (like that we are 25,000 light-years from the center of our galaxy, and that our galaxy is a spiral galaxy), but the details have been slow in coming.

This is because it is hard to map our galaxy. Unknown amounts of dust block our view along many lines of sight, and different data sometimes seems to give different answers. It is a lot like trying to figure out the shape of a forest while standing in the middle of it and not being allowed to move. But, at this week's meeting of the American Astronomical Society, a team of astronomers presented a new map of our Milky Way galaxy that represents the best collection of data we have to date.

In this map, (pictured above, but better seen at today's Astronomy Picture of the Day) the spiral Milky Way has lost a couple of spiral arms -- what we thought were a couple of arms are actually partial arm-lets in between the two biggest arms. And this is a good thing. Most spiral galaxies only have two arms, so it seemed strange that ours had three or four. Now we know that our Milky Way is a pretty normal-looking spiral galaxy.

This map may well change in details as we learn more in the future, but it comes a long way from William Herschel's map of the Milky Way just 200 years ago. But, should you ever get lost on an intergalactic cruise, our new map may just be good enough to get you home.

Wildfire update

Image Credit: David Doss / McDonald Observatory

For right now, it looks like McDonald Observatory is not in danger from the Hughes Ranch Wildfire that is burning in west Texas, although some other historic structures and houses in the area unrelated to the observatory are threatened. However, if the wind changes direction and picks up (neither of which is expected), things could get hairy very fast.

The fire was started by a nearby railroad line, though explanations differ. One group claims a passing train wheel sparked into the high, dry grass, while another group claims it was a spark from a welding torch during track repairs. The initial fire threatened the railway crew, thankfully nobody was hurt.

Thursday, June 05, 2008

Wildfire near McDonald Observatory

We've just heard that there is a grass fire that has consumed 20,000 acres about 15 miles away from McDonald Observatory. I haven't heard if the observatory is threatened or not, but I suspect I would hear if they were worried.

However, there is a lot of very dry grass and tinder around the area, because it rained a lot last year, but has been very dry ever since. The telescopes worked last night, so the smoke can't be too bad. (Smoke is very bad for telescope mirrors, because it contains corrosive chemicals. So we close up tight when smoke is around.)

I'll write more if I hear more. In the meantime, here is a news story about the fires.

The smallest planet ever found? Sorta, kinda, maybe, not really...

Image Credit: D. P. Bennett / The Astrophysical Journal / arXiv.org

Some times you get lucky, sometimes you are unlucky, and sometimes you get lucky and unlucky at the same time. The latter is the case for astronomer David Bennett of the University of Notre Dame's Department of Physics. Dr. Bennett is involved in a search for gravitational microlensing. Microlensing happens when one star (the "lens") passes between the Earth and another star. The gravity of the lens star focuses the light of the more distant star, causing it to appear brighter from the Earth. The amount of brightening and the length of the brightening tells us about the lens star and the background star, and any strange features can tell us about companions (be they other stars or planets) of either the lens or the background star. There are many ongoing searches for these microlensing events.

At the American Astronomical Society meeting on Monday, Dr. Bennett and his collaborators announced that a search they are involved with, the Microlensing Observations in Astrophysics search (or "MOA"), had discovered a microlensing event that showed some strange things, which they interpret as a planet three times the mass of Earth circling a very tiny star (or perhaps even a brown dwarf, or a star too small to shine by its own nuclear reactions). This planet would be the smallest planet known around a star (except for planets known to be circling pulsars, the remains of a supernova explosion). This could be an important discovery, because it would show that even the smallest stars can have planets.

This is a lucky discovery, because microlensing requires luck -- you need an interesting star to either go in front of another star, or to have another star go in front of it. And you have to be looking at the right place at the right time, as there is no warning that something cool is about to happen. And you need automated telescopes that can search the sky on every clear night, that can automatically analyze pictures and look for a star getting brighter in the manner that indicates microlensing, and that can then automatically follow up that star as often as possible. It's not easy; the fact that astronomers can do it is a feat of both teamwork and computing power.

So, why do I say that Dr. Bennett is also unlucky? Look at the graphs at the top of this blog entry. The red and blue points mark when telescopes took pictures of the object, and the different colors of curves show what different types of microlensing events might look like. Some need planets, and some don't. Notice the problem? There are several hours when no pictures were taken, and many different types of microlensing can fit the data Bennett did get. During the hours most critical to interpreting the microlensing event, it was either daytime or the weather was bad.

This doesn't mean all is lost. In a long paper, Dr. Bennett and collaborators go through an extensive amount of models and testing and estimating, and they show that their interpretation, a tiny star with a super-Earth in orbit around it, is the best model that they tested. I am not experienced in interpreting microlensing, so I have to take them at their word, and the paper did pass a review by an independent scientist. But many of the planet people I know are dubious. They want to see more proof (such as the missing points, which it is now impossible to get).

Thankfully, there are some ways using large telescopes and the Hubble Space Telescope to try and get more information on both the lens star (the one with the planet) and the background star. A lot more hard work should be able to help settle whether this small planet is real, or whether there is some other explanation for the observed microlensing event.

Wednesday, June 04, 2008

Travel Excitement

Yesterday, I left the summer meeting of the American Astronomical Society behind to come home. The meeting is still going on through tomorrow, but I finished my contribution on Monday and had work to catch up on at home. My intent was to get home in the mid-afternoon, catch up on the Tuesday news from the meeting, and then write a little blurb on that. But my airline (which shall remain nameless to protect the guilty, but let's pretend it was called "Shamerican") had other plans. My flight was supposed to leave Saint Louis at 2:05pm, which came and went uneventfully, meaning I was sitting in the gate area not hearing a peep. First we were told that the plane was being clean (which I believed, since it arrived late), but after twenty minutes, I stopped believing that. I've never been on a plane that clean. At 2:20pm, we got word that maintenance was still working on the plane, and that we'd be boarding no later than 2:45. At 2:45, we were told that maintenance was about done. In the meantime, I was called to the desk and given a new seat because my original seat (an emergency exit seat) was broken. So I assumed that the mechanical problems had to do with the seat, and that they'd decided they couldn't fix it. Wrong.

Finally, at about 3pm, we boarded. It was one of the regional jets operated by Shamerican's partner, Shamerican Shconnection, so it didn't take long to board. It was hot in the airplane, though, because the A/C was off. I assumed it would get cold once the engines were on, as this has happened to me many times before. We pushed off from the gate and took off.

Shortly after takeoff, I suspected something wasn't right, because my ears were popping much more than normal. But these partner airlines often seem to have trouble getting the airplane pressure dialed in, so I figured they'd get it right and all would be well. Wrong again.

We turned to the south to head to Austin and levelled off at 5,000 feet or so (again, common until air traffic control says we can go up to the cruising altitude). But we didn't go up, and then we turned back to the east. And the pilot came on, apologized, and said the cabin was unpressurized, and we had to go back to St. Louis and get it fixed. He hoped that the maintenance had just forgotten to connect some hose after their earlier work.

I wasn't worried at this point. The plane was flying just fine, and we were at a low enough altitude that the unpressurized cabin was not dangerous. We had to dive down to the runway, but we landed fine and taxied to a new gate. (Meanwhile, the A/C was still not working, and it was really hot and stuffy on the plane.)

After we were at the gate 15 minutes or so, we were told that they couldn't fix it right away, and we had to get off. The pilot ominously said to stay in the gate area, and that they hadn't cancelled our flight "yet."

Thankfully, at this point, the story improves. The airline gave us a different plane, and we all boarded and took off for Austin at about 5pm (only one hour after we were already supposed to be back). Two hours later, we were in Austin, where we had to wait 15 minutes for our gate to clear. No matter that the neighboring gate was open with no incoming flight. Whatever. We were happy to be back safely.

Our pilots, flight attendant, and the in-airport gate crews at St. Louis were all very polite and helpful, and I know these problems weren't their fault. I am a little miffed that the maintenance had been working on the plane and didn't get it right. I'm more miffed that I know that I won't get a word of apology from the airline. I know these things happen, I know we were never in mortal danger, and I know that I got home eventually. I can accept that. But rather than forcing the pilot and gate crew to give out apologies for things that are not their personal fault, I'd like an apology from the party with the ultimate responsibility, the airline. Southwest Airlines follows up incidents like ours with personal, written apologies.

I don't care about getting some additional compensation or free food or extra frequent flier miles. I would just like some admission from the larger corporation that we, the customers, mean more to them than just dollar signs. At a time when the airline business is suffering, such an acknowledgement might make me more amenable to their situation and more willing to put up with increased fares or inane new charges like bag-checking fees. But the deafening silence the customers get from the truly responsible party (the airline, not their employees who have no fault in the issue) when problems arise makes me less happy to put up with their shenanigans.

I'm not asking an airline to cater to my every whim or to offer unreasonable compensation levels. A simple, honest "we know this happened, it shouldn't have, and we're working to keep it from happening again" would be enough. Yet I know I won't get it, though I will be asked to fork out even more cash for even worse service in the future. And that angers me.

Monday, June 02, 2008

Meet me in St. Louis...

The Gateway Arch in St. Louis

Greetings from Saint Louis, Missouri! This week is the summer meeting of the American Astronomical Society, the smaller of our two annual meetings. Astronomers from around the country have descended on St. Louis in order to discuss our latest research, reconnect with old friends, and hopefully meet some new people.

This week's meeting also includes members of the Astronomical Society of the Pacific, a collection of both professional and amateur astronomers. Much of the summer meeting is dedicated to planning and discussion about next year. Why? 2009 has been designated as the International Year of Astronomy, and so many special events are being planned to celebrate the 400th anniversary of Galileo's first astronomical use of the telescope, which we will use as a reason to promote space science to the general public.

My stay here will be short. I have a presentation this afternoon, and I'll be heading home tomorrow. The meeting continues through Thursday. So, you can expect to see some press releases about new and interesting research coming out of St. Louis this week! I'll try and bring you what inside information I can.