April 30, 2012 at 8:27 am | Leave a Comment
What They Say About Themselves
Last week, I was a guest speaker at StarFest, a Denver-based Sci-Fi Con that regularly draws several thousand folks. I usually talk about astronomy topics and this year was no exception. My main talk was about Pluto (and its dwarf planet status), and I also participated in a panel discussion about hoaxes — astronomical, planetary, and paranormal. The Pluto talk went really well, and the crowd was really into the whole story of its meandering progress through planetary status.
Pluto is a dwarf planet, a status that is not a bad thing. I’ve said before that giving it the “dwarf” nomenclature tells us something about its evolution, its place in the solar system hierarchy, and even gives us a clue about our own understanding (or lack thereof) about the details of Pluto’s composition and history. It’s not terribly different from looking at a dwarf galaxy and wondering what that “dwarf-ness” means. A dwarf galaxy is NOT a wanna-be galaxy. It’s not a consolation prize. It’s a status that helps astronomers understand the evolutionary state of such collections of stars, as well as other characteristics such as the metal content of their constituent stars (and the materials those stars formed from). Dwarf galaxies are small, usually containing up to a few billion stars, and they are implicated in the evolutionary process that forms larger galaxies. Right now, dwarf spheroidal galaxies are being sucked into our own Milky Way Galaxy or are orbiting nearby.
There are also dwarf stars which comprise the main sequence (a classification scheme that lumps stars together by their color and brightness). The Sun is a dwarf star, for example. There are red dwarfs, yellow dwarfs (the Sun), blue dwarfs, white dwarfs, and so on. The most fascinating ones (to me, anyway) are the brown dwarfs. These are not actually stars like the Sun, but are really sub-stellar objects. They’re not massive enough to fuse hydrogen into helium as most other stars do, but they do have enough mass to fuse deuterium (an isotope of hydrogen) in their cores. The masses of brown dwarfs range from about 0.08 solar masses and more than about 13 Jupiter masses.
Where do brown dwarfs come from? Their origins are still really not well understood. Whereas astronomers can trace the beginnings of dwarf galaxies in the early universe, and we think we kind of know where dwarf planets come from in the evolutionary history of the solar system, the formation of brown dwarf substellar objects is still a hot topic in astronomy. Some astronomers think that they are born much like stars are born, through the collapse of interstellar gas clouds. Low-mass clouds might be yielding l0w-mass objects. Others suspect that brown dwarfs form in larger clouds along with stars of various masses, and that the brown dwarfs are ejected from their birth places in gravitational interactions with their higher-mass siblings.
Only a few hundred brown dwarfs have actually been observed, so as astronomers find more of these objects that are too cool to be stars and too hot to be planets, they should get a better handle on the environments in which they formed. And that will tell them more about brown dwarf formation throughout the history of the cosmos. So, as with Pluto — which is going to help planetary scientists understand the worlds of the extreme outer solar system — brown dwarfs may help shed light (no pun intended) on what is still a little-understood population of objects that form in interstellar gas clouds.
April 28, 2012 at 21:34 pm | Leave a Comment
Hubble Space Telescope’s 22nd Anniversary and Me
This past week marked the 22nd anniversary of the launch of the Hubble Space Telescope. It really is hard to believe all that time has passed, but the solid record of science achievements from this famous orbiting telescope is proof that even if you start out with a problematic telescope, you can still do good science. Of course, making Hubble DO that good science took squads of astronauts, ground-based technicians and scientists years of problem-solving to do. But, they did it.
I was not quite in graduate school when Hubble went up on April 24, 1990. I’d been part of a science team at the University of Colorado for just over a year and a half, led by Dr. John C. Brandt, who was (at that time, among his many responsibilities) the co-Principal Investigator for the Goddard High-Resolution Spectrograph instrument onboard HST. I was working on a project analyzing Comet Halley images; specifically, I was doing astrometry on images of the comet’s tail so that we could analyze how the tail was being affected by the solar wind as the comet rounded the Sun during its last close approach in 1985 and 1986.
Not long after launch, Jack came back from Goddard Space Flight Center and warned us that there could be some problems with the telescope. I think that only a few people knew how bad the problems were, mostly because they were still analyzing the images and calibrating the telescope. But, in June 1990, the full news broke and people were devastated by the idea that HST was flawed. I know we at the university were.
But, even as early as August of that year, we were seeing images that didn’t look awful, and I knew from talking with Jack that there was good science to be had — even if it took a bit longer to analyze the images. Our instrument, however, was pretty badly affected, as was the Faint Object Spectrograph. I started to make notes about the problems with the telescope, and paying attention to the images it was producing. I think I had some idea that I’d write a book about the project someday and I knew it would be good practice to keep notes from the early days. In the meantime, I plugged away on the Comet Halley project, which eventually got published in 1992 as the International Halley Watch Atlas of Large-Scale Phenomena (Brandt, Niedner, and Rahe, with mucho work done by me in a small-credit role).
Well, after that one thing led to another—I studied MORE comets as part of the Ulysses Comet Watch, and I entered graduate school and joined Jack’s GHRS team (albeit as a very junior member). The science flowing from HST was getting better and better, and the first servicing mission proved that the telescope could be brought “up to spec”. So, I decided to shop around the book idea, and took Jack on as a co-author. After a false start or two, we ended up signing a contract with Cambridge University Press, and in 1995, we published Hubble Vision, which was updated a few years later. I also did a planetarium show by the same name, which has been a mainstay of my company’s repertoire ever since (read more about that show here).
I feel like I kind of grew up with Hubble, or maybe we grew up together. I feel privileged to have worked on an instrument team for HST, and to have written about it as extensively has I have. The telescope has for me–and I hope for all people who follow astronomy exploration–expanded the horizons of cosmic understanding. And that’s a great tribute to its 22 years (and counting) legacy!
If you haven’t taken time to browse the images at Hubblesite.org, take some time to do so. The very act of exploring those pages is a voyage of exploration of the universe.
Check it out!
April 18, 2012 at 11:00 am | Leave a Comment
A Look Ahead
In remarks given after space shuttle Discovery landed at Dulles airport yesterday, Deputy NASA Administrator Lori Garver gave onlookers a sense of where NASA is and where it might be headed now that the space shuttle program is no more. She rightly pointed out the many accomplishments of the shuttle program, and she even acknowledged some of the melancholy flavor of the end of the shuttle era. “To those who say our best exploration days are behind us, I must disagree,” she said. “While it is wonderful to reminisce about the past, NASA continues to focus on the future. You need only admire the amazing space shuttles and their accomplishments to realize the people, organizations and nation that created them have only just begun. Vehicles with names like Orion, Dragon and Dreamchaser are being built all across the country today. They will continue and expand on the space shuttle’s many accomplishments.”
She went on to talk about asteroid visits and Mars exploration, and how those programs might enhance jobs and technology. If all this happens, then perhaps the future is not so gloomy as it seems. Although I’m waiting to see how the promise of the upcoming launch vehicles and our future as astronauts plays out, at least there’s some sort of plan in place, even if it doesn’t give our country its own launch capability for crewed exploration for a few years yet. But, the real proof of the pudding will be in whether or not the funding is made available to make all of it happen (and more). And, that’s where things get dicey.
In my last entry, I pointed out that Congress (representing the people, supposedly) has to make the money available. And, that’s where the guts comes in. I don’t think there’s much in the way of guts in our representation right now. If people WANT a space program that is robust, and we make our voices heard, supposedly Congress will do the will of the people. But, I’m skeptical, since the Congress we all know today seems to be more about bowing to narrowly defined special interests and corporate lobbyists that do NOT seem to have people’s jobs and future in mind. I often wonder if we ALL made a huge fuss about increasing NASA budgets, etc., would Congress listen?
So, let’s say Congress gets its act together and starts doing something positive for NASA (and not the markup battles that are going on this week). What ARE we looking forward to in a long-term space program? I began reading through a National Academies of Sciences report called Recapturing a Future for Space Exploration, published in 2011 and available here (you can read it free online). And, based on what I’ve read so far,there’s a very broad mandate that cuts across all disciplines of science. To reinvigorate NASA (as it says in the report), it will take all sciences, pulling together, to focus our space program on the challenges of the future, whether here on the ground or in low-Earth orbit, or on the way to Mars. For example, the report looks forward to human exploration of space, and the many challenges it will make on the physical bodies of our astronauts. It talks about the issues involved in searching out habitable places on the Moon and Mars, and the technical challenges of getting to those places and surviving there for long periods of time.
Of course, all the sciences involved in space exploration are supported by and support various industries and agencies, and those require trained people to do the jobs needed. And, that raises a question of where the training is going to happen? It’s been widely known for a long time that our country (the U.S.) is having problems in attracting more people to the STEM (science, technology, engineering and math) disciplines needed to do the jobs. In short, in many places, education is letting us down. Or, to put it more properly, support for science education itself is being let down. In part, that’s because our education system has been gutted and manipulated by non-educators with political axes to grind. The result is showing up in poorly trained students and a workforce that will not be ready to meet the challenges we face. Where we will get the people to take those future jobs in space and other technological industries and disciplines is a mystery that we as Americans will need to solve. The people who are in science research NOW are holding the line on our decline in science interest, but what happens when they retire? Will there be new folks to step into their shoes and take up the cause of our space program and all the good things it does for us and our economy?
Where do we start?
Before anything else we do, I would love to see education removed from the manipulations of the political arena. I am reminded of a saying I saw on Facebook the other day: those who can’t teach make laws regulating those who can. It seems to be very apropos. Let teachers do their jobs, remove the meddling politicians and their ilk from the classroom, and stop screwing around with the teaching of science, as they are trying to do in Tennessee and other places where proud ignorance overcomes pragmatic common sense, and people with NO knowledge of science feel that it’s perfectly fine to meddle in things they don’t understand.
Our future in space needs well-trained motivated people who have received an education that promotes science inquiry. These people are the key to a future that lifts us all up, and that’s where we should all be headed. The NAS report I cited sketches out a great future, but the weak link to everything we want to become is education. And, it’s a link we need to defend from the forces of ignorance and wilful stupidity. We did it once before, and if we care about the future, we will be able to do it again.
April 17, 2012 at 14:30 pm | Leave a Comment
But We’re Saying GoodBye to a Once-Active Part of It Today
Today is a bittersweet day for space buffs. The space shuttle Discovery left the Kennedy Space Center for the last time this morning and a few hours later made its victory lap over Washington, D.C. before settling down on the runway at Dulles Airport. It now begins its retirement at the Smithsonian’s Udvar-Hazy complex near the airport, as an exhibit. It was a thrill to see the shuttle (mated to its carrier 747) swoop over the D.C. area in a graceful display of our hopes and dreams in space. Look at the pictures below, and you’ll see not just Discovery, but the people who came out to watch her final descent. People who wanted to see something special, people who realized this was the passing of something special. It meant something to them.
Those hopes and dreams are going in a different direction these days. Ever since President Bush announced in 2004 that it would bring the program to a close and signed directives to that effect, we’ve known this day was coming. Still, it’s sad to know that the shuttle program is really coming to an end. Yet, it didn’t have to be this way. In the years since then, NASA should have had the funding and support to come up with a new means of getting to space that improved on the shuttle program.
Instead, we have begun work on what looks like an Apollo-style program that is withering on the vine, being jerked around by political considerations. The companies working on it are doing the best they can, and I wish them the best. But they have a rough row to hoe, reinventing wheels that NASA people were raised to perfect long ago.
NASA’s other missions of planetary exploration, education, and research are also suffering, getting just enough money to keep stayin’ alive, but not exactly thriving. Tax cuts or not, NASA programs create JOBS and pride; two things that Wall Street lobbyists, Teabaggers, wingnut politicians, anti-science bigots, and many others either just don’t get or just don’t really care about.
But, many, many people of our country DO care. The space program is part of our national psyche, something we’ve always been proud of. Just look at the faces of the people who lined D.C.’s roads today, flocked to viewing sites, and took millions of images and videos to post on the Web and Facebook and Flickr and other sites, and tell ME they don’t care. It excites them.
The political hacks who are helping to “ungrow” our space program one program at a time are mocking that excitement; worse, they’re mocking a thing that makes many Americans feel good about what we can accomplish if we set our minds to it. They’re mocking fellow Americans, and that seems almost traitorous.
Don’t get me wrong. I know that we had an aging shuttle fleet and that it would have needed to be retired sooner or later. That’s the nature of technological change. And, for the record, I doubt there’s very much the current administration could have done to resurrect the shuttle program. By the time President Obama took office, the shuttle program was too far gone to bring back. The relevant work needed to be done well before Bush left office. A new program that built on the success of the shuttle, rather than going back to “spam in a can” designs should have started up as soon as Bush signed the warrant killing the old one. But, that didn’t happen, and so today, we have our last shuttles becoming museum pieces. And, not to put too fine a point on it, but Congress (more so than the President) bears a HUGE responsibility for funding for NASA. Congress has not met that responsibility; indeed, rather than admit that, some members prefer to finger-point away from themselves, blaming the President or anybody else even as they gut the NASA budget. Hypocritical much?
The good news? We still have a space program, but one that is being gutted by science-intolerant hacks intent on wrecking government in order to save it. Our space program, which costs YOU and ME (if you’re a U.S. citizen) LESS than half a cent apiece, is a job creator. It’s a technology incubator. It educates. It inspires. It returns MORE to our economy than it takes in. It feeds the future, which is something we need. It shouldn’t be ripped to shreds by politicians in Congress who waste their taxpayer-paid salaries and gold standard benefits (that WE pay for) creating and wallowing in ugly political pigsties in order to get elected (or re-elected). Perhaps if we didn’t vote for people whose only intent is to destroy jobs and technological innovation in their efforts to pander, things would change. But, that’s a rant for a different day.
Today, let’s focus on the beauty of what our space program does provide: some of the most gorgeous insights into our cosmos that anyone on Earth has ever been given. That’s priceless. You can’t put a value on it, or what it does for the human spirit. Or what it pays forward in terms of knowledge and advancement in fields as diverse as biology and medicine and chemistry and physics, astronomy, and technology.
Yes, we can acknowledge the graceful beauty of the shuttles, the sadness of their passing, as is entirely right and proper. It is the end of an era and all such ends should give us pause to reflect on what we have accomplished and what remains to be done.
But, let’s also look at what our space program still offers us. For example, this gorgeous view of star formation in a nearby galaxy, released to celebrate Hubble’s 22nd anniversary of its launch to Earth orbit.
This is what investment in scientific knowledge gets you on the front end — the technological savvy to take pretty pictures AND explain them and relate them to our lives here on Earth. That kind of research IS an investment, and it pays off HUGE dividends on down the line. We just have to focus the attention of our leaders, to help them see their way clear to reupping and maintaining that investment.
April 5, 2012 at 12:08 pm | Leave a Comment
Dust Devils Just Keep on Dancing Across Mars
Okay, a few weeks ago we had a week’s worth of high winds where I live, typical for Colorado in the late winter. We call ‘em Chinook winds, and they tend to dry things out as they blow at speeds upwards of 70 to 90 mph (112-144 km/hour) and gusts up above 100 (160 km/hr). That’s all part of a weather pattern that occurs here, and in other parts of the world as the seasons change. Right now, as we saw in Texas a few days ago, the winds and the associated weather patterns whip up twisters, tornadoes, dust devils.
The winds blow on Mars, too, and the Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment (HiRISE) camera has been very good at spying out Martian dust devils. Unlike a tornado which we see here on Earth, a dust devil typically forms on a clear day when the ground gets heated by the Sun. That warms the air just above the ground, and that air rises quickly through a small pocket of cooler air above it. If the conditions are just right, the air can start to rotate, and as it does, it picks up dust. This is a frequent occurrence on Mars.
On March 14th, HiRISE caught sight of a Martian dust devil roughly 12 miles high (20 kilometers) whirling through a region called Amazonis Planitia. The dust devil about (70 yards, or just about 70 meters across). The image was taken during late northern spring, two weeks short of the northern summer solstice, a time when the ground in the northern mid-latitudes heats up in the sunlight.
One of the cool things about these dust devils is that they scour the ground of dust, leaving behind a thin, sinuous little path. When those little paths were discovered, their appearance and cause was unknown. It didn’t take long for scientists to connect them with the appearances of dust devils. It appears that these dust devils are one mechanism by which dust gets redistributed around the Martian surface.
Check out the full story and a very cool animation showing what the dust devil might look like from the side at the NASA Mars Reconnaissance Orbiter page. It’s full of wooty Mars goodness! And, if you experience winds and dust devils where YOU live on Earth, then you have a good idea of what it’s like on Mars when one goes twisting by!
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Copyright 2013, Carolyn Collins Petersen
Image of Horsehead Nebula: T.A.Rector (NOAO/AURA/NSF) and Hubble Heritage Team (STScI/AURA/NASA)
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