Space dust: Your tax dollars at work

Your tax dollars build bridges. They pay the salaries of teachers and firefighters. Tax dollars help put people through college, provide a safety net for the elderly and the disabled, and pay for fighter jets and nuclear bombs.

You may not agree all those ways your tax dollars are spent, but they are all, at least, fairly tangible. When it's time for re-election, your senator can point to a roads project, a school, a saintly grandmother, or a missile silo. Through these projects, Americans are being educated, cared for, and protected.

But it's hard to make that clear cost/benefit analysis for basic scientific research. At least, not on a timetable that matches up with election cycles.

Basic research is often weird, and it's often boring. It's the years spent mapping the neurons of zebra fish, so that future scientists can have a more detailed biological model to work with. It's the chemical analysis that has to happen, so that two decades from now somebody else can discover a new cancer-fighting drug. Basic research is about curiosity, and knowledge for knowledge's sake. By it's very nature, basic research relies on public funding. But by it's very nature, it's hard to explain how the public benefits from the basic research we fund.

Attila Kovacs is one of the scientists who put your tax dollars to work. An astrophysicist at the University of Minnesota, he specializes in the study of space dust. That is, yes, dust. In space. It's the sort of thing that would be very easy to mock. (Imagine Bill O'Reilly making a joke about lemon-scent space Pledge.) But Kovacs says space dust matters more than you think. And he makes a good case for why it's important to spend tax dollars on funny-sounding science.

Maggie Koerth-Baker: You study space dust, but what does that really mean? Is this the same thing as dust on Earth, just in space? Or is space dust something a little different than the stuff that builds up on our bookshelves and end tables?

Attila Kovacs: In some ways it is similar. I like to think of Earth as a giant dust ball. Earth was made of space dust, but it went through a lot of evolution so dust that’s on Earth now isn't exactly the same. We don't actually know the structure of space dust, but we can guess. It probably has metallic core surrounded by a carbon or silicate shell and an ice mantel. They may be shaped like snow-flakes or a crumpled piece of paper. And we know that a typical speck of space dust is about 0.1 microns, about 1 thousandth of the width of your hair. It's hard to get your hands on space dust. We can only get indirect evidence through observation, by looking at the light that goes through the dust.

For instance, we know the size of space dust because light that has a wavelength larger than the particles of dust has come through the dust. We can see how different wavelengths of light either get blocked or go through the dust layers and we can put a size on that.

But what really makes dust interesting to me is its intricate connection to star formation. Dust is produced by stars in their dying phase, and it's also an essential ingredient for making new stars and planets. Interstellar dust is mostly heated by massive young stars less than a million years old. In fact, most of the light from stars is absorbed and re-emitted as heat by dust. So, by measuring the heat contained in dust we can get an accurate picture of the current level of star-formation in galaxies at all ages of the Universe. Through the dust, we can directly measure the complete star-formation history of the universe and get a glimpse at when and how the galaxies and stars came into being. This is what I research.

Yet another interesting aspect of space dust is its role in the chemistry of space. Most molecules, including molecular hydrogen, water, CO, and even some organic compounds that we see in space, have formed on the surfaces of dust grains, which act as catalytic surfaces enabling chemical reactions at the low temperatures and densities of space. There is no other way to make such molecules. All the precursor organic molecules of life on Earth probably formed on dust grains around a dying star, before our Sun and solar system were even born.

A scanning electron microscope image of an interplanetary dust particle. CC licensed, via Wikipedia.

MKB: When did you decide to dedicate your life to studying space dust?

AK:
I was drawn to astronomy from a very young age. Soon after I learned to read, my grandmother took me to a bookstore, and told the clerk to get me whatever book I wanted. I told him I wanted a book about astronomy. The clerk got me something appropriate for a child of age 6, with pretty drawings of a smiling Sun and all, but I was very upset. I told him I wanted something much more serious. In the end, we settled on a book that would be your college-level intro astronomy. I loved it. I did not understand it all, but I still loved it. Later my interests turned to physics. But physics was a pretty dry landscape. A lot of the really crazy discoveries go back to the beginning of 20th century. Astronomy is always new and exciting. Every time you turn on a new telescope, there's always something new you’ll discover. That's what drew me back to astronomy.

As for dust, dust is the most prominent thing that you will see in space, even more than stars and star-light. More than half of all the light from galaxies in the universe is radiated as heat from dust grains. It’s also the most critical ingredient in the chemistry of the interstellar medium.

MKB: I’m assuming you’re not the only person studying this stuff. What makes your approach different? What aspects of space dust are you looking at that your colleagues aren’t?

AK: To some degree all of us are doing somewhat different work, but that doesn't mean there's not overlap. But I think it's important to have that overlap. That's where you get the credibility of science. Without that
there’s no way to check whether somebody is right or wrong. Redundancy is a cross check.

What I personally do different: We do the same sort of observations. When I get observing time to look at a few galaxies on a telescope, there are people doing similar observations. But what's unique about what I do is the models that I use for analyzing the data and the tools I develop. Most astronomers who observe similar subjects are really users of technology. They use what's there. I, on the other hand, try to think about what will be the next gadget we can bring to the telescope that will enable us to do this research even better. I don't know a lot of people in the “dust” community that do that.

For example, I’ve worked to develop the equivalent of digital cameras for this long wavelength light, that lies between the infrared and radio bands. Essentially, they’re very sensitive thermometers. When you put them on telescopes then the light from the distant galaxy heats up the detector and you notice this very small temperature change. The instruments I helped to build are used on telescopes in Hawaii, Chile and Spain. And more recently I had an interesting idea on how to build an instrument that would split that light into 1000 different colors for each pixel, and then you can take pictures of both the dust and the dominant chemistry in galaxies. You can get a vast amount of information from that because you will be able to detect and map dozens of molecular lines in distant galaxies all at once. I’m hoping to build such an instrument and get it and on a telescope in a few years.

MKB: That sounds expensive. How do you fund this research? Who funds it, and how does that process work for you?

AK: We're relying a lot on government agencies, particularly the NSF (National Science Foundation) or NASA. And there are two ways to get funding. First is through regular grant projects, which are 3-year cycles where you apply for a grant to do specific research. And NASA also provides funding to use their space telescopes. So you can propose to do a specific bit of science with them and if you get observing time then they'll give you some money to help you with that.

The process starts with a proposal. You tell them what you want to do, why it's important, and what you hope to learn. You really have to justify your work. They don't just give you money because it's nifty. The grants are peer reviewed. And your peers decide whether it merits funding or not. They look at what you've done before with funding. They look at the potential impact, and what you'll do to communicate your science to the public. This is how they select who gets the funding. Typically it's for a 3 year cycle. Every 3 years your whole life hangs in the air. And it's far from guaranteed. Most things I apply for, 1 out of 20 or 1 out of 100 proposals are successful. It's far from easy.

Pig at the Minnesota Tax Cut Rally 2011, a Creative Commons Attribution (2.0) image from fibonacciblue's photostream.

MKB: How expensive is your work? When you do win these grants, what does the money go toward?

AK: At the bottom level it's the salary. I get around $40,000 and when you add overheads and whatnot that the university pays, it’s maybe $70,000. To do the science we have to build the instruments. We can't just use our eyes on the telescope, and those tools typically cost a few million to develop.

Then there’s the telescopes themselves. A 10 meter radio telescope up on some high mountain, that’s maybe $10 to $15 million to build, and a few millions a year to run. Private donors often pay for the construction of telescopes that will bear their name — like the famous Keck telescopes in Hawaii, paid for by W. M. Keck. A space telescope can be upwards of $1 billion.

That’s expensive. But you have to think of what it costs to the typical taxpayer. With just a single dollar of tax you pay every year, how much can you buy when it’s combined with the $1 everyone else pays? For $1 per person every year, you’re going to pay for 2000 post-doc researchers. That’s 2000 people like me. Or you could buy up to 100 instruments to put on the telescopes. Or your $1 can also buy you a few telescopes a year or one space telescope every few years.

MKB: You do basic research, stuff that’s really driven by curiosity, not by short-term practical goals. In a time of tight budgets, why is that important? In a recession, is space dust really something we can afford to spend money on?

AK: These are difficult times and when the money is tight we have a tendency to ask whether this is practical, and do we really need it. The answer to that is that it's not the need that drives discovery. It's the other way around: discovery drives our needs. You can only need things that you already know about. What basic science does is look for new knowledge. What it will be made of in the future, we don't know. But often it brings us new things that will be very practical.

My favorite example is electricity. Electricity, when it was discovered, wasn't anything useful. But once it's discovered, then you can start thinking about how you'll use it. What you have to think about is this: What is practical is something very short term. Basic science is much more forward looking. Some of it will produce useful things 10 to 30 years from now.

If you’re tight on your own budget how do you trade off on everyday necessities versus saving for retirement? You can't pay for rent and food at the cost of not saving at all for retirement. So when the budget is tight you have to cut back on both ends, rather than eliminating one. And we should do that in science. You can’t sacrifice the future because times are bad now.

MKB: Okay, but is there something you can look at and say, "This is what people will get if they fund me?" Is there anything tangible?

AK: For my work specifically? Well, you never know where it will take you. There are some things you can foresee a little bit. But I’m hesitant to guess. You do get benefits from astrophysics, though. There’s the selfish curiosity of knowing, but in that process we create technologies to detect the light we're analyzing. And a lot of those will be practical in the future.

When you're using your digital camera today, you’re using technology that optical astronomy developed 30 years ago. Today it's in your camera. Lots of technologies from radio astronomy are in your cellphone today. You wouldn't have that without basic science trying to detect light at different wavelengths. You really have no idea where the technologies we develop today will take you in another 10, 20 or 30 years.

MKB: But why government funding? Why not find a private organization or corporation that wants to help you research space dust?

AK: I think there's many sides to this. Right now, private funding tends to be product based. It has to lead to a product within a few years for a private company to be interested. So it may be practical and possible for things with immediate applications, but it's hard for me to see why a corporation would be interested in something long term and uncertain.

Basic research used to be privately funded in the past, like with Bell Labs. That used to be THE place where basic research was happening. But somehow that model has disappeared and I think it's because corporations are looking for more short term goals. There's really no corporation doing basic research in the same way Bell Labs did.

But there are also reasons why you might not want it, even if they were interested. Corporations are interested in proprietary technologies and getting out ahead of another company. They won't share what you discovery and they'll use it exclusively to their advantage. They'll file patents and protect their turf. And that’s fine. But the reason we want public funding is that we want to generate public knowledge. We want to share this with the world. We want it to be immediately available to everyone around us. Science doesn’t have trade secrets. I think public funding is essential to keep it that way.

Main Image: Cosmic dust of the Andromeda Galaxy as revealed in infrared light by the Spitzer Space Telescope. Public domain, via Wikipedia.