Can space dust help cool Earth? A San Antonio astronomer is looking into it

Angela Speck, chair of astronomy and physics at UTSA, researches the dust and its potential applications for climate change.

By Michael MarksJune 6, 2022 10:02 am,

Astronomers are often concerned with things that are massive, rather than minuscule. But Angela Speck is an exception.

Speck, a professor and chair of the physics and astronomy department at the University of Texas–San Antonio, studies space dust – tiny particles from broken down cosmic bodies that drift through space.

Speck spoke with Texas Standard about her research, and whether the dust could be a tool to lower the planet’s temperature. Listen to the interview above or read the transcript below.

This transcript has been edited lightly for clarity:

Texas Standard: Before we get into some of your research, can you help us better understand what space dust is exactly?

Angela Speck: It’s very small particles of either something kind of like soot or something like sand – but like really fine talcum powder and dispersed in the universe. So it’s really spread out. It’s not like clumps, like you would get on a beach.

Is it a consistent substance? if you saw it in one part of the galaxy, you’d see it elsewhere – made up of the same elements?

One of the things that I study is how it changes as you look in different places. So in some places it will be sooty, in other places it will be like sand. And in some places it’s just weird. So it varies hugely. And that’s from the point of view of both what it’s made of and its crystal structure. If you think about soot, it’s actually made of tiny particles, some of like graphite – so black – and some of like diamonds and they’re very different in how they behave.

So how does all of this relate to climate change?

One of the ideas that’s out there for how to mitigate climate change is that we can put a layer of dust up into the upper atmosphere. Actually, this happens on a semi-regular basis when there’s a big volcanic eruption that throws dust up into the stratosphere. So for those people old enough to remember the Mount Pinatubo eruption in 1991, you could actually see its effect on global temperatures. The temperatures are increasing steadily on the hockey stick graph, but then you have this little tick downwards at the end of 1991, beginning of 92. And that’s because so much dust was put into the stratosphere by that volcano, that it reflected more light. And so the light from the sun didn’t get to the ground. And so it sort.

So it sort of serves as an insulator or a kind of blanket of dust particles that that that effectively insulate from rising temperatures, I guess.

Exactly. Those of us that are old enough to remember the 80s will remember the idea of a nuclear winter. Now, that’s taking it to an extreme where you’ve got so much dust up there that you don’t see the sun. It’s like foggy. And then you get so little light coming through that it gets really cold. And this idea has also been used in fiction. There’s a movie and a series called “Snowpiercer,’ where the premise is somebody took this idea of change, fixing climate change by putting dust up into the atmosphere, and it went too far and now the earth is too cold.

I think a lot of people worry that you start to tinker with these major systems that are part of our atmospheric environment. And the possibilities could be both beneficial and perhaps nightmarish. Can you describe a practical application of the sort of research that you’re working on? How do you envision it?

I think that, like with a lot of basic science, we do science to understand how things work. We may not have a practical application. So fixing climate change, I agree, we don’t want to just throw a bunch of dust up there because it might be catastrophic. But with what I do, we can actually test some of those ideas about what happens with how dust is interacting with light, and so how it’s affecting energy flow. And so we can really determine, is this a good idea? What should be made of, what size should the particles be and do that without having to be catastrophic on Earth before, before we put it up there?

How far off might that determination be? Are we talking about in maybe five years,  people like you doing this sort of research will be able to say, ‘this actually is not just science fiction here.’

I think there’s a lot of people already looking at this. I think one of the things that we’re lacking is the lab data. And that’s part of what I work on is developing new materials and then determining what they look like. Because there’s some stuff out in space that’s not natural on earth. And it may be one of those things that works best. And I would say probably five to 10 years is a reasonable estimate.

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