A Close Call Collision In Near-Earth Orbit

IRA FLATOW: This Is Science Friday. I’m Ira Flatow. Later in the hour an update on the coronavirus and tackling invasive species in the Great Lakes. But first, Wednesday night sky watchers near Pittsburgh looked up watching just in case there was a collision in space. Joining me now to talk about that and other stories from the week in science is Amy Nordrum, who is editor at the IEEE Spectrum. It’s good to have you, Amy.

AMY NORDRUM: Thanks, Ira.

IRA FLATOW: What were they expecting to see when they were looking up there?

AMY NORDRUM: Well, it was a little tense that night. There were two defunct satellites no longer operational that were coming very close to each other as they orbited Earth. These satellites were alerted to the public by a company called LeoLabs, which track space junk that’s orbiting the Earth.

And LeoLabs put out an alert on Twitter that says, we’re expecting a pretty close call here. Keep out watch for that. So there are a lot of people that had kind of their eye on the sky that night, trying to see if it would actually happen. And fortunately it didn’t, because if these two satellites had collided it would have created a lot more space debris, which is a problem we don’t need to exaggerate.

IRA FLATOW: Yeah. Because we have enough of that up there, right?

AMY NORDRUM: Yeah. There’s many thousands of pieces. And if these satellites would have collided, it would have– all that debris would have kind of spread out into a huge belt that orbited the Earth for many years to come, complicating future launches. So we’re thankful that did not occur.

IRA FLATOW: I think they were expected to be pretty close, right?

AMY NORDRUM: Yeah. They think that they came within about 40 feet of each other. And I talked with Dan the CEO at LeoLabs, and he said these kinds of close calls are becoming more common as we put more stuff up there. He said his company is tracking so much junk that every week they see two large pieces of space junk that come within about 100 feet of each other.

IRA FLATOW: Wow. Wow. I’ve seen that movie where all that space debris goes crazy. OK. Let’s move on. There’s a story this week about Dungeness crabs and not a good story, right?

AMY NORDRUM: No, you know as we add more carbon dioxide into the atmosphere, we’re also adding it into the oceans, making the oceans more acidic than before. And we’re starting to see how this affects some of the creatures that live there, including Dungeness crabs, which live up and down the west coast of the United States.

A new study of the larva of these crabs shows that the shells of the crabs and parts of their bodies are dissolving due to the the increased acidity of the ocean. And they’re also seeing these effects on structures called mechanoreceptors, which are hair-like structures that these crabs use to find their way around.

IRA FLATOW: And that means that our Dungeness– San Francisco must be up in arms about stuff like this.

AMY NORDRUM: Yeah. And it’s not totally clear how this is affecting the crabs. It’s not clear if it’s slowing their development perhaps, or maybe making them more vulnerable to predators. But those are some hypotheses that the researchers leading this work are going to further investigate.

IRA FLATOW: Yeah. And it’s all– when we talk about climate change, people like to talk about global warming. But it’s more than just the warming. It’s also about the acidification of the oceans, right?

AMY NORDRUM: Yeah. One of the researchers I spoke with, she was saying this is kind of an early warning signal that this is a phenomenon definitely worth paying attention to with these crabs.

IRA FLATOW: Oh, goodness. The coral and then the crabs.

AMY NORDRUM: I know.

IRA FLATOW: OK. Let’s move on. We’ve talked in the past about the maybe miracle material graphene, one of my favorite subjects. Now there’s news about making it cheaply. Is that right?

AMY NORDRUM: Yeah. This is pretty cool. So graphene, just to review, is kind of a form of carbon in which the atoms are arranged in a single layer and packed together very tightly into like a hexagonal structure. It’s very strong. It’s extremely thin. And it’s an excellent conductor, which has made people very excited about using this material in lots of different purposes.

It was discovered way back in 2004 and it’s been really hard to produce large amounts of this stuff. It’s very expensive to do that. So now some chemists at Rice University have come up with a way that they think they can make graphene from essentially trash.

And they’re using a technique called flash heating, that basically using electricity to heat stuff up very quickly to extremely high temperatures. And they’re able to produce graphene from stuff you’d never believe, anything that contains carbon like rubber tires, plastic bottles, and plastic waste, even pieces of cabbage or coconut that contain carbon, they can make graphene out of that using this approach.

IRA FLATOW: Now they can make– I mean, they used to make graphene out of putting scotch tape on a pencil, right? On the lead in the pencil, and get one layer of carbon out of that.

AMY NORDRUM: Yeah. The trick is to be able to do it at scale. And to be able to produce the kind of graphene that’s useful. So there’s other ways to produce graphene that kind of make like a chunky version of graphene. But that’s hard to mix up. And this stuff, like if you wanted to use it for something like mixing into paint or mixing into asphalt, so this technique creates kind of single layers of graphene stacked on top of each other, which are a little bit easier to use for those purposes, they think.

IRA FLATOW: We don’t have any products, though from graphene.

AMY NORDRUM: Well, they’re starting to see some. So there actually are some Goodyear bike tires out now–

IRA FLATOW: Is that right?

AMY NORDRUM: –that are graphene enhanced. And there’s also been some experiments using graphene, mixing it into asphalt for stuff like runways on airports when heavy planes land, to try make those materials more durable. So you’re starting to see it come out, but the Rice University chemists think that this technique will make it a lot easier for people to use it in more products.

IRA FLATOW: All right. Now finally, you have a story about something I thought I would never talk about, which are sweaty robots.

AMY NORDRUM: Yes. You know, sweating is very useful. It helps keep us cool when we’re working out or on a hot day. And robots could use it too, because they have a lot of moving parts many times. There’s a lot of heavy processing going on.

You can just think of like when your laptop revs up and sounds like it’s going to take off. Overheating can be a problem for these robots. And this is especially true for soft robots. It’s hard to put fans into those soft robots and other cooling systems in something that has to be so flexible.

The researchers from Cornell University and Facebook have built a set of robotic fingers, used a 3D printer to make these hollow fingers that have pores on the back and you fill them with water, and the pores widen when the material heats up. So the water leaks out and evaporates off the surface of the robot fingers, cooling it down six times faster than fingers made that did not sweat.

IRA FLATOW: Do they have– well, if they sweat, do they have a way to drink and replenish?

AMY NORDRUM: That’s the part that they haven’t added yet, which is a limitation to this work, so–

IRA FLATOW: Oh, details, details.

AMY NORDRUM: Yeah. That’s probably the next step, is you have to be able to add more water in order to keep it sweating, as we all know.

IRA FLATOW: And we all, it’s because we all want to make them more human. Is that the point here? If you work out, you should be sweating.

AMY NORDRUM: Yeah. It’s like a more efficient way to cool. It’s more flexible. It’s not as– heavy fans, you know have to add those components in. So it could be a really good way to go. But it also complicates things. Like when you sweat, you get slippery. And these are robot fingers, and they are made to kind of grip things, so there’s other complications that may come with sweaty robots. But it’s a cool experiment to see.

IRA FLATOW: I can see the Gatorade commercials now.

AMY NORDRUM: There we go.

IRA FLATOW: Thank you much, Amy.

AMY NORDRUM: Thanks, Ira.

IRA FLATOW: Amy Nordrum, news editor at the IEEE Spectrum.

Copyright © 2020 Science Friday Initiative. All rights reserved. Science Friday transcripts are produced on a tight deadline by 3Play Media. Fidelity to the original aired/published audio or video file might vary, and text might be updated or amended in the future. For the authoritative record of Science Friday’s programming, please visit the original aired/published recording. For terms of use and more information, visit our policies pages at http://www.sciencefriday.com/about/policies/