After 7 Years, NASA Gets Its Asteroid Sample

DESSA: About a week ago, space nerds got the care package of a lifetime– a sample from Bennu, an asteroid currently around 200 million miles from Earth. This mission, called OSIRIS-REx, marks the first time the US has collected a sample from an asteroid and then safely brought that precious cargo back down to Earth. Scientists hope that it will unveil some of the mysteries of our universe, like how the sun and planets came to exist and even how life began.

Here, with more science news of the week, is Sophie Bushwick, technology editor at Scientific American, based in New York.

Sophie, welcome back to Science Friday.

SOPHIE BUSHWICK: Thanks for having me.

DESSA: OK. So Sophie, help me calibrate my enthusiasm. How stoked should I be?

SOPHIE BUSHWICK: Super stoked. This is just like incredibly awesome because Bennu is 4.5 billion years old. It dates back to the beginning of the solar system. So by harvesting a sample from it, researchers can learn a ton about the early days of the solar system. And also, because it contains a lot of carbon-based compounds, it can give us clues about the origins of life. So very, very exciting stuff.

DESSA: OK. Can you walk me through some of the logistics? How did they get it? And then the challenge of returning to Earth with it was particularly onerous, right? How did that all happen?

SOPHIE BUSHWICK: So this is a multiyear mission. It launched in 2016, and it took two years for OSIRIS-REx to just get to Bennu. Then it spent another two years mapping it and figuring out where it was going to take this sample from. It finally takes the sample, and then it hangs out for a few more months before heading back to Earth– another long trip back here. And then it had to release what’s called the sample return capsule. This is a very specialized case for the sample. And it has to be specialized because it has to survive reentry through Earth’s atmosphere. It gets to Earth. It releases a parachute so it can land safely.

And then teams of researchers had to go out and retrieve it. It landed in Utah. And then they partially unpack it, but they mostly get it ready for transit to Texas, where it’s taken to this facility where it can be unpacked more fully because you don’t want Earth’s terrestrial atmosphere touching this thing. And just getting this sophisticated case open, it takes hours and hours because they’re not just opening it up, they’re also like, oh, did any scraps of Bennu dirt get stuck in the head of a screw? We want to harvest that dirt. That’s a valuable sample.

OSIRIS-REx ended up grabbing a sample that they think was about 150 to 350 grams. This is maybe a 1/3 to 3/4 of a pound of material. That doesn’t sound like a lot, but that’s more than they initially were hoping to get. The target was just 60 grams. So they’ve gone over and above that.

DESSA: I had no idea it was that small. That’s like me buying Brussels sprouts. I don’t even like Brussels sprouts.

[LAUGHTER]

SOPHIE BUSHWICK: Yeah, but these are like alien Brussels sprouts from outer space.

DESSA: OK. Other cool space news this week. I know that there was a big story about antimatter and gravity. But first off, can we just set the table– remind us what is antimatter and where do we go to get some?

SOPHIE BUSHWICK: So antimatter is– essentially, it’s sort of like the fundamental particles that make up matter, but with opposite charges. So an antimatter version of an electron is called a positron. An antimatter version of a proton is just called an antiproton. And if you take an antiproton and a positron and put them together, you end up with an antihydrogen atom.

So antimatter, you can’t go find it. You would have to either go back to the Big Bang, which is not a trip we’re equipped to make right now, or you have to go to a particle collider and smash a bunch of things together to make and then harvest your positrons and your antiprotons.

DESSA: And I know that the new finding now really dealt with the way that antimatter responds to gravity. Can you explain that?

SOPHIE BUSHWICK: Right. So scientists know that Einstein’s theories are still very good at predicting how gravity works, but it breaks down when you get into the realm of very, very tiny objects, where quantum mechanics hold sway. Then you start having some issues. So in order to understand this better at that tiny realm, researchers want to not just make theoretical calculations, but also to do experiments to see if those calculations hold up.

And one of the things that they theorized was that antimatter atoms would behave the same way that regular atoms do in response to gravity. If you put antihydrogens in a gravitational field, they’ll fall down, the same thing as if you put regular atoms into a gravity field. But the question is, can we prove that this will actually happen?

DESSA: And so was this study important– or was this finding important– because it’s part of a proof of concept that it’s validating the theorists’ ideas about how antimatter would react to gravity?

SOPHIE BUSHWICK: Yes, exactly. First, they had to make some antimatter atoms. And then they put it in the tube and they measured, are they going to fall to the bottom of the tube or are they going to float up to the top of the tube? And the amount that fell at the bottom was roughly what they would have predicted from regular atoms– from normal matter atoms. So that suggests that antimatter and regular matter behave the same way. But that was under these specific conditions.

So now the researchers want to go back to this experimental setup and try changing some aspects of it. What happens if you change the temperature? How does the behavior change then? So this is just the beginning of a testing process.

DESSA: What does this fundamentally reveal to us about the way that the universe works? How does this fit into our understanding of the cosmos?

SOPHIE BUSHWICK: So one of the big antimatter questions is, why don’t we have it? So according to theories, when the Big Bang happens, it really should have made equal amounts of matter and antimatter. But fast forward to today, and clearly that’s not the universe we’re living in. So what happened there? Why don’t we have this antimatter version?

So when an antimatter particle meets its equivalent matter particle, the two will annihilate– they destroy each other. You take an electron and a positron and tell them to make friends, and they’ll go boom.

So if we had equal amounts of matter and antimatter at the beginning of the universe, maybe some of these particles were annihilating each other. But there was maybe more matter, and that’s why we ended up with the matter-based universe today.

But researchers are still trying to study this in any way they can. And this experiment is just one part of that.

DESSA: OK. So zooming the camera in from the entire expanse of outer space to the tip of a pin, I know that there’s been some really exciting news in vaccines this week, particularly for the respiratory syncytial virus, a.k.a. RSV. Can you tell us, what is RSV and what’s new about this vaccine?

SOPHIE BUSHWICK: Yeah. So RSV is a disease that’s not going to be very harmful to you if you’re a healthy adult, but it can be very dangerous for young children and babies and for the elderly. So there was actually a surge of it last year. And in severe cases, it can cause pneumonia. It can land kids in the intensive care unit. So it’s a really scary illness in that aspect, and so there has been more attention put to it.

And so now we finally have a vaccine against it. And this vaccine is specifically– it’s not designed for children. It’s designed for pregnant people. And the idea is that this immunity is passed in utero to the child.

DESSA: OK, got it. So this is specifically designed for pregnant people to take. Then it sounds like some of the antibodies in this vaccine cross that placental barrier and actually protect the kids after birth, is that right?

SOPHIE BUSHWICK: That’s right. And this is a technique that’s been known for a really long time. And there are other vaccines that pregnant people are encouraged to get in order to convey that immunity, but this is the first vaccine that’s designed to do that from the beginning.

DESSA: OK. Hard pivot, Sophie. Streetlights– I think this was my favorite story of the week. Apparently, LED streetlights are turning purple around the world.

SOPHIE BUSHWICK: Yes.

DESSA: Tell me why.

SOPHIE BUSHWICK: So this is not a Halloween prank. This is happening because of the way that we get white LEDs. So if you want to make an LED, you don’t make a white LED. You could take a combination of different colors that would give you white. Or you can take a blue LED and coat it with this fluorescent material called phosphor. So when the blue light hit the phosphor, the phosphor releases some red and yellow colors, and the combination of all of these gives you your white light.

But the problem is, what happens if that phosphor layer peels off? That could be due to an issue with the manufacturing of the LED. It might be about exposure to heat. But what actually happens is the layer peels off and that blue light underneath is free to get out and it looks purple.

DESSA: To my eye, I think the purple looks really pretty. But I know that there’s also some concerns about safety. Are there hazards associated with these lights aging into a purple hue?

SOPHIE BUSHWICK: Yes, this is an issue if you want to be driving at night. So if it’s dark out, the part of your eyes that’s able to process this bluish light, it tends to be your peripheral vision. It could cause issues because your forward vision would be not as good under this purple light as it would be under white light. And so there’s the potential safety issue– like, maybe it’s harder to see pedestrians and maybe drivers are more likely to make errors.

DESSA: All right. Let’s end where all good stories do– with beetles. Sophie, there is a new study out about beetle diversity that is super counterintuitive. Tell me.

SOPHIE BUSHWICK: So beetles are just this weirdly diverse group. So we know that there’s about 1.5 million species known to science. And this is not just animals– This is plants, this is microbes– 1.5 million species. Of that, about a quarter of those species are just beetles.

DESSA: What?

SOPHIE BUSHWICK: It’s wild. So the question is, why are beetles so diverse? Why is this particular group doing this and branching out so much? So there’s a couple of ideas. One is that they’ve got these external wings that protect their flight wings that can let them live in a lot more environments. And if you’ve got them branching off into different environments, they could specialize in those environments and diversify.

Another possibility is that a lot of these beetles eat plants. So maybe each one could have evolved to munch on a specific different species of plant. But the problem with both of these theories is there’s this one family of beetles, called rove beetles, that– they’re very diverse– but they don’t have really highly developed external wings and they don’t even eat plants. So why did the rove beetles get so diverse? That’s what this new study wanted to find out.

DESSA: Oh, I feel like a special shout out at this point in our show to the 1/4 of our listeners who are likely beetles and listeners.

[LAUGHTER]

OK. So we’ve talked about the external wings. We’ve talked about plant eating. There was also a potential chemical defense against ants. Is that right?

SOPHIE BUSHWICK: That’s right. So ants are this big predator in the insect world. They’ve killed off a lot of species. And in the case of the beetles, these rove beetles developed a chemical defense gland that they could spray at ants. And the idea is maybe they got so diverse because each of them developed a different flavor of chemical that was good at targeting a different kind of ant.

DESSA: It’s so rad. It’s so cool. Sophie, thank you so much for joining me.

SOPHIE BUSHWICK: Thanks for having me.

DESSA: Sophie Bushwick is technology editor at Scientific American. She’s based in New York City.

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