Science Friday - Dung Microbes, Gun Research, Airplane Germs, Kepler Mission. March 23, 2018, Part 2

Episode Date: March 23, 2018

Guns kill more people in the United States than alcohol—from homicides and suicides, to mass shootings like the one that left dead 17 high school students in Parkland, Florida last month. But public health researchers will tell you that studying alcohol-related deaths is much easier. Gun research is so fraught politically that the Centers for Disease Control and Prevention doesn’t fund it (though the National Institutes of Health did for three years during the Obama presidency), and a pair of Congressional amendments continue to throw red tape on funding and access to certain kinds of data. Could private foundations, universities, and state governments fill the gap? Most zoo visitors go to see the animals. U.C. Santa Barbara chemical engineer Michelle O'Malley visits for their poop. That's because the dung of grazers like sheep, giraffes, and elephants is rich in cellulose-chomping fungi and bacteria. She joins Ira to talk about the bacterial and fungal communities within poop. When you fly on an airplane, you’re trapped inside a metal tube for a few hours with hundreds of other passengers, sharing the overhead compartments, lavatories, and air. It feels like there’s a good chance for disease to spread in flight—but just how likely is it? New research maps out the risks. Plus, NASA launched the Kepler space telescope in 2009, with plans for it to operate for about three and a half years. Now, nine years later, the telescope is close to running out of fuel.     Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Ira Flato. Later in the hour, we'll check in on the state of firearms research in the U.S. and we'll look back on NASA's planet hunting Kepler mission, soon coming to an end. But first, most people visit the zoo to see the animals, right? But my next guest visits for their poop. Now, before you get too gross doubt, you need to know that the dung of elephants and giraffes and sheep and other grazers is a veritable treasure trove for microbe hunters, full of hundred, bacteria and fungi involved in all sorts of complicated friendships or rivalries.

Some are even frenemies. And untangling all that could be key to better biotech, perhaps a way to unlock energy from corn stalks and grass clippings and agricultural waste or develop new drugs. Chemical engineer and Dung Detective Michelle O'Malley of UC Santa Barbara presented that work this week at a meeting of the American Chemical Society in New Orleans. She's here now to explain. Welcome to Science Friday. Thanks very much.

I just got to ask the question of, you know, what's so interesting about poop? Yeah, that's a question I get a lot. You know, poop has, for really everything, a mixture of microbes that help whatever, wherever the poop came from to degrade food material into products. And by looking at the poop of animals in this case, we get a clue on how those animals have unlocked the energy contained in fibrous plant biomass, which we typically think of as fiber that we couldn't get any sort of nutrition from. So animals can, and that's why we want to hunt into their poop to find these microbes and their enzymes. Give me an idea of how you actually hunt around. Do you follow the animals or what's the process like? Right. So in fact, it is better to have fresh samples. So when my research group goes to the local Santa Barbara Zoo to do this, we wait for the animals to donate, so to speak, to our cause. And then we scoop up just a tiny bit, take it back to the lab, and then where we coax out the microbes that are doing the degrading.

And your lab must be a kind of smelly place, I would imagine. fortunately these are anorobes meaning that these microbes we isolate don't want oxygen around that means that we can lock them up in in oxygen tight container or oxygen-free containers so we don't have to smell them which is good what are you actually looking for what would be the great find in the poop that you know right home about so the the principal thing we're after are enzymes which are proteins that do the action of taking plant matter and turning that into sugars that the animal derives nutrition from. So initially, we were looking for enzymes in these unusual organisms that nobody has really looked at before. And what do they tell you? And what do the enzymes do for you?

So the enzymes work together to perform the complex chemistry of breaking down a polymer called cellulose that is really just a network of sugars. And our bodies can't process cellulose because we don't have any of the enzymes to break it down into bite-sized pieces of sugar. And you said microbes can be frenemies, friends and enemies at the same time. How does that work? Right. So it turns out that the microbes that produce these enzymes, there's many different types of microbes, fungi, bacteria, and there's archaea in there, there's viruses, there's lots of things going on. And so it turns out that these microbes produce different flavors of enzymes, and they will change what they do depending on who they see.

So take, for example, anaerobic fungi are really good at making kind of the enzymes that enable access to other microbes, and bacteria will come in and swoop up those byproducts and then use another class of elements. enzymes to turn that into something else. And that means that there has to be a balance of the microbes in the microbiome or else one will take over. And so they have a way of talking to each other, benefiting from each other, but also keeping each other in check. So tell me the kinds of secrets that you can steal from these microbes as relates to biofuels or drugs or whatever you could learn from that. Right. So I'm a chemical engineer and that means that I want to harness the

the power of nature for producing useful products for humanity. And one way that we can do that is by, of course, learning from their enzymes and trying to produce those enzymes at scale. But another way that we could do that is by actually manufacturing with the microbes themselves. So trying to have bacteria and fungi working together in bioreactors to produce complex chemicals that not one of them could produce on their own. and those could be fuels or actually, if you can believe it, even antibiotics. Yeah, well, we know there are a lot of bacteria in the soil that produce antibiotics.

The problem is growing them in the laboratory because they don't like to come in from the cold. Right. That's exactly right. Something like 99% of microbes on Earth have not been cultured and cannot be cultured. Part of that is because they need to have their microbial community and their neighbors around in order to get all of the nutrients that they need to survive. and to actually grow in the lab. And that's part of what we're working on as well. Now, I know you've worked with some more exotic animals, like giraffes.

Do more exotic animals, you know, where I'm going with this, have more exotic gut microbes? Yeah, so it turns out that that is, in fact, true. We and others have studied wild herbivores, so to speak, that are out and really have to have to have scrappy microbiomes in order to live. and the more extreme, the location that you find the animal, generally the more diverse you find the microbial community that helps it to get energy. And so that is very much true. Do you ever play a little game with?

You show me the microbiome. I'll tell you what animal it came from. We haven't done that yet. That would be a really interesting thing to try in the lab for sure. Might the human gut have any microbes useful to biofuel production, drug developments? something along those lines? Why limit it to animals? Right. We work on animals as a starting point, but it's very true that the human gut microbiome, we're learning more and more about it, and there might also be similar types of chemicals that are made by microbes to keep each other in check

that could be harnessed as new drugs and antibiotics. So it's very much a potential. If you and your colleagues hang out so many times at the zoo around these animals, Does your microbiome pick up their microbiome? Aha. It's an interesting thing to consider. I think that we always become a reflection of our environment no matter where we go. Our microbiome is no different. Many of the microbes that we study from animals, chiefly anaerobic fungi, however, will not live in our digestive tract because it's simply too short for them.

so they can't hang on during the ride. The animals, digestive tract, in particular ruminant animals, have many compartments, and so they are able to harbor a diverse type of microbiome that we just can't help to survive. Tell me your dream, an animal poop that you'd love to get under your microscope, that you haven't had a chance yet to sample. Actually, so musk oxen that live in the extreme Arctic thrive on, really scarce plant material called lignacelose that, well, actually it's widely abundant, but they don't see it a lot.

And so they must have a really good microbiome. So when they happen upon that lignacelose, they get as much energy as they can from it. We would love to travel there and get some of those samples. The musk oxen. Mm-hmm. Yeah. So you haven't gotten them yet. Can somebody send you there?

If we put a shout out here, somebody to send you some, it has to be fresh poop that you're looking for them. Right. I would stop short of requesting that people send me poop to the lab. But certainly, if someone wants to fund us to send us there, that would be great. Is there any, I'm going to give you my blank check question. I do not have one with me, but just if I did, and you could create, you know, take it to create equipment or go someplace. What would you do? What would you do with it if you had unlimited sources of money?

What do you need to spend it on? Right. So we actually need to discover the little chemical linkages between all of the microbes. And those are things called metabolites. So this is what cells are making. And there's thousands, tens of thousands of tiny little chemicals that the cells make. And each one of them, even if they're there in low abundance, connect the microbial community. So we would love to measure all of those connection points in great detail.

in order to truly understand how microbes communicate in the gut microbiome. Do you consider microbes sort of almost like people? You talk about them. Yeah. Yeah. Of course. Microbes are in many ways like us. They have their friends.

They have their enemies. They have their frenemies. As we started out saying, microbes become specialized. And you can't teach anyone, microbe, to do everything that you'd like it to do in biotech. but by dividing and conquering, just like people do, it's a new route to making things that we can't make right now in terms of biofuels, bioproducts, and drugs. Do you think, now that you, because you go to the zoo for the sampling, and there's sort of, you know, a captive audience, so to speak, would the animals in the zoos have a different microbiome than the ones that might be in the wild, the same animals? Right. So we've noticed that that is, in fact, the case because the zoo animals don't have.

have the same stressors. They have a pretty regular diet. And some of them are actually constantly fed low levels of antibiotics just to keep them from infection. And so the microbiome that you see in zoo animals is often very different than what you see from wild animals. Does that hinder your work? I'm saying, you know, I'd rather have something out in the wild instead of in the zoo?

Right. So our goal is, as an engineering team, is really to try and develop the most hearty biotechnology. So that means that the cells that survive under the widest collection of conditions are the ones that we want. And so in that way, getting samples from the zoo animals helps us because we know that they're pretty hearty microbes and they'll grow under many different conditions. And so in our work, it actually helps us. All right. Fascinating work. Do you visit other zoos besides Santa Barber? We would like to.

We have some calls out to other zoos and other states that have different animals, for example. We haven't quite gotten there yet, but it would be great to do so. Okay, well, maybe you'll get a few calls after both people who will listen to this. I'll give you a call. Michelle O'Malley, Assistant Professor of Chemical Engineering at the University of California, Santa Barbara, UC Santa Barbara. Thank you for joining us. Thank you. Have a good weekend.

We're going to take a break, and when we come back, there are some, shall we say, hurdles to doing rigorous studies of gun violence in the United States. But what are scientists accomplishing in the meantime? What's on their wish list? Why can you learn from studying all these statistics? We'll talk about it after we get back. Stay with us. This is Science Friday.

I'm Ira Plato. It's been over a month since a shooter gunned down 17 people at Marjorie Stoneman Douglas High School in Parkland, Florida. And since then, survivors have done their best to reinvendivated. the national conversation about preventing gun violence of all kinds. They're calling for assault weapon bans, closing background check loopholes, and beyond. And they and their supporters are rallying in Washington this weekend in the March for Our Lives to make these demands hurt.

But if you're a public health researcher and you want to study gun violence, where it comes from, what interventions might actually work? Good luck getting funding. a 20-year-old Congressional Act, the Dickey Amendment, says of the funding given to the Centers for Disease Control and Prevention, none may be, quote, used to advocate or promote gun control. You can imagine how that political language has chilled firearms research. Well, fast forward to this week. Congressional Republicans this week are adding a clarification that the amendment does not actually prevent research, that clarification says. And on the other hand, a different amendment still limits access to the FBI's database of firearm purchases.

Now, wouldn't that data be useful? That doesn't mean no one's doing the research. Researchers with university funding, private foundations, even the Justice Department, they are turning out papers, and the states themselves are trying to bridge the gap. Last year, California established its own center for gun violence research with the University of California. New Jersey is considering a similar project that Rutgers, and even New York State might follow suit. So, what's next for firearms research?

What have we learned about stemming the death toll, and where are there still gaps? Let me introduce my guess. Garrett Wintamute is Director of the University of California Firearms Violence Research Center, Professor of Emergency Medicine at UC Davis. Welcome to Science Friday. Thanks for having me. You're welcome. Catherine Barber, researcher at Harvard's T.H. Chan School of Public Health,

Director of the Means Matters Program for Suicide Prevention. Thank you. Welcome to Science Friday. Thank you very much. Glad to be here. Garon, I just said that there are plenty of researchers turning out papers, but what do people mean when they say gun violence research is hard to do? Well, first off, there are way shy of plenty of researchers. The small size of the labor force is one of the larger problems we're dealing with. fundamentally, firearm violence is a health problem.

And to quote a prior director of CDC, if it weren't a health problem, why would all these people be dying from it? The point here being that it can be studied as any other health problem is. And for other health problems, we recognize that understanding the nature of the problem and how to intervene lies at the foundation of effective treatment and prevention efforts. We do that for motor vehicle injuries, opioid overdoses. We do it for heart disease and cancer. We need to do it for firearm violence. Now, the Dickey Amendment, and I'll quote from the amendment, it says no money can be used, quote, to advocate or promote gun control.

But this doesn't talk about, I would think in the pure state doing research about guns doesn't actually have to lead to gun control. It's just understanding how it's all working. So that's exactly right. And I'll say that some of the work that we do makes gun control people quite angry because we follow the data. But to the Dickey Amendment, people in the field have understood since the 90s that at least in the language, there never was, there is not today a ban on research. So fast forwarding to the events of the last 24 hours, all that has happened, as you pointed out in your setup for this segment is a clarification of that. Nothing new has happened. So the research community doesn't see a significant change in the events of the last 24 hours. If there were funding, if there were even encouragement, that would be something else again. So you were saying, as you mentioned before, that it would be helpful to research guns in the same way we research public health problems like drug overdoses or car crash just because so many people die?

Yes, exactly. Yeah, Catherine, one of the areas of gun research that's still happening despite the obstacles is your project means matter. What we know that two-thirds of gun-related fatalities are from suicide, that's more than 20,000 people every year. Tell us what you're learning about preventing those. Well, it's true that about 60% of firearm deaths are suicides. That statistic, in some regards, conceals more than it reveals. because there's a tale of two very different populations in the United States. Among white people, among white Americans, 83% of firearm deaths are suicides.

Among black Americans, 84% of firearm deaths are homicides. And so it becomes very important to look at the specific local circumstances, the local data, to see what can be done in the white community around suicide and particularly in certain black communities around homicide, and to be detailed in those investigations and to involve, particularly on a suicide issue, to involve gun owners in that conversation. And so what does your project Means Matter do to help what you're looking for? Well, 10 years ago, the suicide prevention movement wasn't talking about guns, and gun owner groups weren't talking about suicide. It simply wasn't on the radar. For the suicide prevention groups, they were well aware that gun access was a risk factor for suicide, but they felt it was too controversial to talk about guns because they had a very narrow perception that talking about guns meant taking a stand on gun control, when instead there are, there are, there. There's a tremendous scope for common ground for non-legislative solutions to the issue of firearm access and suicide.

So what strikes me about this project is that nothing you're talking about requires any actual legal change in the regulation of guns, just a cultural shift. There's a huge need for a cultural shift in the same sense that 30 years ago nobody had heard about designated driver or friends don't let friends. drives drunk, that's taking that same approach to guns and suicide so that if a friend or a family member is really struggling with a depression or a drug problem, and especially if some other crisis is overlaid on that, like a horrible divorce, your third drunk driving arrest or something, that's the time to say, hey, I'd feel a lot safer if I could hold on to your guns for you, or if that's not legal in your state. what do you think about putting your guns in storage just for now until the worst of this blows over?

It's a nice bro way of showing you care, and it also substantially improves their safety. Well, that brings me to that question. Do you know that it actually works? Does it substantially improve their safety? Well, the way that we got to this was by looking at their – about 16 case control studies in the United States looking at risk factors for suicide and looking at whether gun access is a risk factor, and in fact it is. And we looked at data to figure out, well, is that because of the nature of the person,

the community, or the gun itself? And so I asked Ron Kessler to add to the National Comorbidity Survey a question about gun ownership, and it's a survey that screens for mental health problems. We saw that gun owners were no more likely to be suicidal or to have a mental health problem. So what it is, is in the event that they become suicidal, they're just more likely to die in a suicide attempt. So it seemed like, well, that means we need to get word to gun owners and their families.

And do you send into the gay and lesbian community to do, to do suicide prevention group work. Would you send an anti-gay group? Probably not. So who are the right messengers for this message for the gun-owning community? Well, probably you're going to trust the messenger when it's a firearm instructor, when it's a gun shop owner, when it's a lecture at the spaghetti dinner at the sportsman club. Very interesting.

Garron, what are some of the other research projects that are turned? turning out interesting results. Give us an idea. Sure. I'll mention as a bridge an intervention that's called the gun violence restraining order, which is actually quite similar to what Kathy's been describing. In a situation where risk is high and imminent and firearms are involved, there are currently five states. We in California are one of them that allow, as with domestic violence, allow members of the family or law enforcement to go to a judge and make the case that the firearms ought to be taken out of the situation. We are evaluating the program in California.

I don't have aggregate data, but at the anecdotal level, I'm aware that this process has been effective. There has been a rigorous quantitative evaluation done in Connecticut, which also shows that there's been good effect. On your broader question, we know that identifying and prohibiting firearm purchases by people who are at high risk, and federal law and state statutes have varying definitions for who should not be allowed to purchase a firearm. We know that those sorts of restrictions work.

We actually did a prospective controlled study here in California of a policy. that prohibits people who've been convicted of violent misdemeanor crimes from buying guns. It's a myth that people who've been convicted of violent crimes can't legally buy guns. And in most of the country, they can buy as many guns as they want, as long as those crimes aren't felonies. California changed its policy, and we found that that change in policy reduced risk of future violence among the people who were affected by 25 to 30%, which is a big effect.

So if the state of California is having its own fling at gun research now, and I don't mean that derogatorily, if enough states step up in the same way, you know, because that's what states seem to be doing now in many different aspects of social caring, can they make up for a lack of the federal involvement? I mean, can you all pool your data without having a centralized federal agency doing it? No, not a chance. The data collected at individual state levels differ quite a bit. So pooling would not be an effective approach.

But there's a larger point to make here. There is a level of research that, at least traditionally, has only been feasible with federal support, whether it comes from CDC or from NIH, which also for a few years was funding research in this field, but has since essentially stopped or from NIH. I'm talking about the large projects that sometimes address the most important questions, questions that can't be addressed on a small scale, projects that might cost several million dollars to complete. Without that level of support, those questions simply will not be answered,

and I don't think it's realistic to expect individual states to pony up that kind of money. Tell me about the questions. that need to be answered, that are not being answered. So I will give you as an example, one that is being answered, we're answering it, that couldn't be answered on a small scale. The question is this. Among people who legally purchase firearms are those who, at the time of purchase, have a documented history of alcohol abuse, repeated DUI convictions, et cetera,

at greater risk down the road for violent crime. Preliminary data suggests that they are, and that would comport entirely with what we know about alcohol and violence. But in order to answer the question definitively, the study has to be large enough. It has to involve tens of thousands of people who are followed over time to see, based on their prior criminal record and other characteristics, what their risk for outcome events is. And we are doing that study here in California with support from NIH. And, Catherine, does gun suicide have any connection with domestic violence shootings or mass shootings? Well, certainly there's a great deal of overlap when it comes to the issue of murder suicide.

when a man kills his current or former intimate partner in over half of those cases, he also kills himself. Even though murder suicide is a very rare event when it comes to intimate partner violence perpetrated by a male, it becomes more the norm than not. So voluntary steps among family members and friends to look out for their loved ones when they're going through a difficult crisis that may lead to either suicide or homicide to say, hey, you'd be safer with the guns out of the house for now. This is Science Friday from PRI Public Radio International. It's like you say, friends don't let friends drive drunk, take the keys away, drive somebody home. You're saying you need the same kind of friendship going on. Yeah.

And in terms of the research, what's been so fascinating for the kind of work that I've been doing in New Hampshire with the New Hampshire Firearm Safety Coalition and in Utah with a similar group is bringing gun owners and people care a lot about. outgone rights into the process of developing the research questions and thinking through the data. It's fascinating to learn to respect one another's opinions and to really challenge one another's, the kind of blinders that we all have. I only have a couple of minutes left. I want to get two more questions. What kind of data do you need? Garren and also, Catherine, what data is missing?

Gary, you gave me one answer, Catherine, what data do you need? Data at the state and sub-state level on gun ownership and gun storage and on perceptions of risk. We need data on how guns very specifically are moving from the legitimate to the illegitimate markets and how they are moving from legitimate use to illegitimate use. Do you think anything is going to change, Gary? Yes. I think very concretely and in a short period of time, we are likely to see gun violence or straining order statutes adopted at the state level. The available data suggests that they work had such a policy been in place in Florida and used. It might well have prevented the Parkland shooting, and that's a matter of general knowledge. Now, Florida has since adopted a gun violence or straining order statute.

the National Rifle Association has come out in favor of them, and I suspect we will see that movement pretty quickly. Okay, that's all the time we have. Next week, our story is going to continue with efforts at tackling urban gun homicides and new research and how social networks and social media might help us predict and even intervene before violence happens. Karen Went to Mute, Director of University of California Firearms Violence Research Center, at UC Davis, Catherine Barber, at Harvard's T.H. Chan School of Public Health Director of the Means Matters Program for Suicide Prevention. Thank you both for taking time to be with us today. A quick break, and when we come back, just what are the odds of getting sick on that cross-country airplane flight? We'll talk about it after this break. Stay with us.

This is Science Friday. I'm Ira Flato. When you take an airplane flight, you're trapped inside that metal tube for a few hours with, what, perhaps hundreds of other passengers. You're sharing the overhead compartments, the laboratories, the air. It feels like there's a good chance for disease to spread in flight, right? Somebody's coughing here. Somebody's sneezing over there. But just how likely is it? And research published this week in the proceedings of the National Academy of Sciences, Vicki Stover-Herzberg and her colleagues tried to actually map out how respiratory viruses like the flu might spread during air travel. This is how they did it. Members of the research team took 10 flights across the U.S., and they recorded the behavior of the passengers as they moved about the cabin.

Who got up during the flight? How long they lingered outside the restroom, how the passengers interacted with each other and with the in-flight crew. And Dickey Stover-Herzberg joins us now to talk about what they found. She's professor and director of the Center for Data Science at Emory University in Atlanta. Welcome to the program. Thanks, Ira. You know, I have to plead guilty of this because there's a common perception, oh, I had a fly, now I'm going to get sick. That the airplane is just a flying petri dish full of, you know, stuff.

Is that true? Well, that's certainly something that you hear a lot, and the question is, is that true or is that recall bias? And the answer is? Well, we don't know because we really don't. There's no organization that's keeping statistics on who's getting sick on airplanes outside of a few reported events. There's maybe, I don't know, 18, 20-something things that have appeared in the literature over the years. But you actually went on the planes and looked at the risk of flu transmission during a cross-country flight. What did you find?

Well, we found that for people that were seated in either in, one row in front of, one row behind, or two seats to either side of an infectious individual, that those people were the most likely to become infected. And that the people that were seated outside of that perimeter of risk is what I call it, were unlikely to become sick. How did you actually physically determine that? Well, we assumed a certain risk of infection that we got from a study of passengers on a plane that was grounded on a tarmac in Alaska for something like four and a half hours. No air circulation.

And so we calculated a risk rate from that from that, from the, from, that report and applied it to the duration of one meter contacts that the passengers on our flights had. So what about the airline crew? How do they fit in? Well, they, if there is an infectious passenger, they are less likely than the people that are seated immediately around that person to get sick, but they're more likely than, people that are distal to that passenger. You know, we always talk about that germs are transmitted by touching things, right? You're going to get it on your hands.

Did you find that there was residues of germs on the doorknobs or the latches in the plane? We took air samples, and we also swabbed surfaces. So we swabbed tray tables. We swabbed seatbelt buckles. and we swabbed inside and outside lavatory doors around their handles. And we tested those swabs against, and the air samples, against a panel of 18 common respiratory infections. There was something like 229, I think, samples that we considered, and all of those were negative for every one of those 18 common respiratory infections. respiratory infections.

Wow. But we did not specifically look at how people were touching things. So we've still got a ways to go to get a better understanding of how the touch might play a role in disease transmission. One of the things that we travel is very fearful on airplanes is that the air itself is just getting recirculated with all the germs in it to everybody. What did you find there? Again, we found nothing. Those samples were all negative for the common respiratory viruses that we were assessing for in our panel of 18. And also, in modern aircraft, they are becoming increasingly better about their air circulation.

And it's changed actually much more frequently now than your average officer. office building. So you're probably, your office building is less clean than the air in the airplane. I wouldn't say that, but I would say that the airplane is being presioned more often than your office building. And what's next for you? Have you got some more research in progress? There are some things that we'd like to do, look at exactly how people are touching surfaces, Look at double-isle aircraft, look at what's happening in the gatehouse area, look at aerosol exposures. That's another thing. While we consider were things that, you know, almost the things that you can almost see when somebody coughs or sneezes.

And those things fall right down to the ground. And that's why being within a meter is so important. in risk. But we don't know about things that the finer particles that stay suspended in the air and move about the cabin. And also you have the whole waiting area, too. Yeah, yeah, there's the waiting area. And so we want to do that.

We're just waiting for somebody to shower us with money to do that. Well, throw a little our way, okay, if you get showered. I certainly would. Okay. Thank you, Vicki. Vicki Stover, Hertzberg, is Professor and Director of the Center for Data Science at the Neil Hodgson Woodruff School of Nursing at Emory University in Atlanta. Thanks for talking with me today and have a good weekend.

Thank you, Ira, for your interest in fly healthy. Bye-bye. NASA launched the Kepler Space Telescope in 2009, and it was supposed to operate for, what, about three and a half years. Well, it's kept running for over nine years, and during that time has spotted over 24. 500 confirmed exoplanets. But now its end is in sight.

I'm sorry to say that. Joining me now is Geert Bairtson, a astrophysicist and director of the Kepler K2 guest observer program at NASA Ames Research Center in Mountain View, California. Welcome to Science Friday. Thank you, Ira. We're sorry to hear. Why is Kepler coming to an end? Well, you know, Kepler is now 94 million miles away from Earth.

And, you know, just like would happen on a long road trip. our fuel is running low. And of course, there are no gas stations in space. But we're not actually sad at all because Kepler has been taking so much data. It's this gold mine of data, and actually we think it's going to take another decade to sift through all the data.

Wow. So for those of us who may have forgotten, what is Kepler's mission? Well, Kepler was NASA's first exoplanet mission. And what that means is it took the first census of planets outside our own solar system. So Kepler is a telescope.

And what it does is it's like a big bucket of light. And it is looking at stars measuring their brightness. And what it's looking for is like minute dips in the brightness of stars. Because when a planet moves in front of its star, we can record this by looking at the brightness carefully. And when this dip happens periodically, we know that a planet must be orbiting that star. Quite interesting. A few years ago, I remember parts of the telescope were failing, but you kept it going. How did that happen?

That's right. So Kepler uses spinning wheels called gyroscopes, which keeps its gaze stable. It needs a really accurate pointing to keep the stars very, very centered on the detectors. Now, two of those wheels failed a few years ago, but our incredible engineers actually came up with this fantastic solution.

They were able to point the solar panels of the spacecrafts to the sun in such a way that the spacecraft could be maintained stable using the pressure of sunlight, which, by the way, is an insane idea, and it worked. Don't you love it when that works? You know, NASA has some of the best engineers, and it's such a privilege to work with them as a scientist.

Well, all right, give us a highlight. Now, you've got your coat of chrome slides out on the screen here. Give us a highlight of your most favorite discoveries and the biggest contributions that Kepler has made so far. Well, you know, the big contribution is really discovering that planets, rocky planets, are called. We found more than 2,600 planets. I know you said 2,500 in the introduction,

but actually it's now 2,600, just because in the last month we found another 100. Oh my goodness. And you know, it's an incredibly diverse universe out there. We found hot lava planets. We found cold, icy planets. We found rocky earths and large super earths and fluffy mini-Neptunes and are sorts of crazy things.

And perhaps the discoveries I'm most excited about right now are things we've just been seeing in the last month, such as supernova explosions. Hmm. And you have citizen scientist planet hunters going through the data, helping you out, to sift through all that data? You know, Kepler looked at more than half a million stars now. So this is, you know, what many people might not appreciate is that ultimately the discoveries

from Kepler are made by humans on Earth and not by the spacecraft itself. But it's so much data that astronomers have been overwhelmed. So one thing with it is we put, like, all these data, public and we went one step beyond, we made easy interfaces and tools for people to sift through the data. And just back in January, we announced a planet system with five planets. And it was actually first discovered by a car mechanic in Australia who doesn't have a degree in astronomy, but he likes the night sky and he found this system. You've got to be very patient. You do have to be patient. But, you know, the reward is big, right? Because Kepler is really putting our own planet and our species

into context. What's the closest planet to us that might have some sort of life on it? Kepler may have found. You know, the closest planet we know today is a planet around the nearest known star, which is Proxima Centauri. Now, Kepler did not find that planet. Kepler did find a planet just in September called Gleza 9-827. You know, we like long, boring numbers. And that one is just 100 light years away. And the reason that's interesting is because the Hubble Space Telescope right now is looking at this object this year, and the future James Webb Space Telescope will be studying the atmospheres of the planets in that system more carefully in the future. I think it's really interesting how you're able to get to smaller and smaller planets to see them.

Absolutely. And, you know, in some sense, Kepler is only like a strategic cock in the wheel of NASA's long-term objective to answer the big question, which is, are we alone? You know, that's a question, which is perhaps one of the most fundamental questions our species can ask. And in the coming years, we're going to see more missions come online, which will help us answer that question. In fact, NASA is launching a new mission called TESS next month, which is going to help. I'll talk about that right here after I tell everybody that this is Science Friday from PRI, Public Radio International. Talking with the Geert Berenson, Director of the Kepler K-2 Guests Observer Program. All right, let's talk about tests.

It's scheduled to be launched. What did you say next month? Is it? How does it differ from Kepler? So Tess is an acronym. It stands for the transiting exoplanet survey satellite. And it is going to look for planets in pretty much the same way as Kepler did. Except now that we know that planets are obliquitous, you know, we think there might be trillions in the galaxy, Tess is going to focus on finding the planets that are around the most nearby and brightest stars in the sky. And astronomers love bright stars because we can spend.

the light of bright stars into colors using advanced instruments called spectrographs. And when we do this, in those colors, we can see the chemical fingerprints of atoms and molecules, which help us understand exactly what these planets and their atmospheres are made of. How is Tess going to be different from the upcoming Web Space Telescope? So Tess is really about finding the planets. Tess is an array of small telescopes, and it will find the planets which then James Webb and other instruments will follow up.

Wow. How do you go about finding? How do you know where to point? Is there a sweet spot in the sky, or do you just, and how much of the sky can you take in at any one time? Well, so this is the key difference between Kepler and Tess. Kepler was a statistical mission. It asked how common are planets? And the answer was very common. But it only looked at a small patch of sky where it could do a large number of stars. Now Tess, in some sense, is doing the opposite. It will perhaps look at less stars, but it will do all the bright nearby stars across the entire sky,

which is why its telescopes are smaller, but the planets it finds are more amenable to be studied using James Webb. That means you're going to need a lot more people looking at what's going. You know, all the data we collect, both Kepler and Tess, is public, almost straight away. And I'm very proud it's the case because we need people's help. How do you get involved if I wanted to become part of that, you know, as a citizen scientist? So there are a number of websites people can go to. If you look for Kepler citizen science on the Internet, you will find a few projects called citizen science projects, which often provide an easy interface to look at the data.

Now, people who want to go a step beyond can go and look for our software tools and our tutorials. That's just one thing I personally work on here at NASA, is we make tutorials which help both scientists and the public work with the data. Wow. So are people getting misty-eyed now that Kepler? I mean, I remember when Cassini, a different type of spacecraft. People were really upset, visibly upset. What about Kepler? You know, we are proud.

Because, as you said, Kepler was designed to operate for about three and a half, four years. We are now nine years past launch, and this is beyond anyone's expectations. Also, it is still operating. It is still collecting data, and it is really a gold mine of data, which is going to take a decade to fully sift through. And even though Kepler might retire, all the astronomers on the ground will not. They will be working hard for the next 10 years on the data. Well, I wish you good luck, and we'll be following you. What's the launch date?

What's the window? Right now, it is due to launch on April 16, it is on schedule. Protest, T-E-S-S standing for? Transiting Exoplanet survey satellite. Wow. Okay, well, you promise to come back and talk about it a little bit when it's up there? That would be a privilege.

Oh, we would love to have you back. We've run out of time now. Gert Berensen is an Astrophys assistant director of the Kepler K-2 guest observer program at NASA Ames Research Center in Mountain View, California. Have a good weekend. Thank you. BJ Leiderman composed our theme music, and we have helped today all the time from all the people who work for us. And if you missed any part of our program, I'd like to hear it again.

Subscribe to our podcast. If you have a smart speaker, yeah, you can now ask it to play Science Friday whenever you want. Every day now is Science Friday. Also, we're on Facebook and Twitter and Instagram. You want to email us turning into that old-fashioned emailed way of community? kidding at SciFry at ScienceFriaday.com and send feedback and tell us, tell us what you'd like to hear from us, what subjects you'd like to hear us cover. Have a great weekend. I'm Ira Plato in New York.