Scoping Out the Universe

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Looking back in time

0:44Using even a small telescope on a clear night, we can see thousands of stars. But in addition to admiring the beauty of the Milky Way, we are looking back in time. So by looking at those stars and looking at the distribution of planets around them, we can basically see the past and the present and the future of our solar system. Now, a group of amateur stargazers has helped confirm some important discoveries. Welcome to Big Picture Science. I'm Seth Shostak. I'm Molly Bentley. In this episode, we look at the first images coming from the Vera Rubin Observatory,

1:19hear about collaborative research between citizen scientists and professional astronomers, and examine strange energy bursts originating in a seemingly quiet part of the cosmos. We are Scoping Out the Universe.

1:46Let's talk for a moment about what we're looking at when we peer into the night sky. If we use a large telescope, we can see light coming from stars and galaxies that are both far away and far back in time. Some of that light may have taken so long to reach us that the objects from which it comes may have died long ago. We see them in their relative youth. And it's also true that even though light travels fast, there are things far enough away that we haven't seen them at all yet. One of the things that's always to wrap your head around with astronomy,

2:16the scale of what that means in distances is, quite frankly, mind-boggling. Despite the challenges that great distances present to astronomers, we've become quite adept at interpreting light reaching us from long ago. Astronomers can study objects and make a kind of historical record of the cosmos. Telescopes, the instruments used to collect that light, are sometimes called light buckets. Even Galileo's simple backyard telescope gathered enough light to reveal new facts about the Milky Way.

2:48Today we have telescopes that can show us far more distant objects and a cosmos that the Italian astronomer never could have seen. But it isn't just the stars we're interested in. It's also the planets that orbit them. If the planet is far away, you can use this technology so you can see the planet, see the planet moving around the star. And when you see something, it's more interesting because you can start having an idea of the temperature, the composition, and maybe some variation of light, suggesting, for instance, the presence of atmospheric activity.

3:22Of course, it's tantalizing to think that some of these planets might be habitable, and that possibility has encouraged both amateur and professional astronomers to spend hours at their scopes. But some telescopes, including radio telescopes, are presenting other cosmic mysteries lurking in the farthest depths of the universe. For about the last 20 years, there's been these signals that astronomers have no idea what is causing them. With every observation, new questions seem to emerge.

Images from Vera Rubin

3:50So let's begin with the big picture from the Vera Rubin Observatory in Chile, the first observatory named after a woman. Construction of this instrument began over a decade ago, and now the telescope is producing images that some say are unparalleled in detail and depth. Astronomer Claire Higgs describes one of the dazzling images, the cosmic treasure chest, a stunning panorama of objects from bright stars to spiral galaxies to distant galaxy groups. Reuben is able to scan the sky very quickly and very deeply,

4:26and taking these huge images at once. So if we talk about the cosmic treasure chest image, so that's the image of part of the Virgo cluster of galaxies, when we start looking at what's in there, it's really covering a huge range of science. So let's start far away. So in the background of that image, you see a whole ton of little red galaxies. Those are very high redshift galaxies. Then if you come a little bit closer, you're seeing the Virgo cluster, and those beautiful spiral galaxies that are those Virgo cluster. And then if we come a little closer,

4:57we start seeing stars in our own Milky Way, like the variable RR Lyrae stars. You see the variability in their brightness. Those are all in our Milky Way. And if we take one step even closer, we start seeing asteroids in our solar system. So being able to cover this huge range of sciences all together in one data set is what Reuben is going to do over the entire southern sky. And this one image just is a sneak peek of what Reuben will do. Claire, could you say a little bit more about that capability of the Virgo-Rubin Observatory

5:28and how it compares with the Hubble Space Telescope? Because the Hubble, too, has been celebrated for its deep field images. So what capabilities of Reuben make the images different or distinct from those produced by Hubble? So the important thing to remember about the Reuben Observatory is that we're designed to be a survey telescope. We are not designed to look at one patch of the sky or look at one particular type of object in great detail.

6:00We're designed to look at the entirety of the southern sky. And the way Reuben works is that about every three to four nights, we will have scanned the entire southern sky. And then we do it again and we do it again and we do it again for a decade. And that allows you to see things that move, change, and blink. So think asteroids and supernovas. And it also allows you to see really deep. If we take all these images together and we stack them together, you are able to see those really, really deep images. So Hubble is a space-based telescope. It has a small field of view,

6:30but it takes these, you know, exquisitely detailed images. You can see all this amazing structure over a very small area. Reuben is designed to take very big images that are also deep, but we're ground-based. So the resolution is a little bit different. You have to look through the atmosphere. Hubble has the advantage of being above the atmosphere. But our ability to look at the sky that fast and that often allows us to create a data set that is unique. And so one of the things that, when you think of that image of Virgo,

7:01by creating that image that quickly, you can actually see the asteroids moving in that image, which is something that Hubble, Hubble was never designed to do and Hubble can't do. It's capturing a dynamic universe. Yeah, it will be the greatest cosmic movie ever made because instead of what we see as this static night sky, in reality, there's lots of things that are changing and blinking and moving. And we don't typically capture all of those. So, Claire, although you said that the Vera Rubin Observatory

7:32is not designed to look at specific images in the way that Hubble was, for example, it has produced some pretty stunning singular images. And one of them is of two nebulae, Trifa and Lagoon, I believe. It may have been dubbed, or one of them has been dubbed the Cotton Candy Nebula, which gives you an idea of what it looks like. It's this light pink. But could you describe for us what the image is? Mm-hmm. So this image produced by the Rubin Observatory shows the Trifa Nebula and the Lagoon Nebula together

8:05and the kind of landscape between them. And you're right, it looks like cotton candy. You see all these kind of swirls and pinks and blues. But what you're looking at is a stellar nursery where young stars are being born. And in environments like this, where you have a lot of star formation and young stars, it's a very energetic place. And so those stars are releasing winds that are carving out the gas and dust around them, creating these spectacular shapes and energizing particles. And so you see this really beautiful reflection

8:39and nebula around these two. Seeing them together in this kind of cohesive landscape and all of the structure that's surrounding them is really unique to Rubin. And the fact that this image was produced really quickly, it took about 650 images combined. So that's about 2 trillion pixels of data to create this image. That only took a couple of nights for Rubin, which is really amazing. Is it unusual to see two nebulae so close together?

9:09Are they drawn together by the forces of their movement? Or is that unusual or something that's actually quite common? Well, that's an interesting thing, that the fact these two nebulae look like they're close together, but they're not actually. So Triffid is about 5,000 light years away and Lagoon is about 4,000 light years away. So in projected distance, they're about 1,000 light years away. So although we see them close together in this image, when we think of them in three-dimensional space, they're actually not neighbors. It's funny, isn't it? It's hard to get our minds around

9:39the distances involved in these images. Yes, I think that's one of the things that's always to wrap your head around with astronomy is trying to understand those distances and the fact that, you know, when I talked briefly about that image in Virgo and the fact that you're seeing things in our solar system and then in our galaxy and then in the Virgo cluster and then at High Red Ship, the scale of what that means in distances is quite frankly mind-boggling. I'm wondering what the wavelengths are that Vera Rubin is viewing these images with

10:13and then what that allows it to capture that maybe another telescope wouldn't be able to capture. Yeah. So Rubin observes the sky in six filters. So we have U, G, R, I, Z, and Y. So this goes from the near infrared through the optical wavelengths to the near ultraviolet. And having the ability to observe the same object in different wavelengths allows us to understand what we're looking at. So for instance, a galaxy that is forming stars

10:43tends to emote more light in bluer, shorter wavelengths, whereas older stellar populations, so a galaxy that formed stars a long time ago, tends to emit light more in kind of redder wavelengths.

Filters and wavelengths

10:56And it's just a reminder that the principal function of telescopes is to collect light. So telescopes are light buckets. That's what they're sometimes called. Now, light comes in many different wavelengths. Only a narrow band of the electromagnetic spectrum is the light that we can see, the so-called visible light spectrum. But different spectral regions give you different information, right, Claire, about what it is that you're observing. And what I actually think about is the fact that we can use pairs of wavelengths

11:28to tell us a lot. And so some observatories will use spectra. So you take the light from an observatory and you split it into its range of wavelengths. That's not how Rubin works. We simply use our six filters to break it into kind of six wide chunks of wavelength. But by comparing those to each other and understanding how an object appears in all six of those wavelengths allows us to understand something about what that source is, perhaps what elements are part of it. We talk about metallicity of an object.

12:00So that is basically how many elements that aren't hydrogen and helium are, you know, part of that object. And so starting to piece together all the information that we see in those different wavelengths gives us deeper understanding of every object. Well, Claire, could you remind us what the insights were that astronomer Vera Rubin had about how galaxies move and specifically how spiral galaxies move, for which she did not win, but many thought she should have won a Nobel Prize. So Vera Rubin was a truly amazing astronomer

12:34who found the first compelling evidence that there perhaps is something else out there in the universe, which we now call dark matter. And so her studies looked at the rotation of spiral galaxies. So she looked at these beautiful spiral galaxies and saw how they were moving and how they were rotating. And she found that if you look at their speed and how they were rotating, it implied that there has to be more matter.

13:05There has to be more stuff in that galaxy than what you could account for by looking at the stars and gas and dust that you actually see. And didn't it have to do because the outer edges of the spiral galaxy were moving faster than would be predicted by the mass of the galaxy if you did not account for dark matter? Yeah, that's exactly right. So you simply saw the rotation curve, basically. How fast the galaxy was rotating as a function of its radius was going too fast in those outskirts

13:35to account for that matter that if you just added up the mass that you could see from the stars and gas and dust. And it wasn't a small finding because from there, the theories were developed that most of the universe is made up of this dark matter, this unknown stuff, as opposed to dark energy, which seems to be blowing the universe apart. Dark matter is the stuff that seems to be holding it together. Exactly.

Dark matter and galaxies

14:02So Claire, some astronomers, you could characterize them as almost giddy with how Vera Rubin Observatory, how they think the Vera Rubin Observatory might transform our view of the solar system. This is where we live. This is our cosmic backyard. How might these images and the study of those data captured in those images actually change how we think about or understand our solar system? Or maybe what are some of the big questions that might answer?

14:32And I know I'm asking you about the unknowns, but do you have any idea of where this might go? Well, I think it's going to be fascinating, and I'm sitting on the edge of my seat to see kind of what happens. But I think that we have a lot of ways of exploring the questions of dark matter and dark energy, and Rubin will play a huge part, the Rubin Observatory, because we're never going to play a huge part of that. But hopefully we'll understand it a little bit more fully and completely. And one of the things

15:02that I think is incredible is the Rubin Observatory is going to start its survey later this year and do a survey for about a decade. But after that, the discovery won't stop. This data set that we're creating will be something that is foundational and informative and rich for so many years to come. And there'll be so much to understand in there. Plus, we have other amazing observatories around the world and in space that can follow up on some of the things that the Rubin Observatory

15:34might catch the first of or an interesting glimpse into. And then we have other observatories to continue that science as well and more deeply as a huge global collaboration. It's going to be very exciting. Well, Claire Higgs, thank you so much for describing some of the tools that are helping us understand our place in the universe. We really appreciate it. It's great to chat. It's very exciting times. Astronomer Claire Higgs works with the public outreach team for the Vera Rubin Observatory. Coming up,

16:14we shift our attention from professional to amateur astronomers and the role they play in helping to confirm new observations. This episode of Big Picture Science is scoping out the universe. This episode is brought to you by Indeed. You're ready to level up your business, but the pressure to find the right person to make that happen is intense. Indeed Sponsored Jobs

16:44can help carry the load. It boosts your job post to help it reach quality talent fast. Cut through the chaos with Indeed Sponsored Jobs. Get a $75 sponsored job credit at indeed.com slash podcast. Terms and conditions apply. Hiring now? Then this is a job for Indeed Sponsored Jobs.

Discovering exoplanets with TESS

17:13We've long been fascinated by the possibility of worlds beyond our own. Now we know they exist. We've discovered thousands of extrasolar planets or exoplanets as they're called planets that orbit other stars. We're interested in them because in addition to being astronomically intriguing, they may be habitable and even support life. Since the discovery of the first exoplanet, astronomers have learned that there are more planets than stars in the universe.

17:44Also, that planets similar in size to the Earth are not uncommon. A frequently used scheme for discovering exoplanets is the so-called transit method. It involves pointing our telescopes at stars and seeing them slightly dim as a planet crosses in front of them. So, Seth, when an extrasolar planet crosses in front of its sun, what does the dimming of the light tell you about that planet? What it really tells you is the size of that planet, of course, first and foremost. And if you see it repeatedly

18:15occulting its home star, then you get the period of its orbit. And that's, you know, important in determining some of the astronomical circumstances of that planet. Well, NASA has a space-based telescope that is devoted to detecting exoplanets using this transiting method. It's called the Transiting Exoplanet Survey Satellite, or TESS. So, TESS is a NASA mission that observes the sky, a large part of the sky, continuously for a specific amount of time,

18:45and then analyze the brightness of stars in this part of the sky. And by comparing the brightness of the stars, we can detect some small attenuation of light. TESS is dedicated to search for exoplanets. The bigger is the exoplanet, the more attenuation you see. The further is the exoplanet, the longer the transit, this attenuation will last. So that's the way we find most of the exoplanet at the moment,

Amateur astronomers confirm a planet

19:12by using this kind of instrument. But sometimes even professional astronomers need a little help. Recently, that help came in the form of a global citizen science network of amateur astronomers using small digital telescopes from the company Unisteller. One of the co-founders of Unisteller, which collaborates with the SETI Institute, and SETI is the Search for Extraterrestrial Intelligence, on citizen science projects, told producer Brian Edwards that amateur astronomers were able to help confirm

19:42the existence of the gas giant exoplanet with the name TOI4465b, located approximately 400 light-years from Earth. Hi, my name is Frank Marchese. I'm an astronomer at the SETI Institute, director of citizen science, chief science officer at Unisteller, and chief executive officer at SkyMapper. Frank, so we just finished hearing from Claire Higgs at Vera Rubin, and Molly talked with her

20:13about the literally massive images that the observatory is compiling of the night sky. And we brought you on to talk telescopes as well, but we're hoping, you know, we can talk a little bit more specifically about a certain object, that being the exoplanet, I believe it's TOI4465b, a very compelling name. Can you tell us specifically why it's so interesting to astronomers? So TOI4465b was discovered

20:43in 2022 using the TESS mission. TESS is a NASA mission, which basically look at the stars, a bunch of stars, and detect a small attenuation of light of the star, indicating the presence of a planet in orbit around the star. So we don't see the planet, we see the shadow of the planet. And when this was discovered, the transit, which is the duration of this attenuation, lasted for like 12 hours. So astronomers got very interested

21:15because if the transit lasts for such a large amount of time, it suggests that the planet has a very long period, meaning it could be something like Jupiter, far away from the star. So what we do in this case is to call for observations, for additional observations, to confirm this planet candidate as a planet and nail down its period and its orbit. And I think you hit on an important word here, it's confirmation. And that's kind of part of the process

21:45of when we're finding indication of this planet, but we still need to confirm it afterwards. That's correct, right? Yeah, that's correct. So what astronomers will do, we first detect a signal, say, oh, that could be a planet. Then we call for additional observation coming from different type of telescopes. So in this case, we did radial velocity measurements. So we detect the variation of the speed of the star that is due to the rotation

22:16of the planet. And from this, those astronomers infer that there will be another transit happening in 2020 to August 8, to be exact, plus or minus 24 hours. It's important that you catch it in that window to be able to make that confirmation. So you kind of miss your chance until it comes around again. Exactly. If you miss it this time, you will have to wait 100 more days to do it again. And it's,

22:46I mean, we're observing from the ground. So we are limited by the duration of a night on one site. So it can be eight hours, plus or minus two, typically close to the equator. Plus there is the weather issue. It can be cloudy at this time. So that's the reason we are using this network of telescopes to do this kind of observation. From my understanding, there were 24 amateurs in 10 different countries who helped make this confirmation. And I think that's, personally at least, it's quite cool that amateurs

23:16are able to contribute in this way. So can we dive into, you know, what is this network? What were these amateur astronomers helping do to confirm this planet? So we have thousands of candidates, test candidates. What we do, we choose the one at the SETI Institute that could be confirmed by this network. And then we make a call for confirmation. So we warn our network. We have 3,000 potential observers at the moment. And for this one, we managed to mobilize

23:4724 of them. And they observe roughly 230 hours continuously, this star, to detect this attenuation of light, suggesting the presence of this exoplanet. So essentially, the advantage to having these amateur astronomers and using these unicellar telescopes to help out is you're able to avoid some of those issues, like you said, like cloud cover, like weather or things like that, because you can essentially observe

24:17from several different points on the Earth. Yeah, we have collected observations from people from all around the world. They're very powerful, they're digital telescopes. So we're entering in a new era in astronomy called digital astronomy. So this isn't the first time that we've had amateur astronomers make observations, make discoveries, but you describe this as a new era of amateur astronomy. So what makes this particular confirmation notable? So the reason

24:48we say that we're entering in a new era in astronomy is because of the technology. The fact that we can detect an exoplanet using a small telescope that you can carry in a tiny backpack, we're talking about something which weighs 10 pounds, something like that, right? And you deploy that and you get it ready in two minutes and you have a computer on board that calculates for you where to point and does everything and a super sensitive sensor that can basically observe the star. It's remarkable.

25:18It's basically computer combined with optics and sensors that make possible for us to build such a telescope. But it's something that is not, it's not been possible 20 years ago. It's now we can do this. So we had, you know, believed that this planet was there, but these amateur astronomers were able to help confirm it. What was the information that we needed or that was missing that they helped contribute? So what we didn't know

25:48is the orbit, specifically the period. We knew the transit will happen in a period of three days and it will last 12 hours if it was truly an exoplanet, but we didn't know exactly when. Now we have, because we have another detection of a transit, a clear estimate of the period of rotation of this planet around its star, which is 102 days or something like this. So now we know this is a warm Jupiter. So you have, you know, I think you said these 3,000 people

26:20who are able to help out with their smart telescopes. How do you communicate with these people? Is there a big email that you're sending out to everybody to kind of say point your telescopes here tonight? How do you organize this group of people to help with these observations? So we used to do it by email, but then we quickly realized that it will not be a durable. So now we have a Slack channel and we also have a website where people can see how to observe and what targets are observable from their location. And this one, TOI4465B,

26:52was definitely an interesting target because we were suspecting it was a Jupiter, a warm Jupiter. So we have diagrams showing where it's located, what people can expect to see, and then people start engaging with us and say, hey, we would like to observe it. And it's extremely easy. You simply go to our website, you enter your location and you can see which planet is observable and when. You can put that in your calendar and one hour before the observation, you could be warned, hey, you said you wanted to observe this exoplanet.

27:23This is the time. You put your telescope outside and you press one button to align the telescope, one button to start the acquisition, and then you can stay in front of the telescope and wait for several hours or you can trust the technology and go do something else. You were able to confirm it and what is the importance of confirming an exoplanet like this?

Why Jupiter matters for life

27:46There is multiple reasons, but one of them is because we believe that the presence of a Jupiter exoplanet, it's important for the formation of life on terrestrial planets. There is multiple scenarios that shows that if you don't have Jupiter or Saturn, you will not have liquid water on Earth. So, some astronomers believe that if you want to find life in terrestrial exoplanets, you need to find a system

28:17with a Jupiter, Saturn exoplanet. And there is not that many of them known so far. We know a lot of very nearby exoplanets like hot Jupiter that orbit on their planet in a few days, but we don't know those which orbit around the planet in 100, 200, 1,000 days. So, we are starting observing those and building a catalog of those exoplanets. So, to figure out those questions that we still have about the planet, what makes up its atmosphere, whether it's habitable, things like that,

28:48this is a time that we're then turning it over to the professionals, correct? These amateurs were able to help confirm its existence and now we need some professionals to step in and figure out the rest. Yeah, because if you want to confirm the composition, you need to be able to see the planet and have some information about the temperature, the chemistry, which can be extremely complex in the upper atmosphere of this planet. So, we need a large telescope for that. The universe is huge, so you need to have

29:18a lot of eyes looking at the sky. I think that hits on the last question that I have for you, Frank, and we have professional astronomers like you and those at the Vera Rubin Observatory that we talked to among many others, and you're all scanning the skies, looking at these different planets, stars, everything, but why is it important to also have amateurs and lay people who are at telescopes too, looking up at the sky? Because we will not be able to build

29:48enough telescopes to observe everything happening in the sky. Even though we have a lot of telescopes right now in Chile, in Hawaii, in South Africa, in Australia, if it's cloudy in one of these places, for instance, you suddenly don't have any way to observe the sky with those large telescopes. And that's key to understand transient phenomena such as a nova, supernova. That's key to do long-duration science like we have in this case,

30:19the observation of a transit that lasted more than 12 hours. So there is this aspect, which is a scientific aspect of it, but there is also the outreach part and the fact that we want people to connect to the cosmos. One of the reasons we created Unistella in 2017 was to build a telescope that will give access to the sky to everybody on this planet. And one of the reasons we believe it's important is because with lights in the urban cities

30:50right now, you can't see any stars. You look at the sky from Washington, D.C., from Paris, you will see maybe five or six stars in the sky. I do remember growing up in the suburbs where we could still see the Milky Way and it was not such a long time ago. So, bringing telescopes to people and allowing them to observe the dark sky again will reconnect humanity to space. I would think it's pretty cool to say that I helped confirm the existence of a planet that's hundreds of light years away. That's exactly the kind of comments

31:21I get on the Slack. But knowing that with a small telescope in your backyard in the middle of San Francisco, you have been able to confirm the existence of an exoplanet, I mean, who doesn't want to do that? It feels like if you get people bragging about the astronomy that they're doing, you're probably doing something right. Yeah. Well, Frank, thank you so much for taking the time to speak with us today. Thank you for having me. Frank Marchese is an astronomer and director of citizen science at the SETI Institute and the chief science officer of Unistellar

31:52as well as the chief executive officer at SkyMapper. So, Seth, Frank mentioned the important role that a Jupiter-like planet