ITU Tech Monthly | Radio Astronomy Explained: What Radio Waves Reveal About the Universe

Most people never think about radio spectrum, yet it's behind countless everyday activities. Every time you make a mobile phone call, connect to Wi-Fi, check a weather forecast based on satellite observations, you're relying on access to radio spectrum, that invisible natural resource that makes wireless communication possible. Scientists also rely on radio spectrum to study space. Long before we had satellites, mobile networks, or Wi-Fi, radio waves were already traveling across space. I'm very pleased to tell you that today's guest is letting us in on what these radio waves can tell us about the universe. Welcome back to another episode of ITU Tech Monthly, a snapshot go-to podcast focusing on the latest insights and innovations in the world of technology brought to you by ITU, the United Nations Agency for Digital Technologies. I'm your host Max Jacobson Gonzalez and today we're looking at a new series of articles recently published in ITU news focusing on radioastronomy and I'm very pleased to be joined by Dr. Julia IG Josher who is a scientist at the Maxplank Institute for radioastronomy and an expert in spectrum management and the protection of radioastronomy frequencies no less. and he coordinated this series of articles and together we will look at what these stories tell us about the future of radio communication. Dr. Julia, welcome to the podcast. >> Thank you for having me. >> Now, first of all, for our audience who may be hearing about it for the first time, what exactly is radioastronomy and what can it tell us that other forms of astronomy can't? >> Well, to to answer that maybe uh let's start with astronomy itself. So astronomy is a discipline of physics in which celestial objects including the cosmos as a whole are used as laboratories for physical experiments. Well, this is as any physics to verify and to adjust fundamental physical theories and scenarios of cosmic evolution. There is now an advantage and a disadvantage. Well, the obvious disadvantage is that we cannot influence the experiment. On Earth, we can shift our experiment. We can do something about it, but no one has reached the next star yet except perhaps the sun. We need to let it happen. The advantage, however, is that by observing these distant objects, physics can be tested under extreme conditions, never be reachable on Earth. The best vacuum can be found between the stars and the densest objects like neutron stars or black holes where physics even breaks down uh can only be found in astronomy. The largest distances and that's probably the most important are in space. You cannot have a distance larger than earth on earth. The most energetic particles are in space much more energetic than anything that we can produce in in on earth. Well, in Geneva for example, there's a very strong uh particle accelerator but uh the the particles in space are much stronger, much much more energetic. >> CERN in fact yeah you're referring to >> exactly without astronomy physics is incomplete. We need it. Radio astronomy is now a part of that that that complex is it's astronomy based on observations of cosmic objects in the radio regime with dedicated radio tools. Yeah. And those are just uh very sensitive receiver systems most sensitive receiver systems. You cannot buy them in a shop or something with high directivity antennas. 100 meter mirror of my home telescope for example. that gives you quite some gain. And with those we basically observe very faint radio noise generated in celestial objects and well we're also listening to uh to potential signals from ET in space >> as in the film >> contact. >> Exactly. Contact precisely written by an adviser to the NASA space missions as well, wasn't it? >> Yeah. Yeah, I think so. But uh yeah, it's it's probably going to be a little bit different. But I mean, we can we can talk about that later if if you like. Uh why I think contact will be a a very delayed one. It's basically physics. Anyway, >> just coming back to the second part of the question, what can radioastronomy tell us that other forms of astronomy cannot? >> Well, we see that some cosmic objects substantially change their appearance when looked at in in the radio light. So there a few blog articles discuss examples like a huge radio jets coming from super massive black holes ejected from super massive black holes. These are relativistic charged particles in in magnetic fields. They're larger than galaxies by far or can reach sizes larger than galaxies and they are mostly seen as a radio regime. the black hole uh the shadow of a black hole that that was was an image that that went around the world. You cannot see in the optical there is the neutral hydrogen neutral famous neutral hydrogen line at 1420 MHz uh which is well which shows the neutral component or neutral phase of the most abundant element in the world. Pulsars is an is a different example. So these are neutron stars uh which rotate very fast with a with a magnetic field. So they send pulses. They are perfect plots and you can do tests of general relativity and uh try to observe gravitational waves on a statistical basis. So another example, yeah, extraterrestrial intelligence. I've seen you you probably will only detect this in in in the radio. cosmic microwave background basically is a proof that the universe is or that there was a big bang that that that you can only see in the radio. So that that's in the that peaks around uh 100 gigahertz I believe depending on how you measure this. So uh some discoveries can only be made in the in the radio regime and uh in general no cosmic phenomenon can be understood without observing it at many wavelengths. So radio is indispensable in this picture. >> Indeed. Well, let's talk about right now why this series of articles and why now. World radio communication conference WRC27 is going to be coming up in in Shanghai next year. So what was the motivation behind the series and what you hope readers will take away from it? >> The WRC 27 in Shanghai. There are actually two agenda items expressively dedicated to radio astronomy. It's 116 and uh 118. And the last radio astronomy agenda item was in 2012. So it is basically important to remind the public and spectrum sector about the worth and the needs of radio astronomy especially in that context. So why why do we need radio astronomy and and what does it give us? But uh but it goes even further than that. And uh I I would say I I don't exaggerate when I say that we are at a crossroads for radio astronomy. Apart from the generally increasing pressure on the spectrum IMT um a new issue has basically emerged. You will find that in nearly every blog article of the series the increasing number of satellites and the push for satellite service is mentioned as a challenge. the the background is the following. Article 29 of the radio regulation sets the scene for a wise use of the spectrum in the context of radio astronomy services. In a nutshell, it would mean that or it says there are not many big radio telescopes and local arrangements can be made to enable their successful operations through national or multilateral spe special protection. So this enables then radio observances to obser to operate in a radio quiet environment. Um also in in bands that are not allocated to the the radio astronomy service it's it's required because uh modern radio telescopes since long have the capacity to observe very wideband and that's a requirement to do modern research. So one could say that this kind of usage is also stipulated in article 29 and article 1112 under which radio astronomy stations may be registered at any operating frequency. I remember in two in the year 2000 when astronomers spent two years approximately two years to find the best sites and then satellites happened >> right >> the ska um and and this is basically the the the topic the overarching topic that that we are that we're now witnessing or seeing >> because I mean essentially I was asking what common themes emerge in this series of articles and and the the particular challenges or trends that you will shape the future of radio communication over the next decade. You mentioned satellites here. Um are there any more? >> Yeah, absolutely. It's mostly it's it's mostly the the the satellite topic. Uh so how do we how do we arrange how can we coordinate satellite services especially direct to cell uh applications direct to device applications with other services and astronomy is is one of the most most uh impacted in that. So all the all the satellite topics they are they are concerning us concerning astronomers um as a whole especially of course on the 13th on uh directto device uh communications in IMT bands. So that they are up there they are there where astronomers are looking and there is nothing that attenuates the signal from those objects. uh and that leads to a very very strong potential for for interference to astronomy starts. So that the old arrangement doesn't work anymore. That's the problem. >> And and spectrum is is an invisible resource that affects everything from from mobile connectivity to GPS to weather forecasting and scientific research we talking about. Why should people outside the radio communication community pay attention to spectrum? Why should they be considering it and thinking about it? It's an invisible resource. Basically, most people are are pretty much unaware of it. I was just want to say what the what's the overarching uh reason that you think that people should be thinking about it. Is it a finite resource? Is it something that uh basically is going to be overpop populated and we're going to run into all sorts of issues in the future? Are there other reasons that people should be concerned about spectrum? >> Yeah, of course. I mean uh it is a finite resource and uh well maybe astronomy is is really a good example for that. It affects everyday life. So uh one example is uh the possible degradation of some applications like geodetic astronomy. This will have a direct impact because uh it it it affects our navigation and post positioning system using using in our cell phones. uh then of course there is a huge technological and scientific development that would we would withhold from coming generations. So my grandmother she she when when when when she was born general relativity didn't exist and general did relativity depends a lot or it was invented because there were some problems with the movement of some stars some some planets around sun. So Mercury had a had a strange movement. That was one of the motivations and then so general relativity happened. We can maybe safely say that without astronomy it would have been delayed at least to say the least by a few by a few years if not decades. And now for modern life you cannot live without without general relativity. Yeah. So again it's satellite navigation that depends on the the the different time time delay uh that that the a signal um gets in the gravity field of our earth there there is correction that needs to be done if that doesn't work positioning doesn't work perfectly right so um imagine we I mean I cannot I cannot look into the future but extra from that we are withholding if we if we really impact science too much we are withholding uh future technologies future um exploration from from our children and well grandchildren certainly >> you wetted our appetite before you talked about ET you talked about listening out for communications from outer space and then we mentioned the film contact that was written by a famous astronomer Carl Sean, but it was a fictional work. You said that it would be a long time before we might receive any signals from space if if ever perhaps. Who knows? I just really wanted to just dig a little deeper in there and ask you why you felt it would be a long time and do you think that there may be a possibility that we will hear signals at some stage from another life source from somewhere else? Yeah, we're we're searching for for life um unintelligent life or life in general. >> I was going to say not quite as we know it necessarily. Yeah. >> Yeah. Yeah. Yeah. Yeah. Of course. I mean that's a I mean uh Boris Soken in his his article he mentions uh the ocean ocean in in Solaris which is a wonderful novel by the way to saydeed. It was really great to see that. Ah, sorry. I'm I'm uh I'm I'm getting distracted. Well, anyway, what what we're searching is for aromatic um substances in other planets. That's number one. Number two, then there is city, the search for extraterrestrial intelligence. Um that is uh really searching for signals. These would be short pulses. there are some characteristics uh basically for RFI from from other civilizations and yeah if we wouldn't think that this would be possible then we wouldn't do it of course so there might be a signal and now comes the boring part so we get a signal let's say it's from Proxima Centuri which is four light years away four light years means that light travels and any radiation of course travels four years from here to there >> in other words. If we receive a signal and we reply to that signal, that would mean that we would wait 8 years for for the answer. So it would be uh we better we better think well about what we send up there once we have discovered and this is basically the closest stellar system. So yeah, there it would be of course a great discovery and uh and and this is why why we're doing it. We we we really want to know whether we are alone in space. But uh let's say communication that requires a different physics that than we know right now. So something something has to overcome this this this barrier of the light speed. Who knows? Um there is no indication that there is there that there is the possibility but we have believed in many types of physics. >> Will AI help us in this direction? >> Oh yeah. Uh you need to sort uh the signals. So there there's a vast amount of of signals of different shapes and also RFI from Earth uh entering those uh those antennas. Um and uh only with the help of uh really high performance computing and pattern recognition you can sort out possible signals that can then be examined further. >> Artificial intelligence will help us in terms of deciphering the the exploration information that you're receiving but not won't necessarily speed up uh the time that it takes to receive that information. I mean uh first uh the signal has to be recorded then you have tons and tons of data uh that you need to see through. Yeah. Something that a human being would never do. So in in that sense uh there is an acceleration but um not in terms of uh getting that information. We need to wait for the for the wow to signal. >> Exactly. Now, you've worked closely with experts across a wide range of topics. I wanted to ask you, was there a particular article or insight that changed the way that you think about spectrum management or revealed a challenge that isn't widely understood? >> The impact that can that direct to cell operation can have on astronomy. So any study that that astronomers or that that that were done based on the parameters provided in in study group 4 or working 34C indicates that there is a huge exceedence of protection criteria in astronomy bands. So in on on a scale that that that even sporious emissions uh will or may may impact astronomy uh in in bands far away that that could be allocated. So that's that's number one the astronomy topic discussions. So how seriously is astronomy taken basically I mean this this is this is what we are also testing right now. So how well is the message received that we need and coming generations need astronomy then of course the the lunar discussion. >> Yes I was going to ask you about that. Yeah, >> that is that is the last resort basically still for for for the moment and of course if we send up uh any any astronomy stations radio astronomy station is there there is a is a is a wonderful environment astronomy wise of course there's no atmosphere which means that we can get to frequency ranges that that were never explorable from earth >> from earth. Mhm. Well, the beginning of that is being discussed right now under agenda item 11.15 where lunar communications are discussed. It is also a question of starting with this astronomy needs this these communications of course. So we we need to make it work but we also need to take care that the the interference into astronomy in the shielded zone of the moon. So the the far side of the moon shielded from from emissions from from the earth. uh that astronomy there is protected. It's it's it's by the way uh the only radio quite zone at the moment mentioned in the radio regulations. >> Right. Interesting. And and of course that would require a great deal of investment as well as well as protection. >> Yeah, of course. I mean this this needs to be done carefully. Can we assume that that the far side of the moon would serve for for a number of experiments? So I I guess the space sector will also want to make it work >> to to get a get a get good environment there. Some measures of coordination are are easy separation distance. The moon is much more curved than the earth. So that's >> right. >> That's a good thing uh to shield for shielding. Quite a bit of effort would be needed in order to keep that protection up. If you compare that then to the effort that's required to bring an to bring a radio telescope on the moon that then you can't do it that there is no other way. So you have to have these special conditions in order to make it worth the the while >> and and you need astronomers to be there around the clock I I would imagine or could you do it all remotely? >> Hopefully not. I wouldn't want to be >> you don't know about um no I I guess I mean those things are those those observatories will be uh >> operated remotely we're doing this on earth now and human being is has all kinds of needs to communicate we are communive species and uh >> if you want to prevent that to impact your observations you remove the humans that's we're doing this on earth already >> right >> you can operate uh radio telescopes from remote >> for yes indeed. What's one thing that you hope that people will take away from this series of articles? Coming back to the to to the the articles themselves, >> radio astronomy is highly important for our everyday's lives. It has even a greater impact on the lives of our children and grandchildren and any coming generation. So it's protection and coexistence with active services needs to be ensured even if it means some effort maybe even a significant effort but uh I hope that this series can convince people that it's worth it. >> Well thank you very much indeed for your for your time and for sharing these insights. It's been a fascinating conversation as the road to WRC27 uh continues. Your article series I I believe offers a fascinating look at science cooperation and the innovation uh that help us better understand both our world and the universe beyond it. And if we weted your appetite, this is for you listeners out there on this and want to read some of the articles or are looking for more information, why not go to our website? You'll find it at itu.int. Well, thank you very much indeed. And any last words from you, Julia? >> Well, watch out radio astronomy topics. They influence your everyday's life. >> Dr. Julia Josha, thank you so much indeed for joining us today. >> Thank you, Max. And uh thanks a lot to the listeners. >> Well, thank you for joining us for this episode of ITU Tech Monthly. And don't forget to subscribe your favorite podcast platform for more simulating discussions on technology and its impact on our world. We look forward to catching up with you again very soon. ITU Tech Monthly was directed and presented by me, Max Jacobson Gonzalez, produced and edited by Jennifer Mloud, and our studio manager is Daniel Baldu. Until next time, stay curious and keep innovating. ITU Tech Monthly is an ITU digital production.