Episode 7: Under African Skies

with Dr Tanya Edwards and Dr Simon Bihr

In Episode 7 of the Cosmic Savannah we chat with Tanya and Simon about their astronomy at Namibia’s HESS Telescope and the VLA in the USA.

We also chat about their incredible journey through Africa on bicycles and their experience of the magnificent cosmic savannah!

This week’s guests:

Dr Simon Bihr & Dr Tanya Edwards

Episode Links:
HESS: https://www.mpi-hd.mpg.de/hfm/HESS/

Featured Image courtesy of Janus Brink


(By Lynette Delhaize)

Dan: [00:00:00] Welcome to The Cosmic Savannah with Dr. Daniel Cunnama

Jacinta: [00:00:08] and Dr Jacinta Delhaize. Each episode we’ll be giving you a behind the scenes look at world-class astronomy and astrophysics happening under African skies.

Dan: [00:00:17] Let us introduce you to the people involved, the technology we use, the exciting work we do, and the fascinating discoveries we make.

Jacinta: [00:00:25] Sit back and relax as we take you on a safari through the skies.

Dan: [00:00:34] Okay. Welcome. What do we have in store today?

Jacinta: [00:00:38] So we have a really exciting, very different episode today. It is about astronomy. At least it starts about astronomy and then it meanders in different directions, and then it does come back to astronomy in the end. Our podcast is about astronomy.

It’s also about astronomers and their lives and what they like to do. It’s also about Africa and the cosmic Savannah. I won’t say too much about what we’re talking about today because I don’t want to ruin the surprise, but part of what we’re going to talk about is multi wavelength astronomy.

So we need to use all of the electromagnetic spectrum, all of the different wavelengths of light to do astronomy. And that’s because we can see different things at different wavelengths.

Dan: [00:01:30] Yes and particularly in this episode we’ll be talking about HESS. The high energy spectroscopic system, which is a gamma ray telescope situated in Namibia. A gamma ray telescope is quite an interesting construct because you can’t actually detect gamma rays directly from the surface of the Earth.

Gamma rays are incredibly high energy particles which come from high energy events in the universe stream across the galaxy and intergalactic space and reach us. And what happens when they hit our atmosphere is they interact with other particles within the atmosphere and cause a cascade of highly charged particles and something called drink of light and what HESS does and other gamma ray telescopes actually detect that cascade.

The kind of collateral damage from the gamma ray hitting the atmosphere and reconstruct the gamma ray path that would have caused this cascade.

Jacinta: [00:02:37] Yes. Then you can figure out which direction the original gamma ray came from, and therefore what astronomical source on the sky probably produced it.

Dan: [00:02:47] You’re not directly observing gamma rays, but you’re observing their effects. And from that you can infer what energy they were and where they came from.

Jacinta: [00:02:56] And we also talk about some radio astronomy called HI – neutral hydrogen. It’s an emission line from the hydrogen atom, and that’s very close to my heart.

It’s what I did most of my PhD research about. This episode doesn’t necessarily focus on it. I promise you we will have many episodes talking about it in the future if I have anything to say about it but we will mention it. I guess different atoms and different molecules emit different emission lines so these are narrow frequency photons of light. They are kind of the signatures of these atoms and molecules. And if we detect them in space, then we can figure out what atoms or molecules are out there and that can tell us where the clouds of molecular gas and atomic gas are and therefore where the clumps of newly forming stars are. So that can tell us about the geography of our Milky way.

Dan: [00:03:55]  So, who are we speaking to today?

Jacinta: [00:03:59] So today we are speaking to two pretty incredible people.  Dr Tanya Edwards and Dr. Simon Beer. They are from South Africa and from Germany, and they have a pretty incredible story about how they traveled from Heidelberg in Germany where they did their PhDs to Cape town here where we are.

I don’t want to spoil the story so let’s hear from them.

With us today are Dr Tanya Edwards and Dr. Simon Beer. Welcome Tanya and Simon.

Tanya: [00:04:40] Thank you. Thanks for having us.

Jacinta: [00:04:42] Tanya and Simon, you have a really interesting story to tell us. I guess it starts in Germany in Heidelberg, where you were doing your PhD in astronomy. Can you tell us a little bit about what you were working on?

Tanya: [00:04:56] Sure. I grew up in South Africa and I went to England to do my bachelor’s and master’s degree there. Then I moved to Germany where I did my PhD in Heidelberg. So there are two Max Planck institutes in Heidelberg and I did mine at the Max Planck Institute for nuclear physics with the HESS group.

 That’s actually where I met Simon. So the HESS group is actually a collaboration of about 14 countries and many scientists working together on high energy gamma ray astronomy or other very high energy gamma ray astronomy. We detect gamma ray showers between a hundred GeV and a hundred TeV.

Jacinta: [00:05:37] So very, very high energy, high frequency waves.

Tanya: [00:05:40] Exactly. The telescope is actually located in Namibia just Southwest of Windhoek in the Gamsberg area. It has very good conditions for observing. I was lucky enough to go and do two shifts there and just enjoy the beautiful sky, enjoy observing with the HESS telescope and also working with amazing colleagues in Heidelberg. I did a lot of image analysis. What the HESS telescope does is it detects Cherenkov light. So there’s a lot of cosmic rays and high energy particles and gamma rays that are coming into the atmosphere and they produce extensive air showers.

And these air showers actually produced something called Cherenkov light, which is produced from the molecules in the atmosphere and how charged particles interact with them. Our telescope actually reflects and detects images of this light. We do a lot of image analysis where we kind of check the shapes of the images that tells us what type of particle comes into the atmosphere.

So my job was kind of figuring out which particles are coming in and trying to find the differences between electron showers and gamma ray showers because they’re very similar.

Jacinta: [00:06:55] Fantastic. What was it like to observe with HESS in Namibia?

Tanya: [00:06:59] Yeah, it was quite spectacular.  A lot of the time we were also inside looking at the showers and checking which sources we’re observing. In Namibia we would do a lot of hands on work with the cameras as well. We’d go out and do a lot of checks on the actual telescope so we could have very hands-on experience with the telescope there. So not as automated as some people would assume, because it is still a very new area of astronomy, and the technology is still developing, but it’s amazing to see the cameras in action and how fast they can record these showers, because it’s on the nanosecond scale, you have to have very sensitive, very fast cameras.

Just working with the cameras, working with which sources we’re observing and seeing these showers pop up on the screen, almost in real time. It was pretty amazing to see cosmic rays entering the atmosphere and gamma rays and seeing science in action.

Jacinta: [00:08:00] Wow. It’s all very fast timescale stuff, which I guess I’m a radio astronomer and I’m not used to that. Things are just very slow and always there most of the time. What does a gamma ray telescope actually look like?

Tanya: [00:08:13] The HESS array has five telescopes. Four of them are spaced 120 meters apart from each other, and they are 12 meters in diameter. Then we have an upgrade of a very massive 28 meter fifth telescope that’s placed right at the center of the array. This is very sensitive. Much more sensitive than the other telescopes. So actually, you can do mono observations with them, which is interesting for a lot of science.

Jacinta: [00:08:42] What’s a mono observation?

Tanya: [00:08:44] Where you just observe with one telescope. Usually in a stereoscopic system, you need more than one telescope to observe because when a shower enters the atmosphere, you can’t pinpoint the direction with just having one image. If you have two images, then basically you can draw a line through the image and where these lines intersect is where the source of the shower came from and where the particle entered the atmosphere. You can also more accurately predict the energy of the shower. So you can look at something called image size or how much light is basically collected in the telescope and then you can average them between all of the telescopes and then see exactly what energy you’re dealing with.

Jacinta: [00:09:28] So we’ve discussed on this podcast before that a radio telescope looks something like a satellite dish.

And there’s also lower frequency radio telescopes that kind of look like metal umbrellas on metal spiders and optical telescopes look like traditionally what we see, how’s the big domes, big mirrors. What does the actual telescope of a gamma ray telescope look like?

Tanya: [00:09:49] So we actually have segments of hexagonal mirrors that are placed together, almost like a puzzle, and it’s in a parabolic shape to collect light and focuses that light onto a camera, which has very sensitive PMTs. It’s 12 meters and 28 meters so not as big as radio astronomy you would expect but it’s still very impressive when you see it. Each segment has to be replaced every so often and the mirrors have to be coated every so often.

Yes essentially the same principle, collecting light and focusing it onto a specific area.

Jacinta: [00:10:25] Really amazing stuff. And Simon, you’re from Germany, and you also did your PhD in Heidelberg, is that right?

Simon: [00:10:31] Yeah, correct. I grew up in Germany. I did my diploma already in Heidelberg, so that was physics.

I was also one year in Canada and then I did my PhD at the Max Planck Institute for astronomy. So that’s the second Max Planck Institute in Heidelberg. I was working in the staff formation group of Henrik Boyter, but I’m also a radio astronomer. So we did observations of the HI line. The Hydrogen line.

We were using mostly the VLA, the very large array in New Mexico. We had a large program with them. We had over 200 hours observation time, which then obviously relates or gives us a lot, a lot of data. I had the joy and pleasure to work through these two terabytes of data. I also had the chance to use other telescopes to observe.

So I was at the Effelsberg  a hundred-meter telescope, so they can really do hands-on observations. Effelsberg is close to Bonn also in Germany. I think it is the second largest single dish radio telescope in the world. It’s very impressive, if you sit in front of this telescope, you play around with your computer and it actually moves, cause at the VLA it’s different from the HESS telescope what Tanya just said.

At the VLA, you never go to observe because you just write your scripts how you want to observe. You send this to the operators and operators do the job for you.

Jacinta: [00:11:50] All right, so Tanya was saying she had to do a lot of the observations herself, but you’re saying that this is, you don’t actually have to do it the operators will do it.

Simon: [00:11:57] Correct because they have a dynamic scheduling. They are always looking for the conditions and then they see which program they do at what time. So you also never really know when you will get your data. I think it’s the same with ALMA nowadays.

Jacinta: [00:12:10] . What were you actually looking at with the VLA and Effelsberg?

Simon: [00:12:14] So we had a program that was called Thor. It was called The HI OH recombination line survey of the Milky way.

Jacinta: [00:12:20] That’s a wonderful acronym.

Simon: [00:12:23] Took us a while to come up with that. We also had always nice pictures of Thor, a guy with a hammer and hammer was smashed on the Milky way. So we wanted to have a large survey of the Milky way, all the star forming regions in the Milky way.

The name already says not just H one, but also use others. Other lines like, O H all the combination lines. And we also had a continuum catalog actually from all the continuum sources in the Milky way, but also extragalactic sources.

Jacinta: [00:12:55] Okay. So you’re looking at the Milky way and you’re looking at an HI, which is neutral hydrogen gas and you’re also looking for the lines from other molecules such as, for example, OH and continuum, which is a little bit different. So that’s also some radio signals. What kind of objects are emitting these things in the Milky way?

Simon: [00:13:16] So depending on the line is completely different. Each one is these big star forming clouds. So, hydrogen clouds where stars then can form, OH is more tracer for the molecular clouds to see kind of the second stage after the neutral hydrogen, if it contracts already. If the clouds form in the center, you usually have molecular hydrogen.

This is one step towards the star formation. We can also trace the molecular part and then the continuum is completely different. Do you have a lot of extragalactic sources? It can be either quasars or something like that. I’m not an expert into the extragalactic part, so I don’t want to go into details about that.

Jacinta: [00:13:57] Okay, so you’ve got big clouds of neutral hydrogen gas in space, and these then condense into molecular hydrogen clouds, which then in the centers of those, that’s where the baby stars are born, right? Cool. So you’re looking for these early signs of star formation and then while you’re doing these observations, you can also see some galaxies in the far background.

These are actually not in the Milky way. These are far away, but they just are along your line of sight where you’re looking right.

Simon: [00:14:27] These far distant sources, they can be very helpful for us because we always see HI in emission. But we can also see the neutral hydrogen and absorption towards these extragalactic sources so we can, so to speak, use the extragalactic sources in the background as lighthouses shining through our HI cloud, and we can then observe and an absorption signal, which gives us extra information about optical depth and how much hydrogen there is actually. So it helps us a lot the combination between the extra-galactic and the galactic.

Jacinta: [00:14:57] Right? So you’ve got these big, huge radio galaxies in the background, which we’ve spoken about on this, on this podcast before, what these radio galaxies are.

And as you say, they’re like a lighthouse, which are like illuminating these clouds of gas, which are then absorbing that light. And then we can see the dip in the light because it’s been absorbed and we can then figure out how much gas is there. Really awesome stuff.  But we’ll move on a little bit from these stories now because we’ve got something else to talk about today.

We’re recording this interview here in Cape town, in South Africa, and you’ve got a really interesting story from how you got from Heidelberg in Germany after your PhDs to here in Cape town. Can you tell us how you got here?

Simon: [00:15:42] So after our studies we thought, okay, I’m from Germany and Tanya from South Africa, so we should combine our two homes.

And we’d not just wanted to sit in a plane. We wanted to experience a little bit more. We wanted to have a big adventure. So we decided, okay, let’s use our bicycles. So we started cycling in May, 2017 we cycled down from Germany all the way to Turkey. Then we took a plane to Cairo, and then our Africa adventure started.

Tanya: [00:16:10] And from Cairo, we follow the East side. So we went through multiple countries. We went through Egypt, Sudan, Ethiopia, Kenya, Uganda, Rwanda, Tanzania, Malawi, Zambia, Zimbabwe, Botswana, Namibia, South Africa. It’s a lot to remember. We did about 19,000 kilometers on the bike now.

The idea was to connect Simon’s hometown to my country. It’s been an amazing adventure until now it’s taken us almost two years.

Jacinta: [00:16:48] That is absolutely phenomenal. So you rode your bicycles from Germany down to to Cape town over the span of about

Simon: [00:16:55] two years.

Jacinta: [00:16:57] I mean, I didn’t even know where to start with questions on that.

 It’s so different. I guess firstly, what inspired you to do this?

Tanya: [00:17:05] I think it was sort of a joint idea in the beginning. I always wanted to travel. I knew I wanted to travel and I was thinking more along the lines of six months. Then the idea just grew. Simon wanted to explore closer to home, which makes sense because, you know, you should take opportunities to see countries that are close to you.

And I was really keen to see Africa. Then we thought, well, how can we make this cheaper, first of all, how can we make it more adventurous? And then we came up with bicycle touring.

Simon: [00:17:41] Yeah. I think it also grew over time because at the beginning we always thought, okay, let’s just buy a bus, do the classic van life in Europe, you know, maybe tour around with the full van.

But then we decided, no, the bicycle are a better transport mode because you’re very close to nature. First of all, you’re very close to the people. You feel everything, you smell everything. You have the wind in your face. You also are not a threat to people. If you come with a bicycle in a small village or so, people are always curious about you.

They speak to you. If you come in for a bit in a big car, usually just go through these little villages. You know, we have to stop. We have to find water, we have to buy food. We interact with the locals. And this gave us a very, I think, unique insight into Africa.

Tanya: [00:18:25] Yeah. Your senses are almost always alive.

There’s a million things happening at the same time and you have to concentrate on that, but it gives you a lot. It’s very hard work, and it takes time to get used to it, especially your body. I mean, sometimes you have  a lot of pain in your body, but then after about one or two months, it just says, okay, this is my life now. I better get used to it. And it’s been fine and fantastic since then.

Jacinta: [00:18:54] And were you happy with your decision to do this? How did you enjoy your adventure?

Simon: [00:18:58] I think we were very happy about it. You always have ups and downs. I think that’s every life. Also in two years you have some down points where you feel like, ah.

So, but most of the time we were very happy about it and we’re very confident that this was the right decision. Sometimes when you cycle a hundred kilometers a day, you’re really tired. Your legs are sore, but then you camp somewhere in the middle of the bush. You have a beautiful sunset and, and you just feel like you’re totally free.

You can move wherever you want. You can stay wherever you want. If you’re lucky, you might even see an elephant in the distance walking by or so. These are just moments where, you know, okay, all the pain, all the sufferings, totally worth it.

Tanya: [00:19:39] Namibia was quite difficult for us because a lot of the roads were very, very hard.

And when we got to Cape town, you know, we thought, okay, we’ll give ourselves a break. We’re off the bike and it’s going to be fine. And then we took the car to Simon’s town and we’re just like, oh, we wish we were on the bikes again because it’s just a totally different feeling around you.

 I think we really enjoyed it. I learned a lot about myself. I learned a lot about the world, people, how I interact with people and my perspective on a lot of things has changed because of this trip and I’m very grateful for that.

Jacinta: [00:20:17] So I’m sure you’ve got so many stories.Top 10, top 100 stories. Can you think of one or two that you might like to share with us?

Tanya: [00:20:27] Well, I think one of the most exhilarating moments was when we were wild camping in Kenya and an elephant crossed like just five meters from our tent on an elephant highway. We heard this amazing rumble, those deep rumbles that they use to communicate with.

Simon: [00:20:46] And it was in the middle of the night at three in the morning.

Jacinta: [00:20:48]  Oh my goodness.

Tanya: [00:20:51]  It wasn’t something I’d heard before. You just have to trust that elephants are intelligent enough. They don’t need to kill you for just any reason. Sometimes things happen, but we just had to trust it.

We couldn’t do anything about it. We realized that it just crossed. Then in the morning when we were having breakfast, it also was probably the same elephant that was sleeping in a bush in front of us the whole time we had breakfast and we’re packing up our stuff and then it notified us politely. Hey, don’t come close. I’m in this bush. Then we just turned around and then, we left the area. 

Simon: [00:21:27]Another highlight for us was I think the people in Africa. In Europe and in the Western world, people usually think of Africa as kind of the poor and dangerous continent where you should not go but it’s absolutely not the case.

People were super friendly to us. One of the highlights was Sudan. A lot of people think of Sudan as the war zone, and you shouldn’t go there. But people invited us all the time for coffee, for even having lunch, or we also could stay at their places. One example was we had a rest day in Dongola, a small town.We just went out for breakfast. We didn’t want it to do anything on that date and just, you know, relaxing in our hotel room. But then in this cafe, there was a guy who started chatting to us in French. My French is not very good, but we could at least exchange a few words. And then he invited us to his village, which was a little bit outside of Dongola.

He said, come with me. I show you my family, I show you my place, and blah, blah, blah. So we said, okay, fine we have nothing to do today. So we went with him. He was super nice. We got to know his family. His place. And it turned out that he was a big fan of drones. So he actually had a drone from France and we ended up in the evening for the sunset on the Nile in a little boat followed by the drone.

And we have amazing pictures and videos of that. So it’s just like totally unexpected.

Jacinta: [00:22:45] Not the sort of thing you might expect.

Simon: [00:22:47] No, no. Especially not in Sudan. This is something you would not expect.

Tanya: [00:22:52] Another thing we didn’t expect was to come across a wild rhino in Namibia. So we were both just eating breakfast.

I was eating breakfast on the road, and I looked up and then there’s a rhino walking towards us,  which didn’t know we were there clearly. So eventually we ran behind a bush, and of course Simon went back to the bike to grab his camera just to make sure he could shoot it properly.

Simon: [00:23:19] Tanya was not happy about that.

Jacinta: [00:23:21] You ran back to the bikes, but the thing you grabbed was the camera

Simon: [00:23:25] Well, the bike was just two meters in front of us.

Tanya thought I got either the Swiss army knife to protect us or so, but, I just took the camera.

Jacinta: [00:23:35] I’m not sure a Swiss army knife would work against a rhino.

Tanya: [00:23:38] but the intention would have been nice. We ended up going behind a bush and then a larger tree and then, it had a standoff with us and made sure it looked very scary. Which it did look very scary.

And then after it grunted and turned to the side, it just decided to run off instead of charge. So in general, the wildlife has been incredible to see, but I think we’ve also had some very close experiences. Including, cycling past lions as well, which we did.

Simon: [00:24:07] And it would have been actually quite hilarious if a rhino would have attacked us because we actually called our trip rock, road and rhino.

So rock for rock climbing, cause we did a lot of rock climbing in Europe, rode for the cycling part and a rhino we’re to try to raise awareness and funds for the rhinos. And if a rhino attacked and maybe even killed us, that would’ve been not good.

Jacinta: [00:24:30] Yeah, I was just gonna ask you about your road, rock and rhino name.

Tell us more about the rhino part.

Simon: [00:24:36]  The rhinos have a big problem in Africa and all over the world. They are close to extinction. There are several reasons for that. One is habitat loss, but another big point is also poaching.

Unfortunately, people think that the rhino horn can cure any diseases, but it’s basically a horn.  It’s like the same as chewing your fingernails. That has exactly the same effect, but people don’t want that. So the rhino horn is extremely valuable. It’s more valuable than gold. So you have to imagine you have this massive animal walking around with something like two kilograms of gold on its nose.

And that obviously attracts a lot of people and they kill the rhino. They chop off the horn and then they leave. It’s a big problem here in South Africa. So we wanted to raise funds and awareness for a UK charity. This is called Save the Rhino. They help all kinds of different projects and we could also visit some of their projects in Africa, especially two projects in Kenya.

One was called Borana, it’s the private conservancy and Ol Jogi, and we could see what they do with the rhinos there and it was just fantastic to see their work. There was also one rhino baby, called Meimei. I think Tanya wants to talk about that.

Tanya: [00:25:57] I got to give this baby rhino a mud bath, and it was absolutely adorable, but to see the work that they do there at Ol Jogi especially with Meimei.

In her case, she was born blind and she would have lost her life if she had stayed in the wild with her mother. So they took her in and then they treated her eye and now she can see properly and they’re teaching her how to feed, how to bath do all of these things. Her carers are basically her mother there, and at four years old, hopefully she’ll be reintroduced more and more often back into the wild.

Jacinta: [00:26:32] And we’re going to put it on our website, some links to the charity, and if people would like to go and contribute to that, they can go ahead and do that. Thank you. Also, another part of your trip was about rock, that’s in your title. Tell us about that.

Simon: [00:26:49] Yeah. So we’re both passionate about rock climbing.

So sport climbing, bouldering, track climbing, whatever you want to call it. In Europe we also had our climbing gear with us, so that means a rope, all the karabiners, harness and helmets. So it was an extra 15 kilograms of weight that we had to carry around, but it was totally worth it cause we cycled from one climbing area to another. Sometimes we stopped there for a week or two and just enjoyed doing a lot of rock climbing and it was really fantastic.

Tanya: [00:27:18]  If you want to know the best spots that we found along the way, you can check out our website and all of that is listed there.

Jacinta: [00:27:24] What’s your website?

Tanya: [00:27:26] www.rock-road-rhino.com.

Jacinta: [00:27:30] Great. I guess we’re getting a little bit off the topic of astronomy, but, our podcast is also about astronomers, and astronomers are people who have a lot of different interests and do a lot of different things with their lives.

So I think this is also something really important to talk about. But our podcast is also about it, it’s called the Cosmic Savannah, and you are both literally seeing the cosmos from the savannah as professional astronomers. It must’ve been incredible to see these nights. Guys, please tell us what you saw.

Simon: [00:28:01] So, we had, I think two highlights about the stars and the sky. The first was the Sahara desert in Sudan. There is just no one around you. You have like three, 400 kilometers of nothing more than just sand. So the sky is extremely dark. We’re fortunate that at that point it was also a new moon, so we had no moon in the way.

And then you can just, it feels like billions of stars. It was fantastic. You see the Milky way all the way to the horizon, and we even saw the zodiacal light, which is something I’ve never seen before.

Jacinta: [00:28:39] What is the zodiacal light?

Simon: [00:28:40] So the zodiacal light, it looks almost like the Milky way.

It’s like Milky ish. It’s like a triangle, which you see towards the sunset and it is actually a reflection of dust in our solar system. So we have not just the planets and the comets and all the other bodies in our solar system, but also a lot of dust. And as dust reflects the sunlight you can see it clearly after sunset or before sunrise. And it’s very dark, so it’s a bit darker than the Milky way, but if it’s dark around you, you can really see it.

Tanya: [00:29:18] It was almost brighter than the Milky way at that point.

Jacinta: [00:29:20] Really, it must be quite rare and quite difficult to see something like that.

Simon: [00:29:25] It is very difficult because usually you have a city or a few cities around you always see the light of the cities towards the horizon, so you really have to have a dark horizon around you to see the Zodiacal light.

Jacinta: [00:29:37] Yeah. So I guess light pollution is something that we talk about sometimes and meaning, light from cities and that means that we can’t actually see the night sky.

And very few people who live in cities have ever seen what the night sky really looks like.

Simon: [00:29:51] Yeah. But that was in the Northern part and we also could see the Southern part. 

Tanya: [00:29:56]  In Namibia, I would say it was the next best sky that we saw. I think there were too many villages along the way in the rest of the countries, unfortunately, that we couldn’t see such an amazing sky.

But Namibia has a lot of desert and very few villages. And the sky was incredible, actually, so incredible that sometimes it was hard to distinguish the Milkyway from the rest of the sky because there was just so much of light around, so much of stars around. It was also very hard to pinpoint constellations because there were just so many.

Jacinta: [00:30:34] Too many stars that you could see

Tanya: [00:30:35] We did see the LMC, the Large Magellanic Cloud and the Small Magellanic Cloud, which are dwarf satellite galaxies.

Simon: [00:30:43] it was especially amazing when we could go camping there and I always make the jokes. Then why do you want to stay in a five star hotel when you have 5 billion stars above you.

So that was our 5 billion star hotel.

Jacinta: [00:30:58] Simon had you seen the Southern sky before?

Simon: [00:31:00] So for me, it was the second time that I saw the Southern sky. I was once in Chile where I could see it a little bit, but not as good. So for me, it was just like seeing the LMC kind of you always hear about the LMC and the SMC, and then seeing our neighboring galaxies kind of that large.

And that bright, that was just fantastic. As a person that grows up in the Northern sky  you’re used to the Northern sky also the constellations there. But then the Southern constellations, I got totally lost. I don’t know any of them, but it was very nice to see also another part of our universe.

Jacinta: [00:31:34] Yeah, that must’ve been incredible.

Tanya, you’ve been through Namibia twice now for two completely different reasons. How was the comparison in riding through Namibia and seeing the night sky versus going there for some professional astronomy.

Tanya: [00:31:50] I probably saw more of the night sky cycling through Namibia. Professionally, when you’re there, you’re obviously working at night. You’re doing a lot of long shifts so you can’t be outside. You are always  just observing or admiring the night sky. Although we did have a lot of nice asteroid showers which we could see and we did have a telescope that we could also observe outside of work. But most of the time you have to do a little bit of work. Of course, that’s why you’re there. 

But we could just camp in the middle of nowhere in the desert. We didn’t have to be close to any facilities or any big roads. We took very small roads through Namibia. So I would say probably cycling we saw much more.

Jacinta: [00:32:34]  I guess it’s a bit of a common misconception that professional astronomers are sort of outside looking at the night skies, but that’s kind of not what we do.

In fact, we do that very, very rarely, and I don’t even know the names of the constellations, to be honest. It’s looking at the same thing, but from a different perspective.

Simon: [00:32:53] Right. As a radio astronomer, you can also be lucky and always observe during the day. So in my career, I haven’t had a single night observation.

 I was always lucky and got the day shifts. I could always observe during the day and sleep at night.

Jacinta: [00:33:07]That’s good. I had Christmas night once. Simon being from Germany. What did it feel like for you to discover Africa like this?

Simon: [00:33:18] So in Germany, you don’t hear too much good news about Africa.

So if Africa is in the news, you always hear about either wars or another drought or people are angry and that kind of stuff. So I was a bit skeptical. Now obviously Tanya told me a lot about that. Africa is not like that. At the beginning it was difficult, I would say. So that’s why we also decided to start our cycling trip in Germany.

So we can get used to all the hobo life to cycling. Our bodies could adjust to biking, and also living just outside and attend basically all the time. And then we were prepared for Africa. What I really enjoy about Africa is, first of all, people are much more open. Life happens more on the street.

I would say in Europe, especially in Germany, everyone is in their houses or so, and if you go to certain parts in Africa, Kenya, you always see hundreds of people running around or walking around on the street, which is super lively. Also the market I love going shopping at the markets there.

Where you just have very nice ladies that sell you all their freshly grown products. I really enjoyed this. What was also surprising for me was like, even though some of the people live in very poor conditions, at least what we would say, poor, but they have their family around them, they have their friends around them.

 I think this is a very important part of their life. And they are usually very happy about  their life. So I’m not sure if it’s also a good idea as an European or Western person going there and trying to put your lifestyle on them. I think the lifestyle they are having, most of them are actually quite happy about it.

Tanya: [00:34:59] We could sort of, get a little bit of a feeling about a change in lifestyle. Obviously from our lifestyle, there was a big change from giving up a lot of comfortable things back in Europe, and then, just having a tent, living in a tent, always sitting on something hard. But I mean, if it becomes usual, if it becomes your normal life, then this is comfort for you after a while.

Jacinta: [00:35:21] And Tanya, how was it for you to discover more of the continent, where you’re from and how is it to be back in South Africa now?

Tanya: [00:35:27] Well, I’m very glad we both chose Africa to go through. I think I had a huge perception shift actually because growing up in South Africa, you do grow up with this culture of fear because crime is a big problem here.

And it’s a big focus for a lot of South Africans. But I think  going through the rest of the African countries couldn’t be more different in terms of safety. There was no point where I felt unsafe actually in Africa. I’m also including coming down to Cape town. So there is this, maybe for me, I had a bigger fear that something might happen because of my childhood or growing up out here, but that was completely false. I realized.

Jacinta: [00:36:11] And you’re happy to be home.

Tanya: [00:36:12] Yeah, I am. I’m very happy to be home, so we’re really going to enjoy some weeks in Durbin and enjoy that with family and friends and we’ve really enjoyed our time in Cape town. That’s just been incredible. I think Cape town is probably the most beautiful city in the world.

I shouldn’t be too biased because I come from Durbin, but it is actually a pretty spectacular city as well.

Simon: [00:36:34] I can confirm that. I’m really impressed by Cape town. We’ve been through a lot of big cities, or we usually try to avoid the cities because they’re not so good for cycling, but Cape Town that was like, wow. Seeing Table Mountain, seeing the ocean next to you. Perfect place.

Jacinta: [00:36:50] This episode is sponsored by Cape town tourism.

Simon: [00:36:56] Tanya’s family is also quite happy that we are back now because I think  they usually see kind of their local crime ratesI in Durbin. They were super afraid that we would go through Africa. So were also my parents, and I think they are all happy that we are done with the trip, that we survived the trip and that we’re back home soon.

Tanya: [00:37:18] But I think there’s not too much need to worry about that. Yeah, that’s true. There’s a lot of things that we’ve taken from the trip, but definitely, not to judge people too quickly and to always give someone a second chance. I think these are two big things for me. Also to always be open to any person from any cultural background or any class background. You can always learn something from them and you can always make their day a bit brighter.

So just try and be open to people.

Jacinta: [00:37:50] And as astronomers we’re quite aware that, you know, this is the only planet that we have. There are none, no others anywhere near us that we found that we can live on. We haven’t found another inhabitable planet yet at all. So we really have to take care of this one.

Did you learn any messages about the environment and environmental care on your trip?

Simon: [00:38:07] Yeah, I think environmental problems. Well, all over the place here on the planet in Africa in general, we saw a big difference between countries that have a lot of garbage. For example, we saw lots of garbage and for example, Egypt, they don’t have any disposal system or anything.

But then we also saw places like Wanda where they just banned plastic bags or plastic in general and the country’s super clean. There are no environmental problems about plastic and that. And so I think a lot of countries could, you know, take this as a role model and also use that Piney introduced it now a little bit.

I think we have to be very careful with our own environment, with nature. We also have to give a lot of space to wild animals in my opinion. Population growth is one of the biggest problems here in Africa, especially for the wildlife that just uses a lot of space. We also have to come up with alternatives for cooking.

Charcoal is one of the biggest problems in Malawi and Zambia. They just chopped down all the forests to cook, so we have to come up with better ideas for that. This is work in progress, but I think these are very, very important topics.

Tanya: [00:39:20] Yeah. I think the environment was actually one of the biggest shocks for us. Actually not just going through certain countries in Africa. Also, it already started back in Europe. Croatia for instance, was a very big shock. There was plastic. Dumped plastic everywhere in bushes,  which you don’t see going past in a car. We actually did one stretch in a car and my parents were like, commenting, this is very clean.You know, Croatia is very clean. We did the same stretch with a bicycle the next day, and you see the details, you see all the different plastic stuck everywhere, and there’s also a lot of different dumps in certain areas. This continued in Montenegro and Albania. Greece and Turkey, not as much plastic, but a very big problem with stray cats and dogs.

There’s 1 million stray dogs in Greece right now, and, um, the situation is also getting a little bit out of control. Africa didn’t have so many stray animals  and I think in general a little bit less garbage, but in certain parts, whenever we would go through the Sahara desert and we wouldn’t see anything, it would just be absolutely clean. Beautiful.  

Then we’d see one cafe on the side of the road just for people to stop or trucks to stop. And around this cafe, just tons of plastic bottles and plastic bags that have either caught on bushes or flown off into the desert. And this was just one tiny cafe, and we would see this repeating often or one small village.

There’s just, plastic has been introduced into societies which don’t know how to handle them. And there are no disposable systems, no recycling systems, and there needs to be more of an effort, a combined international effort into handling plastic, especially in poorer communities.

Simon: [00:41:03] And we also think that it’s not just recycling, that should be improved, but also everyone should consider their own use of plastic and garbage in general.

So I think that besides recycling the best is actually to avoid it. That means maybe you can refill your bottles at home, maybe, you know, introduce a filter at home so you don’t have to buy water. You can just reuse the same bottle over and over. We actually have plastic bottles from home that are still, that’s still survived for two years and they’re still, okay.

You sometimes have to clean them, but that’s not a big deal. Also, try to avoid maybe, you know, take away coffee or if you want to ever get take away coffee, bring your own mug. You know,  everyone can do it themselves. And I think if everyone would do that, that would also be a big step towards the right direction.

The next thing is we obviously also want to promote cycling as a means of transport. It’s not just a fitness thing. It’s also  if you could have a city which is full of bike lanes, where everyone can just cycle, this would be for us a dream city. You know, we don’t really need a car here in Cape town. I can understand that the traffic is very dangerous.

It’s very hectic. It’s difficult to commute, but I think everyone should also try to promote that a bit more.

Jacinta: [00:42:19] Well, it sounds like you’ve gone from experiences where you’re doing your PhD, staring at the skies all the time, having your heads in the cosmos, so to speak, to a very, very grounding, humble experience.

So thank you so much for sharing your experiences with us today.

Tanya: [00:42:36] Thank you very much.

Jacinta: [00:42:46] So pretty epic stuff. Dan, you didn’t get to be there for the interview, so what did you think?

Dan: [00:42:52] Yeah, I really enjoyed it. It was really great to obviously hear about the astronomy that these guys do. And their experience in terms of their studies and visiting telescopes and things. But cycling through Africa, it definitely triggers a lot of wanderlust in me.

Jacinta: [00:43:13] You’re quite an athlete yourself aren’t you?.

Dan: [00:43:15] Yeah.Absolutely something I would love to do. It sounds like an incredible adventure. They had an incredible time and saw some unbelievable sights, seeing the zodiacal light and all of the interactions with animals. You know, under African skies and, as you mentioned, the cosmic Savannah that we sort of like named our podcast after.

It’s really quite special and I think, yeah, very, very lucky.

Jacinta: [00:43:52]  I thought it was, I thought it was incredible. I was blown away by the zodiacal light story. I don’t even know what it would look like. They said it was even brighter than the Milky way at one stage, which is just amazing.

 I haven’t, myself had much of a chance to travel far outside of Cape town yet, so I haven’t seen much of the rest of South Africa, let alone all of Africa. And their story just inspired me so much to go out there and see it because wow, what amazing things and people and animals out there.

Dan: [00:44:28] Not an insignificant athletic achievement other than 19,000 kilometers and they didn’t talk much about that. 

Jacinta: [00:44:35]  I’m not much of an athlete myself, but you can talk more about this, Dan, because you have not one but two silver medals in Comrades. What is it, an ultra marathon or

Dan: [00:44:47] it’s an ultra marathon, about 90km.

 Jacinta: [00:44:49] So that’s pretty good. You know, about pushing your body right.

Dan: [00:44:53] Running but doing it day after day like that for two years. It’s really quite something. They seem to have taken it in their stride and managed to enjoy the journey. It’s wonderful.

Jacinta: [00:45:08] Yeah. Pretty awesome. Well, I guess that’s it for today.

So thank you very much for listening and we hope you’ll join us again for the next episode of the Cosmic Savannah.

Dan: [00:45:20] Thank you. And as always, you can follow us on Twitter, Facebook, or visit our website thecosmicsavannah.com where we’ll have links related to today’s episode.

Jacinta: [00:45:30] Special thanks today to Dr Tanya Edwards and Dr. Simon Beer for speaking with us.

Dan: [00:45:36] Thanks to Mark Allnut for the music production, Janus Brink for the Astro photography and Lana Ceraj for the graphic design used to create the podcast art.

Jacinta: [00:45:44] This episode was created with the support of the South African national research foundation and the South African astronomical observatory.

Dan: [00:45:51] If you’re enjoying this podcast, you can help us by subscribing on Apple podcasts, Spotify, or wherever you get your podcasts and leaving us a review.

Jacinta: [00:45:59] We’ll speak to you next time on The Cosmic Savannah.

Dan: [00:46:08] Next time on The Cosmic Savannah.

The question then, because you know, how do we get from the formation, the earth, all the way back to the big bang, right? How do we put that entire story together? And that’s basically what I’d like to do, right? This is what we tried to do using big supercomputers because it’s very hard to, you know, think and just  write down all the things that might happen. So instead we try to put it out on a computer and let the computer do the thinking for us.