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SEASON 2 - Space

Solar System – Part 2

Siyona August 8, 2020 59 1 4

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Hello there,

       Thanks for holding up your curiosity for a week. We complete our conversation with Dr Guruprasad on so many more things about our Solar System. Why there’s a race to Mars all over the world? Why we cannot grow trees on Mars? How about some school trips to Mars? Finally, I clearly understand why Pluto is not a planet!

Dr Guruprasad gives a lovely inspirational finish on how or what we could do to become future Space scientists… I really hope you get inspired.

Enjoy some space time!

Thank you.



[0.01] {Background Music}

[0.08] Siyona: Hello everyone, welcome to another episode on my podcast, Little Mind Chats. Minds are little, not our thoughts. I’m your host Siyona. Last week, as part of our Season 2, Space, we started a very interesting conversation with an Ex ISRO space scientist, Dr Guruprasad and our topic of discussion was the ‘Solar System’. We got to hear to only part of our conversation. Let’s end it today with a lot of more fascinating facts.

[0.40] Siyona: Oh! And for those waiting for the fortnightly news, it’s coming up this Wednesday instead…! Watch out for an extra mid-week episode this Wednesday.

[0.51] Now, Let’s continue listening to what Dr Guruprasad has to tell us about…. Mars to start with…

[0.58] Siyona: “Why is Mars being explored the most compared to other planets?”

[1.04] Dr Guruprasad: All the four planets of the Solar System, in the inner Solar System Mercury, Venus, Earth and Mars, they have somewhat similar composition. They are solid surfaces, they are made up of rocks, silicates kind of thing. Mars in terms of diameter, I would say it is about 60% the diameter of the Earth. But if you stand on the surface of Mars, your temperature will be many a times less than that in Antarctica. +450degrees centigrade is not there. It is like somewhat, a bit worse than Antarctica. And you know, there is water on the surface of Mars not seas, oceans and lakes. Water vapour is there on Mars. Okay?

[1.49] Siyona: Oh.

[1.50] Dr Guruprasad: And ice and snow. Yes. Snow is there on Mars. Yes, very much. Not liquid water. It has not been found, in the sense in large quantities. Here and there it may appear, this or there and that is different. And you know, more than anything else, Mars has got an atmosphere. But it is 100th as thick as that here on earth.

[2.14] Siyona: That thick!!

[2.15] Dr Guruprasad: So, from surface of the earth you take concord flight or you sit in a fighter plane and go to a height of not even fighter planes will go. Some special planes will go to a height of 30km, whatever is the air density here that is the density of air on the surface of the earth. Of course, it is carbon dioxide again. You can’t breathe. But at least you will not incinerate. You will not be asphyxiated. Of course, you will not be crushed. And one more interesting thing about Mars is, on earth it is 24hours and on Mars it is 24hours 39minutes that’s all. Similar to earth.

[2.54] Siyona: Oh My Gosh!!

[2.55] Dr Guruprasad: You have sunrises. Yes, yes. So, all these things have endeavoured mars to human beings. That is why dozens of spacecrafts have been launched today. Even July 21st early in the morning we had the launch of a Mars spacecraft from the United Arab Emirates which was launched by Japan. Now this spacecraft is on its way to Mars. 

[3.22] Siyona: Really!

[3.24] Dr Guruprasad: Yeah. That’s the way it is. You go and read it.

[3.26] Siyona: Oh My Gosh! (Astonished)

[3.28] Dr Guruprasad: Yes. You can see in the YouTube. You can see. And two more spacecrafts are being launched towards Mars this month, one by the United States, another rover is going and mini helicopter is going to the surface of Mars and a Chinese lander is also being launched. See, see how much human beings are thrilled by Mars.

[3.50] Siyona: Yeah.” But if there is just carbon dioxide on the surface of Mars, then how can we breathe?”

[3.51] Dr Guruprasad: You can’t. At least for the time being, how Neil Armstrong stood on the surface of the moon? Where not even carbon dioxide is there. Okay? Nothing is there. Moon doesn’t have an atmosphere. So, you have to carry your own oxygen and whatever exhaled carbon dioxide is there cleansing that all those things have to be carried. So, artificially you have to be there on the surface of Mars. May be after tens of thousands of years, may be something else may happen to make Mars more habitable. That habitable may make Mars have conditions which are suitable for people to live. 

[4.40] Siyona: Probably we can make it more habitable by planting lots of tress on Mars?

[4.45] Dr Guruprasad: No. We cannot plant trees on the surface of Mars. Because you know any tree, any plant to grow, the seed to become plant or a tree you need nutrients. More than anything else, what we see a bio mass that is, the remains of dead plants and animals what we see is humus. That is not there in the soil of Mars. No. For the time being it is not possible to plant trees on Mars. No, no, no.

[5.15] Siyona: Then till humus is formed, by the rotting of vegetable peels and natural wastes. Isn’t it? So, if we took out the natural waste and dumped it on Mars, the humus would form and then we could take a few seeds and plant it there. That way we have humus too! 

[5.36] Dr Guruprasad: Fantastic!! You’re going to become a scientist or already you are a scientist. But you know the kind of conditions on the surface of the Earth, kind of conditions on the surface of Mars especially in terms of atmosphere, they are totally different. So, it’s not possible. It is not possible for that to happen now. As of now.

[5.55] Siyona: Aww….

[5.56] Dr. Guruprasad: That’s the way it is. (laughs) After 20-30years chance are that human beings may visit Mars. Chances are quite bright. But still many difficulties have to be, that is they have to be solved.

[6.13] Siyona: So, moving on to our next question, “Why all the confusion about Pluto being a planet?”

[6.20] Dr Guruprasad: Oh. It’s a very, very interesting thing. First astronomers were thinking in the early part of 20th century, that is 100years back or even a little bit earlier, that the way in which Neptune is going round the Sun, it is not normally doing in a very particular way. There must be something else beyond Neptune which must be cooling Neptune and alter its behaviour to go round the sun. Okay? That is what astronomers were thinking. There was a great American astronomer I would say by name Percival Lowell. 

[7.06] Siyona: Yeah.

[7.07] Dr Guruprasad: He was a very wealthy man and interested in astronomy to be more precise. That is the best way to characterise him. He to search for the planet X, that is planet lying beyond Neptune. He didn’t find it. But any way he setup a telescope in Arizona in United States and there a person by name Clyde William Tombar an American again he discovered a data flight which was later called as Pluto. In fact, I am very happy and proud to say I have touched that telescope by going there to Arizona and looking that telescope. Yes!

[7.51] Siyona: Yeah well that’s like a really good thing to be able to do in your life.

[7.57] Dr Guruprasad: Yeah. Yeah. No doubt about it. All the way I went to United Stated to see that. I have a picture of that. I will send it to you later. And for a long time, people were thinking Pluto was quite big. Quite means at least big. But now we know that Pluto is smaller than our Moon. Moon is one quarter the size of the Earth. 

[8.19] Siyona: (Astonished)

[8.20] Dr Guruprasad: And Pluto is still, Yeah 2200km in the diameter. And not only that, near Pluto objects which are similar to Pluto made of rock and ice so they also were found. One by one they started finding many objects somewhat smaller compared to Pluto, one is comparable to size of Pluto. If you call Pluto as a planet, you have to call those things also as planets. Then everyday if they are discovering things, every week you have to revise how many planets are there in the solar system. You may say 24 today. After sometime you say 48. The astronomers, you know all of them they club together and they’ve formed an association called International Astronomical Union. What they did was, they put three conditions for a body to be called as a planet. One, it should go round the sun. Does Pluto go around the sun? Yes. Very much.

[9.24] Siyona: Yeah.

[9.25] Dr Guruprasad: Then why don’t you call it as a planet? Second it has to in the form of a sphere. It has to be spherical. Isn’t Pluto spherical? 

[9.33] Siyona: Yeah.

[9.34] Dr Guruprasad: Very much spherical. Then why it is not called as a planet? There is a third condition, for a body to be called as a planet, nearby that body there should not be other bodies which are comparable in size to it. In the place where Pluto is there, there are lot of bodies which are quite large and some of them as large as Pluto or almost as large as Pluto. So, Pluto cannot be called as a planet. Take the case of the earth, it is called as planet because there is no other body which is comparable in size to the earth. 

[10.17] Siyona: oh.

[10.18] Dr Guruprasad: Moon is there, but moon is circling the earth.

[10.20] Siyona: Yeah

[10.21] Dr Guruprasad: Not it is not circling the sun. You understood?

[10.23] Siyona: Yeah.

[10.24] Dr Guruprasad: For a body to be called as a planet, it has to be spherical, it has to go round the sun and it should have cleansed all similar bodies nearby.

[10.33] Siyona: Okay.

[10.34] Dr Guruprasad: which Pluto has not done. That is why it is called a dwarf planet. 

[10.40] Siyona: Oh, that’s why! Very interesting.

[10.44] Dr Guruprasad: Yeah. It is quite interesting

[10.48] Siyona: “Why are all the planets and even the sun in the shape of spheres? Why not any other shape?”

[10.55] Dr Guruprasad: Yet another interesting question. These are all coming from scientific minds. Since you are very interested in science, astronomy. You’re interested in becoming a scientist or an astronaut.

[11.08] Siyona: Yes. I’d love to become an astronaut and become friends with the Martians. 

[11.14] Dr Guruprasad: (laughs). Okay. Why because planets have enough material inside and because of that the gravity is concentrated in the centre and from the centre in all the directions it pulls material towards the centre.

[11.36] Siyona: Okay.

[11.37] Dr Guruprasad: And in the centre, you have the gravity concentrated and everything else is pulled from every other direction means the geometrical figure you get is a sphere. That is why planets are spherical. But asteroids are not like that. Sir, “why asteroids are not like that?” you may ask. The reason is asteroids doesn’t contain much material. Asteroids are like pieces of a planet from which a planet could not be formed at all. So there, mass is very less, the material they contain is very less so there is not enough gravity to pull everything towards the centre that is why they look like celestial potato. Okay?

[12.22] Siyona: (laughs) Celestial Potatoes??!!

[12.27] Dr Guruprasad: (laughs) Just for the sake of appreciating their shape you can think of them as potatoes. And even comets are like that. Comets are little bit different from asteroids. 

[12.38] Siyona: “If the Sun is that hot, why haven’t mercury and Venus burnt out yet?”

[12.44] Dr Guruprasad: Forget about burning of Mercury or Venus. A spacecraft launched by United States by name Parker Solar Probe, it has even gone inside the orbit of Mercury. Though Sun is very hot, you know what is the surface temperature of the sun? 6000 degrees centigrade.

[13.07] Siyona: Oh my God!

[13.08] Dr Guruprasad: Here it is 30 degrees centigrade we can’t manage. On Venus I told you it is 450 degrees centigrade. But on the surface of the Sun it is 6000 degrees centigrade.

[13.20] Siyona: Oh my God!

[13.23] Dr Guruprasad: —–Surface for the sun it is plasma. That is gas from the atoms of which electrons are thrown out. So, it is a globule of hot gas. Okay? But still if you are far away from the Sun, your temperature may be more. But there is no risk that one will burn up. And the material Mercury, Venus and Earth, they are all very near to the Sun compared to Jupiter and Saturn. Though they are near, the material in them they are capable of withstanding the temperature which is in the position where they are today and that is why they are not vaporized. But if you increase the temperature, but if you increase the temperature…

[14.10] Siyona: Oh.

[14.11] Dr Guruprasad: Yes. The problem is may be such thing may happen not in our lifetime, may be after billions of years. Now, there are spacecrafts even today there is another European spacecraft also which has gone inside the orbit of Mercury. Nothing has happened to it. Say not only planets, even man-made objects have not been vaporized because they have a heat shield. So, if you are at a sufficiently safer distance from the Sun, you will not be vaporized at all. So that is why Mercury and Venus they are not vaporized. You got it?

[14.50] Siyona: Yeah.

[14.52] Dr Guruprasad: If you go very near then that is what happens. Many Comets they go very near to the sun and whatever you are asking happens to them. You can see the pictures they go and vaporize that’s all. That happens to Comets when they go very near to the Sun. Okay?

[15.08] Siyona: Yeah well, about Neowise, it went close to the Sun but it just burnt out a bit and added another debris scale.

[15.20] Dr Guruprasad: Yeah, a Comet also when it vaporizes, if it ventures too near to the sun, yes it will contribute to the debris trail which already exists in solar system was from 450 crore years back or in different countries we say 4.5 billion years back.

[15.42] Siyona: Oh my God!

[15.44] Dr Guruprasad: Yeah. These are all very, very interesting and thought-provoking things. Yes.

[15.51] Siyona: “If it takes just 3 or 4 days to reach the Moon, would you say we could have school trips to the Moon in the future?” 

[16.01] Dr Guruprasad: School trips to the Moon, not in the next 50 years or something. It is possible. Of course, Neil Armstrong, Edwin Aldrin and Michael Collins and many of their other apocalypse they took three days. May be a day or two they stayed there and they back within about a week. Roughly everything was over. That is the route taken by them. If you go in a slow speed you can take more than a year to reach the Moon. On the other hand, the spacecraft which is now going very near to the sun. Okay?

[16.36] Siyona: Yeah.

[16.37] Dr Guruprasad: That was launched at such a high speed. It would have crossed the earth-moon distance in a few hours. It all depends on your speed. But in order to make tourism to Moon possible, especially by school students, you need to perfect better technologies. Now a days we are using rocket only once by and large. May be space-X, Falcon 9 is there that is partly usable. So still lot of technologies, new technologies have to be perfected then chances of moon becoming a tourist destination will be a reality. No doubt about but tending towards reality. That’s all I would say. And may be such technologies have to be developed by people like you after few years. Who knows? You are asking so many questions and your podcast many, many students children will be listening to that. If they are inspired a little bit and they think more on these things, rather they can develop such technologies and human beings can take a trip to Moon. It might be possible for common man and students also to go to Moon but lot of new technologies have to be developed. Okay?

[17.53] Siyona: Yeah. 

[17.55] Dr Guruprasad: Rather than the Earth to go to Moon it is easy because Moon is at a distance of hardly 384000. But if you want to go to Mars, you have to travel by today’s technology it takes nearly 8-10 months. 

[18.07] Siyona: That’s… a lot of months.

[18.10] Dr Guruprasad: Yeah. Yeah. Yeah. To travel to other stars from today’s technology it is next to impossible. That’s why I said in the next 100years what new technologies will be developed it decides as to which are the places human beings are going to visit as well as more and more people go to space to go to other planets or comets or asteroids they visit may be as tourists and may go to other stars systems also. It all depends on technology and it takes time for things to develop and it is for kids like you. It’s not only listening to me or any to other person who speaks on science, you have to think beyond whatever we say. Okay? And question thing. That is how you can improve yourself; you can contribute to your family you can contribute to your country and contribute to the world at large. So that humanity will be benefited totally in many ways.

[19.13] Siyona: Yeah… like Albert Einstein said,” Imagination is more important than knowledge”. We need to work hard, imagine and apply.

[19.25] Dr Guruprasad: So, I hope you have finished all the questions for this session.

[19.27] Siyona: Yes.

[19.28] Dr Guruprasad: So, we’ve learnt about the fascinating things about the solar system, about Mercury, Venus, The Moon, The Mars and about even asteroids and curious questions about we visiting them. Especially the students.

[19.46] Siyona: Yeah.

[19.47] Dr Guruprasad: So, it all depends upon people like you, kids like you, interested kids like you. You have to take interest study well do mathematics well. At a later date, don’t worry about it, not at your age. Read well, understand well, ask questions to people and enjoy science. That’s what I want to say.

[20.05] Siyona: Yeah. That was so much more educative than I thought. I’ve found a new rock star in my life. Space is so much more happening than I ever thought before.

[20.17] Siyona: “Can you please help us understand what we as children could do to be a scientist like you, doing all these cool things up there in space?”

[20.27] Dr Guruprasad: I work as a scientist in ISRO for Indian Space Research Organisation for more than let us say 30years. And totally I put in a service of 37years. Later I was trying to talk to kids like you and after I left ISRO now I’m an independent science writer and broadcaster now today. 

[20.48] Dr Guruprasad: So, what you to do to become a scientist and to do good things for humanity is, take interest in science. Be disciplined in life. That is very important. You have to have discipline. Respect your parents and teachers. And more than that understand the subject well. WHY? HOW? WHAT?. Not only what, asking about what. Why and How you should question. Think it over, read well, do mathematics well at a later stage and definitely you will make a good scientist and I would say good luck to all of you. To you Siyona as well as the people who will see this podcast. Thank you, Thank you very much. I enjoyed talking to you and through you to all the guys there. Thank you, Thank you very much.

[21.38] Siyona: You’re welcome! And thank you so much for being on my show. I’m sure I’ll get back to you with so many more questions very soon.

[21.48] Siyona: That brings us to the end of this conversation with one great mind. I still can’t say good bye!

[21.55] Siyona: If you have more questions for Dr Guruprasad, I’d love to help you get your answers. You could get in touch with me on Follow me, share and like us on Facebook and Instagram. 

[22.12] Just in case you don’t know what this month’s competition is, its “Grow Your Greens”. Just pick up some seeds from your kitchen, sow then and wait for a week or so to see some really tender green shoots popping up. Send me pictures of your saplings and then their plants to win some exciting prizes.

[22.36] Thanks a Ton for listening, Bye.

[22.39] {Closing Music}

Download now: Solar System – Part 2

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