Some more questions about the Solar System and Space by Seb, Luke, Luca, Sammy and Bowen

Many thanks for your questions. I told the last group that, 3 days ago I visited the Kennedy Space Centre in Orlando. It was brilliant. I was particularly interested in their idea to visit Mars in the near future. However let us look at the other superb questions and see how many other questions they create….that is what science is about.

Seb asked  “What does Mercury orbit?”

Seb, many thanks for the question. Not long ago, in our history, everybody thought that the Sun orbited the Earth. Why shouldn’t they? You see the Sun rise everyday and move across the sky and then disappears on the opposite horizon. It moves, we don’t.

Or could it be the other way – the Earth moves and the Sun stays in the same place? This was a question that a early scientist Copernicus (1473-1543) thought about and and then Galileo Galilei (1564-1642) confirmed was the Earth that orbited the Sun. With this knowledge other scientists (we call them astronomers) worked out what Mercury orbited. What do you think?

Luke asked  “Do Saturn,Neptune or Venus orbit any planets other than the sun/orbit each other?”

A question I think that is linked to Seb’s. What evidence would you think would show that a planet orbited another planet? Think about the Moon, what does that orbit? Does it orbit the Sun? Supposing it did, what would you observe?  It was Galilei who built a telescope that would enable observations of the planets and therefore provide evidence which would answer the question. Like all science once the hypothesis has been made it can only become an accepted fact after relevant observation and production of evidence.

Luca asked “What is the furthest distance of a spaceship travel?” and “What is space made of?”

Luca, two great questions. For the first question I must admit I have no idea. From my visit to the Space Centre I know that NASA is planning to go to Mars. I see no reason why humankind will not be able, in the future, to leave the Solar System. We can already send satellites and other objects beyond the Solar System.

To your second question, the easy answer is ‘nothing’, other than stars, planets, asteroids, satellites and other bits an pieces. It does however contain what would be called ‘radiation’ of different types, otherwise we would not be able to see stars, the Moon or the Sun. Do you think it could contain anything else?

Interestingly, in Earth orbit, you would not be able to see any stars in space? Any ideas why?

Sammy asked “Can a black hole swallow Earth? If so when could this happen?”

Sammy, what do you think a black hole is? Why do you think it is called a black hole? I think it is something to do with that magical force called gravity. Think about gravity.  What does the gravitational force that an object has, depend upon?  Think about the force that pulls you to the ground. Think about the force that keeps the Earth in orbit around the Sun. Think about the force that holds the Moon in orbit. A black hole is a hole which light has been pulled into it, by a gravitational force. Think about a gravitational force that can pull light into it …….will it be able to swallow the Earth?

Sammy …something I didn’t know. It is thought that all galaxies have a black hole. Even our Milky Way galaxy has its own black hole.

A NASA photograph of a black hole. There is one…its a dot in the middle of the bright circle in the middle of the picture.

Bowen asked “Why do humans still think that there are resources on the moon? I think there are none.

A interesting question Bowen which I would like to challenge. Why do you think there are none? My thinking is that the Moon seems to be made of rocks and rocks are sources of all sorts of things. A lot of rocks contain silicon, what do we use silicon for? A lot of rocks (moon rocks included) contain aluminum which is used in a variety of ways, the rocks also contain hidden oxygen, a lot of rocks exist in the form of oxides (iron oxide is an example). Probably the biggest resource that the Moon has  is a low gravity. Any ideas why that is so important? Let me know.

Some Questions about the Solar System by Rishi, Ned, Maya, Thomas, Jackson, Adam and Pug.

Many thanks for the questions, and they are all about the Solar System. Amazingly I have just (three days ago) visited the Kennedy Space Centre in Orlando so they come at a time when I am excited by the science associated with space and space travel. I had questions before my visit and after it I had more. That’s the brilliance of these exhibitions, they raise questions. So let’s look at yours.

Rishi asked “How does the solar system work?”

I immediately think of why does it work in the way it does? The centre of the Solar System is the Sun. The Sun is one of a group of stellar objects called stars. Our star was named, by somebody, in the past, as the Sun.  Our star (the Sun) seemed to have attracted to it some massive lumps of matter/material which we call planets (planets are the biggest ‘lumps’ , the smaller ‘lumps’ are called asteroids and meteorites. What has given the Sun the ability to attract these ‘lumps’?

You then have the amazing thing that these lumps move around the Sun. They are attracted to the Sun but do not fall into it. They rotate around it, why do they do that? . Or does the Sun rotate around them?

So Rishi, your question is a great science question. From it lot’s of other questions arise, and that is what science is really about.

Ned asked “If the world split in half, would there still be a gravitational pull?”

Ned, thanks for the question. Gravity is one of those strange things called ‘forces’. Most forces are easy to define. You push things, you pull things by physically applying a force. Magnets  can push and pull so they can apply a force. So how can you explain the fact that things are somehow ‘pulled ‘ towards the Earth?  This seems to be something called a gravitational force. It’s strange. Nothing seems to be pulling or pushing you. Scientists have created a word called ‘gravity’ which describes the process of one object (of a big mass) pulling towards it a smaller mass.

We know that there is this force called gravity that exists. I am not sure that we have yet found out what causes it. We know that a very big object (of great mass) will attract a much smaller object (of smaller mass), however we have no idea why.

So at last to your question. My hypothesis (find out what that means). Slitting the world in half would mean that both halves of the Earth would move closer to the Sun because, the Sun is the biggest object in our Solar System.

Maya asked “What is the milky way?”

Maya, it’s a good question. I wonder who first used the name ‘the milky way’ and why? I firstly think about stars in the night sky, they produce white light (I wonder why – why not red or yellow light?). Does our star (the Sun) produce white or yellow light?

It is for a lot of us to really observe the night sky in all its glory. Why? It seems to be all the background light that we are experiencing when we look at the night sky. Go to a very dark place, away from the city, away from a near town and look at the night sky. You will see things you have never seen before. It is magical. You will see more stars than you have ever seen in your life. Only then will you see the Milky Way and only then will you know what it means.

Thomas asked “How many Suns are there in the universe”?

Thomas, thanks for the question. My first question is . What do you mean as Universe? As yet the investigation of the Universe in which we live is incomplete. We do not know how big it is. We do know, that the Universe consists of groups of stars that we have called Galaxies. We are in a Galaxy called the Milky Way (see Maya’s question). There are millions of stars in our Galaxy. So Thomas, in answer to your question ….we do not know …but the important thing is that you asked the question. By asking the question the quest and research for an answer continues. That is science.

Jackson asked “How big is Jupiter?

Jackson, a great question. It raised a question which I tried to find the answer to “Why do we want to know the size of Jupiter?’ I suspect it is to try to answer an even bigger question linked to Risha’s question. Why do the planets orbit the Sun? Is there some reason in there order of orbit …Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune?   Jupiter is the biggest planet in terms of mass and size in our Solar System . It would be nice if the size and mass of the planets and their orbital position was a straightforward order …but not so. That seems to be the outline of another question.

Adam asked  “How old is the Sun”

Adam, an interesting question, thanks.  It is thought that the Sun is 4.6 billion years old that is …would you believe it 4,600,000,000 years. Scientists reckon it was formed by the sudden compression of hydrogen and helium gas caused by the explosion of nearby star. Wow. This leads to lots of other questions …..think about them and let me know. The scientists also reckon that the Sun is about halfway through it’s life.

Pug asked “If all planets crashed into each other would it affect other Solar Systems?”

Pug, a good question. What do you think would happen if all the planets crashed into each other? How would it happen? Here is ia hypothesis. The most likely scenario would be the outer planets moving into a lower orbit and crashing into the lower orbit planets. They would then be affected by the gravitational pull of the Sun. They might then crash into the Sun. The Sun may therefore gain more energy and explode into a supernova. Pug, a hypothesis is an idea, can you come up with an alternative one? Let me know.

“How does a magnet become a magnet?” asks Ava (11)

A brilliant question Ava. I asked my team for their thoughts.

Yes team you are quite right there are some limitations to magnet making. The main one is that only certain metals can be made into magnets. These metals are called ferromagnetic metals.

Included in this group are the metal iron and the alloys of iron with the metals cobalt, nickel and some other rare earth elements .

It is thought that in these metals (including iron) have some electrons called ‘free electrons’ (not sure what an electron is, then go to Science Master Special – Atoms and Atomic Structure). It is these ‘free electrons’ that are involved in magnetism. In the alloys the  ‘free’ electrons align themselves with the magnetism of the external magnet, making a (for the alloys) a permanent magnet. For iron alone the magnetism is only temporary and you can test this in the experiment below.


Look at the short video I have made below. In the ferromagnetic metal (iron alloy) crystal domains you will see free electrons. In the metal these will be moving freely. As they begin to interact with the external magnetic field, they begin to align themselves, making a permanent magnet.












“Why does the sky go green when it hails?” asks Swifty (11)

What a question? Thanks  team for your thoughts. To me it seems to be a unique mixing of the colours from our sunlight. We know that the blue sky is because of the blue part of the spectrum of colour that comes from the white light from the Sun.

Some of the blue part of that spectrum of light is scattered when it hits the molecules of Oxygen and Nitrogen in Earth’s atmosphere. So blue coloured light illuminates the daytime sky. We know that when we see a sunset we can see a red sky in the distance and that is because we are looking at the Sun through a lot more atmosphere than we would do in a normal day. This is the dust that is in the atmosphere. In the experiment the milk acts as a ‘dust’ in the water.

I attach a NASA video that explains this then I will tell you my ideas about a green sky.

My thinking, and that of some others, is that the green sky is linked to the storm clouds (the background image above, was a pause in the hailstorm that the cyclists were experiencing). These were preventing some of the sunlight reaching the viewer who saw a yellow light mixed with the blue sunlight. the mixture of these lights could have caused the green light (a cyano type of light, like that below).

Very happy to hear comments and questions. Remember science development is about admitting your ignorance and my thoughts above are just thoughts. You and I need to do some further investigations.

Revised 10/1/18 to include experiment and colour example.

Siobhan (11) asks “Do fish sleep?”

Siobhan. You maybe interested in why all animals (ourselves included) sleep. It is in sleep that we make our memories. Our nervous system and brain work because of fantastic cells called neurons. When we feel something, it is the neurons in the nerve system of our hands that send messages to the brain about what we are feeling. When we sleep it is the neurons in our brain that link up and create the memory of that touching experience.

Thanks for the question. If you have any further questions you can make a comment or ask another question.
(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

“How do your eyes work?” asks Jeff (11)


I have tried to make the image below to show you how it works. The eye is complex and is made of lots of different things. For example it has it’s own sets of muscles which can stretch the lens and allow your eye to move. It is filled with a special fluid that allows light to pass through it and gives the whole eyeball a very ‘squashy’ feeling. It is also connected to the brain by something which we call the optic nerve. The optic nerve transfers the electrical signal created by the image to the brain.

You also have two eyes and one of them is more dominant than the other.

Try this little experiment.
Look at an object in the room and then hold a finger out in front of both of both of your eyes and look at the same object. Then close one eye while looking at the object, then open the closed eye and close the open eye. What happens to the object that you are looking at? For one of your eyes the object that you looked at did not move.That is the dominant eye.

Jeff you can make a comment or ask another question.

(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)

Andrew (11) asks “How do you make plasma?”

Andrew, quite an ‘exciting’ question. To find out how we make plasma lets look first at atoms and their structure. My team will do this and then I will come back to talk about plasma.

Andrew. I will be talking about a Neon atom. The Neon atom has 4 protons in its nucleus with 4 electrons orbiting it. Does that give you a clue to my plasma source?

The most familiar plasma sources that you might come across are Neon light tubes and lightning.

Firstly let us look at what plasma is. It is defined as a hot ionised gas which has an equal number of protons and electrons existing in the same space. Lets look at a neon light tube.

In the tube the Neon atoms lose electrons to the positive electrode, the remaining  Neon positively charged atoms (they have lost an electron) are attracted to the negative electrode. Lots of exchanges of electrons take place during this process and this ‘excites’ the electrons and creates the  plasma environment which gives of energy in terms of light.

Really hope that this helps. Please tell me if you do not understand bits of it or ask another question.

(Anyone reading this post who wants to ask a question or make a comment please feel free to do so)


Edited 11/10/2017 Pictorial representation in image changed to ‘drawing’. Text size on image changed.

“How many particles are there in the Earth?” asks Ravindra (11)

Wow what a difficult question. I will ask my friends to try and answer this question.

A ‘particle’ is a tiny bit of something. So Ravinder, well done, you have asked a question that I or my friends cannot answer. Try and ask some more.

Any reader can ask another question or leave a Comment in the Leave a Reply box below