“Will we ever discover aliens?” asks Frank (9)

Frank, as my team suggested, in 2009 NASA’s Kepler telescope began pointing at a small patch of sky for four years. In that time it found a series of stars with Earth like planets surrounding them. If you multiply this little bit of the sky to cover the whole Universe you are talking about over 50 billion Earth like planets. A good assumption would be that some form of life found it’s way to existence on some of them. Maybe they have yet to develop, like us, a way of communicating over the great distances involved.

If you are a teacher read the following Guardian article Updated 26/02/2017

Shabaar (9) asked “Can humans cause an ice age?”

The last ice age ended about 11,700 years ago. It started almost 3 million years before that and was thought to have been caused by changes in the way that the Earth moved around the Sun.

So can we cause a new ice age? From this evidence it seems unlikely that we (humans) can cause a future ice age. With our production of greenhouse gases (Carbon Dioxide, Carbon Fluoride compounds and other related gases) it likely that we will be warming the atmosphere rather than making it colder. This may cause weather extremes which might make life on our planet (for humans) unacceptable. See the following link

Science Master Special – What might plants need to grow?

1. Air (Oxygen and Carbon Dioxide)
2. The Sun or some light or maybe some darkness.
3. Warmth (heat), or maybe some coolness.
4. Water (moisture, dampness)
5. Soil, rocks, compost, sand.
6. Time, lots or maybe little.
7. Creatures, in or above the soil. These could be giant worms or miniscule creatures.
8. Plant food. Fertilisers, minerals.

 

This list was helped by The Nuffield Space Project P77

Jessica(8) asked several great questions about the Solar System

Jessica. I have asked my team to answer the information based questions. I will try to help you with the other questions.

Jessica asked about Dwarf planets, the temperature of the Sun, The Earth’s layers and the size of Jupiter. Here are the comments from my team.

solarsystem1solarsystem2

 

I was interested in your question about Venus having an opposite spin to that of Earth. Earth has (if you are above the North Pole) a Counter (Anti) Clockwise spin while Venus (if you are above Venus’s North Pole)has a Clockwise spin. Most of the other planets spin in the same direction as the Earth. Here is a little experiment…..

Pick up a pencil and holding it upright begin turning it in a clockwise direction,  now still turning the pencil, turn the pencil through 180 degrees. Which way is the pencil now rotating, clockwise or anti clockwise?  It is thought that close to the beginning of the Solar System a close encounter with another large object caused the axis of Venus to move through 180 degrees. Is that a theory or a hypothesis?

To your question about the position of Mercury – I have no idea why it is the nearest planet to the Sun. At the beginning of the Solar System you have the Sun surrounded by orbiting space dust. This dust slowly collects together and the planets begin to be formed. The closest ring of dust to the Sun formed the closest planet (Which we call Mercury).

‘How many volcanoes can go off at once’ is Charlotte’s (9) question

Charlotte it might be worth reminding ourselves of what is a volcano, and why do they occur. I’ll let my friends start the discussion.

volcanoes

Some interesting thoughts team but we have to look at Charlotte’s question.’How many volcanoes can go of at once?’ Firstly there are recorded to be 1500 volcanoes in the world as we know it. There are also lots of volcanoes under the sea but we don’t know how many. Of the 1500 about 500 have been active over the last 100 years. So Charlotte,  it is quite difficult to give you a definitive answer. For a volcano to erupt there needs to be some activity in the magma (the molten core of our Earth) and maybe the tectonic plates (the mantel plates that make up the surface of our Earth). Where the plates meet there is lots of tension, this normally causes earthquakes (New Zealand) but could allow magma to escape via a volcano.

Mitchell (10) asked ‘What would happen if the Earth stopped spinning’

stopspin-copy

A great question Mitchell. Can you think of any other thing that might happen?

Firstly the speed at which the spin happens is measured at the equator. Any idea at what the speed would be at the North and south poles? If the Earth suddenly stopped spinning what would be the effect at the poles?

How long will each day and night be? Remember although it is not spinning it would still be orbiting the Sun.

Interestingly, because of the Earth’s spin the Earth has a bulge around its equator.  Remove the spin and the Earth will become a true sphere. This will however cause a redistribution of the Earth’s oceans. The world after the spin will look a little bit like it is depicted in the video below, a big continent in the equatorial area with an ocean either side of it.

Another thing that will happen is that the Earth will lose it’s magnetic field. No longer will you be able to hold a compass and see the pointer pointing to the north pole.

“What is the earth made out of” – asks Ruby (8)

Ruby, many thanks for the question. Now let’s think about what it means. Does it mean the ‘earth’, like the soil that we have around us OR does it mean the ‘Earth’, the planet that we are living on. I say on my front page  that science is all about asking questions, but asking them is not always an easy task, so well done you. I shall get my friends to try and answer the ‘earth’ question and I shall then give you an answer to the ‘Earth’ question. We might even find something for you to do!

earth-or-earth

 

So maybe you could find out something about how easy it is to break a rock up? How about making a small collection of some rocks. They are quite easy to find at Garden Centres, or on walks in the country, or on a stony beaches. Collect some and then try to scratch them. Can some rocks scratch other rocks? If they can which is the hardest? try to draw a picture of your hardest rock. It is most likely that it will be the softest rock in your collection that you will find in your ‘earth’.

Now Ruby let us look at the ‘Earth’ and the wonderful structure that you are standing on. This is where your rocks have come from.

I have built this small animated picture to show you the amazing ‘inside’, structure of the Earth.

Sheereen asks – “Where do the items that a black hole suck up, go to?”

Sheereen, I was always told that a Black Hole was a place where my money or lost items apparently disappeared without trace. But I think your question deserves a different answer. I asked my friends about it. I shall also ask them to avoid science fiction stories where Black Holes seem to be used in a variety of stories. Do Black Holes really exist I might ask?

blackhole

My friends are right. The denser (more compact) the mass (think about mass and weight) of an object the greater its gravitational pull. So when the Sun collapses into itself you have a object that gets very small and very, very dense so it’s gravitational pull increases and it begins to pull everything in towards it. when something is pulled into it (including light) where it goes to is a mystery. It may add to the mass of the collapsed Sun and make a stronger black hole by increasing the gravitational pull. OR as the Science Fiction writers would suggest it takes you to a new dimension. Thank you for your question Sheereen.

Walter Jr. (Grade 2) asks “I’ve heard the Sun revolves around the Earth, but I’ve also heard that the Earth revolves around the Sun. Which one really happens and how do we know?”

change-mind

My turn now. The astronomers at that time had noticed some strange behaviour when they were looking at the planets. For example, when they looked closely ( over many days) at the the path that Mars was taking in the night sky they were surprised to find that it suddenly started going backwards for a short time before continuing on a forward path. It did what astronomers call a ‘retrograde loop’ .  This could not be explained by a model where the Earth was the centre of the Universe with everything orbiting around it. It could however be explained if the Sun was the centre of our small universe(Solar System) and the Earth and the rest of the planets orbited it. The retrograde loop observation is then explained by the different orbits that each planet makes around the Sun. See an example in this link.

Ernie(13) asks -“What is at the centre of a black hole? What would happen if you fell into one?”

black-holes

We obviously know something about gravity. We know that it is a force that is generated by the mass of an object. The bigger the mass the bigger the force that it exerts on other objects. So we feel the force of Earth’s gravity on us and the Earth feels the force of the  Sun’s gravity on it. The Sun’s gravitational force keeps the Earth on an orbit around it. If it didn’t exist the Earth and all the other planets would start wandering in space.

Black holes are thought to be a source of a massive gravitational force, because of their mass , which is constantly increasing, and they don’t just pull other matter to them they pull light in as well …thus a black hole. No light – darkness.

So to your question.  I think you could now answer that yourself.