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Speedy Experiment – Lemon Volcano20/08/2020

I can’t say I’m a big fan of lemons. They’re just like oranges, but a more boring colour and with a horrible taste. But, like them or hate them, with a few simple ingredients, you can turn them into a lemon volcano! You don’t need time or a laboratory for this one; like the tremendous teabag rocket, the test takes less than ten minutes. Furthermore, it uses entirely household materials, so won’t harm the environment!

You will need:

  • A lemon – mine was quite an old one, which was good as it stopped me from wasting food.
  • A spoon
  • A knife (get a grown-up’s help for this one!)
  • Bicarbonate of Soda
  • A spare container; the second ramekin (little dish) in my photograph has a dash of washing-up liquid under the recommendation of another experimenter; however, I found that I didn’t need this.

The method:

1) Cut the two ends off of the lemon with the knife.

2) Use the spoon to core out some of the middle.

This should make a “bowl” shape like the image above.

3) Squeeze out the lemon juice from the lemon-ends into the spare container.

4) Add some bicarbonate of soda to your lemon-bowl.

The lemon juice will react with the soda and create an eruption. If your reaction is underwhelming, add a little of your spare lemon juice…

If you like, try testing the lemon volcano method with other citrus fruit. Does it work with lime? Orange? Grapefruit?

The science:

Bicarbonate of soda contains carbon – it’s in the name (bicarbonate) . When the citric acid in lemon juice reacts with the soda, those carbon dixoide atoms gain two oxygen atom companions each, and become carbon dioxide. Carbon dioxide is a gas, so that creates bubbles in the juice-and-soda – and because quite a lot of it is being produced, the lemon seems to erupt!

Speedy Experiment – Alien Goo05/08/2020

Alien goo. What is it? Why do aliens use it? When did aliens discover it? I can’t answer any of those questions, because as far as we know, alien goo doesn’t exist. But I can tell you how to make something a lot like it! This goo will magically change form before your very eyes. You don’t need time or a laboratory for this one; like the tremendous teabag rocket, the test takes less than ten minutes. Furthermore, it uses entirely household materials, so won’t harm the environment!

WARNING: This is an extremely messy experiment, especially if there are any excited children involved. Make sure you’re wearing clothes you don’t mind getting stained!

The alien goo ingredients:

  • Some water
  • As much cornflour or cornstarch as you can acquire
  • Some food colouring – I used orange.
  • A bowl
  • A measuring jug
  • Some newspaper to cover any surfaces

The alien goo method:

1) Measure out some water – perhaps 100ml – and pour that into the bowl.

2) Dry the jug, then add four times that amount in cornflour to the water.

3) Add seven or eight drops of food colouring.

4) Mix it all together and let if flow!

“Alien goo” is… strange. You can pick it up like a solid, roll it up into balls and shapes, but the moment you suspend it in the air, it seems to “melt” like a liquid.

Be warned – siblings seek this stuff out like they can smell it. Perhaps they’re aliens too…

The alien goo science:

This “alien goo” is a “non-Newtonian fluid”. Isaac Newton, who calculated loads about gravity, made a “law”  – that’s a prediction about physics – that liquids will always behave in a certain way. But, naturally, we’ve discovered more since he lived 400 years ago. One of the things we’ve discovered is liquids that don’t follow that law he made – alien goo being one of them. And because they don’t do what Newton said, they’re non-Newton-ian fluids!

See Saturn (CosWatch Blog 8)24/07/2020

Welcome to the eighth of Fun Science‘s CosWatch blog posts, which you can read through with your young scientist and learn how to see Saturn.

What is CosWatch?

There’s so much to see in the night sky! You may have seen Brian Cox on TV describing the “wonders of the universe”, or Carl Sagan talking about the “awesome machinery of nature”, and they’re absolutely right. But while huge rockets and observatories can help, space isn’t just for people with expensive equipment. You can see amazing things from millions of miles away from your very own back garden. Each week, I’m going to talk about one of these incredible objects, and how you can find them.

This beautiful footage from Voyager 2 is a timelapse showing the probe’s approach to the Saturn.

This time, we’re going to be talking about how to see Saturn, the second-largest planet in the Solar System!

Tell me about Saturn

Saturn is the sixth planet from the Sun, and takes 29 years to orbit it. This makes sense; it’s further (and therefore has a greater distance to travel) than Jupiter, which takes 12 years, and much closer than Uranus, which takes 84 years. Like those two planets, it is a gas giant, meaning it is mostly made of gas. Also like those two, it has a short day of only ten hours and forty-two minutes.

“Saturn as seen from Mimas” by Chesley Bonestell is credited by some as inspiring the post-war appetite for space that fuelled the race to get the moon.

Saturn is most famous for its colossal rings. These rings aren’t solid objects as they may appear, but a collection of lots of tiny bits of ice, and a small amount of rocky material. These ice-lumps range from the scale of microns (smaller than a human hair) to metres (bigger than a car).

This image from NASA allows us to see Saturn in transit – that is to say, passing in front of the sun. This helps illustrate the size and majesty of its rings.

The Moons of Saturn

Some kids get all of the toys. As well as the biggest rings, Saturn has 82 moons, the most of any planet in our solar system. We discover them so quickly, only around 50 of them have names!

The most famous of these moons is Titan. Titan is a very exciting moon; much larger than ours, it’s the only other place in the solar system where we’ve found still bodies of liquid, which may be necessary for life. We’ve also landed a probe on its surface; the image to the right is really from the ground of Titan itself!

On the right, Titan from space. On the left, Titan from its surface.

There are of course many other moons of note. Pan, for instance, is shaped like a sherbert UFO sweetie. Methone, meanwhile, is shaped like a pebble.

On the left, the pebble shaped Methone. On the right, the sweetie-shaped Pan. Both from NASA.

Saturn has been observed since prehistoric times, and represents many different Gods in many different mythologies.

However, its rings and moons weren’t known about until much later. Galileo, who discovered four of Jupiter’s moons, observed Saturn in 1610. He thought the rings were two moons on either side of Saturn, and described them as “Saturn’s ears”; based on this sketch he drew, it’s easy to see why!

Phineas L. MacGuire Series | Book awards, Saturn, Children's books

How can I see Saturn?

As said, Saturn has been observed since ancient times, which means that it can easily be seen with the naked eye. Most modern telescopes will easily highlight the rings; if you’re lucky, you’ll see some moons too. You can buy special filters to observe more detail, but these aren’t necessary.

As ever, the website timeanddate.com is very helpful for this – using their “night sky” function, you can choose your location and planet, then simply test visibility for each of the nights. Currently, Saturn is hanging around “with” Jupiter in the South – though of course they’re over a billion miles apart in real life.

Saturn has inspired art, religion and scientific discovery for thousands of years, and will pretty much always be visible. I hope you enjoy observing it!

In conclusion:

  • Saturn is the magnificent sixth planet from the Sun, and the second gas giant.
  • It has huge rings made of tiny pieces of ice (and a little rock), and over 80 moons.
  • We have landed a probe on the surface of Titan, the largest of those moons.
  • Saturn has been observed since ancient times, but we only worked out it had rings about 400 years ago.
  • You can easily see Saturn with the naked eye, and its rings and moons with a telescope.

What’s next for CosWatch?

This is the last of the CosWatch blogs for now, but who knows what’s in store for the future? I hope you’ve been able to learn some interesting facts, and perhaps see some of these beautiful objects for yourself. I’ve been Electron Edward, and it has been a pleasure to share the delights of the cosmos with you.

Notes:

Fun Science recently created a “Planets and Space” home kit, pre-orderable now for only £5.00. Check it out here!

In this article I explain that a further a planet is from the Sun, the longer it takes, generally, to orbit it. This is briefly touching on Kepler’s laws of planetary motion; however, this is fairly complex maths, and you don’t need to focus on this until at least year 12.

Younger scientists, or older ones with good taste, may want to check out The Magic School Bus Lost in the Solar System in the (sadly late) Joanna Cole’s Magic School Bus series to help them remember and learn about the different planets – though note that this book has Pluto classified as a planet, which is of course out of date..

Speedy experiment – nervous coins22/07/2020

Your pocket money is alive! Well, sort of. Well, not really. But your coins will certainly seem alive after this experiment. You don’t need time or a laboratory for this one; like the tremendous teabag rocket, the test takes less than ten minutes. Furthermore, it uses entirely household materials, so won’t harm the environment!

You will need:

  • An old bottle – I used an old wine bottle; if your parents don’t have one of those about, you can use any any tall glass container
  • Coins – I tested two, but aim for multiple sizes (as long as one is large enough to cover the mouth of the bottle)
  • Some water
  • Access to a freezer

The method:

1) Remove the bottle cap, and place the empty bottle in the freezer.

2) While you’re waiting (at least five minutes), immerse your coins in water.

3) Remove the bottle from the freezer, and place one of the coins on top.

The coin should jump around and make strange clicking noises, like some sort of especially nervous robot. Try testing with other sizes of coin. Does it work if the coin doesn’t cover the entirety of the hole? What about with different coin materials? Do you have any coins from other countries that you could test?

The science:

As the helpful diagram below shows us, hot air rises.

Warm-Up: Why does hot air rise and cold air fall downward ...

On top of that, it also takes up a larger volume of space than cool air. This means that if you put cool air inside a container – for example, a recycled bottle – it will try to escape as it warms up.

When you take the uncapped bottle out of the freezer, the air inside the bottle begins to warm up, rising and expanding. The coin on top moves simply because the new larger air is pushing past it.

So, no, as far as we know, coins aren’t sentient. But they can jump about when air warms up behind them, and that is very fun to watch.

The BIG EXPERIMENT results!14/07/2020

You dunked. And you dunked. And you dunked, and dunked, and dunked…

In our big experiment, we asked young scientists and their parents across the country to dunk three types of branded biscuit. With this data, we’ve been able to work out which is the most dunkable. But who was the winner? Let’s take a look…

See Andromeda (CosWatch Blog 6)10/07/2020

Welcome to the sixth of Fun Science‘s CosWatch blog posts, which you can read through with your young scientist and learn how to see Andromeda, our galactic next-door neighbour.

What is CosWatch?

There’s so much to see in the night sky! You may have seen Brian Cox on TV describing the “wonders of the universe”, or Carl Sagan talking about the “awesome machinery of nature”, and they’re absolutely right. But while huge rockets and observatories can help, space isn’t just for people with expensive equipment. You can see amazing things from millions of miles away from your very own back garden. Each week, I’m going to talk about one of these incredible objects, and how you can find them.

Today we look for Andromeda, a place far distant from any of our other CosWatch blog focusses.

APOD provides us with this ethereal picture of Andromeda.

What is Andromeda?

We live in a galaxy – a collection of stars, usually in a disk shape – called the Milky Way. Andromeda is simply another such galaxy.

Though perhaps the most well-known galaxy other than our own, the Andromeda galaxy isn’t technically the closest; this is because the Milky Way and Andromeda both have “satellite” galaxies, a bit like the moons of a planet. It is, however, the largest galaxy in a big nest of galaxies of which we are a member; this is called the “local group”.

Andromeda is sometimes called “M31”. This means it is the 31st entry in something called the “Messier catalogue”. This is a list started by French Astronomer Charles Messier of fuzzy, difficult-to-identify objects in the night sky, including nebulae and star clusters. Andromeda’s satellites have similiar entries in the catalogue – M32, for instance.

The past and the future

Despite being larger, Andromeda is more like our galaxy’s little brother than older sister; it is ten billion years old, some three billion years younger than the Milky Way. It was formed from the collision of several protogalaxies, which you can think of as galaxy babies.

Andromeda was first recorded as being observed by human beings in 964 AD. However, it and other spiral galaxies were thought to be nebulae into the 1900s. There was a great debate by two scientists as to whether these “spiral nebulae” were just nebulae or “island universes”. It was settled when Edwin Hubble observed a flashing star, which he was able to use to measure the distance to Andromeda. It became quickly apparent that this object was further away than anything else we had observed, and was probably another galaxy.

An article by Ella Alderson provides this demonstration of a galactic collision.

The Milky Way and Andromeda are heading towards each other at over 68 miles a second – incredibly fast from our perspective, but for objects as big as galaxies, really rather slow. In about 4.5 billion years – when Earth will be twice as old – they will collide and combine into one galaxy, dubbed “Milkdromeda”. This may result in the solar system being ejected from the galaxies. Don’t panic, though; humans as we know them will be long-gone, and any still-existing lifeforms will probably be alright, as Earth will still orbit the Sun.

Visiting Andromeda

Since it was discovered to be another galaxy, Andromeda has featured in many science fiction stories. It is the main setting for the game Mass Effect: Andromeda, as well as the film Guardians of the Galaxy. It’s also the setting of Andromeda, a series by Star Trek creator Gene Roddenberry.

The game map of Mass Effect: Andromeda. The various locations of this game are no match to the actual population of Andromeda, which is estimated to have something like a trillion stars!

Unfortunately, in real life, we probably can’t visit Andromeda. The laws of physics seem to say that we can only travel as fast as the speed of light; even if we did manage to match light with a probe or space ship, it would still take us 2.537 million years to reach the place. Fortunately, there’s plenty we can learn about it from simply observing it in the sky.

How can I see Andromeda?

The Andromeda galaxy is the only galaxy visible with the naked eye, albeit on moonless nights; despite being so far away, the brightness of its collected stars makes it very powerful. It forms part of the conveniently named Andromeda constellation.

To find it in the night sky, you need to find the “Mirach” nearby; think of it like using a sign post to choose the right lane on the motorway.

This diagram from WikiHow eloquently demonstrates how to find Mirach (and thus Andromeda) between the Cassiopeia and Pegasus constellations.

Fortunately, Mirach doesn’t move erratically in the way the planets do (there’s a reason “planet” is Greek for “wanderer”), so you should always be able to find it in this spot. Just use a star chart (or website like timeanddate.com) to work out when those constellations will be visible in your area, and you’ll be set!

There are some benefits to observing Andromeda with a telescope. You may be able to see some of Andromeda’s twenty dwarf satellite galaxies. The image below was taken in 1899; imagine what you could do from your own garden with a whole century of technology on top!

In conclusion:

  • Andromeda is another galaxy, bigger than the Milky Way but younger.
  • It is the largest galaxy in our galactic “local group”.
  • Sometimes people call it “M31” because it is part of a record of space things called the “Messier catalogue”.
  • It has been observed since the 900s but was only determined to be another galaxy in the 20th century.
  • It will collide with the Milky Way in several billion years.
  • We probably can’t visit it, but we can certainly learn lots about it from observation.
  • It can be seen with the naked eye near the Cassiopeia and Pegasus nebulae.
  • Telescopes can reveal smaller galaxies next to it.

What’s next on CosWatch?

Next time, we’ll look at Comet NEOWISE, a rare Astronomical opportunity this month. Don’t miss it!

Notes:

Fun Science recently created a “Planets and Space” home kit, available now for only £5.00. Check it out here!

If your young scientist is interested, they may like to hear about blue-shifting. Because Andromeda is heading towards us, its light waves are being compressed, which makes them bluer; if it was moving away, they would be being stretched, making it appear redder. It’s quite well-explained in this gif shared on the Fun Science Twitter page.

See Uranus (CosWatch Blog 5)01/07/2020

Welcome to the second of Fun Science‘s CosWatch blog posts, which you can read through with your young scientist and learn how to see Uranus.

What is CosWatch?

There’s so much to see in the night sky! You may have seen Brian Cox on TV describing the “wonders of the universe”, or Carl Sagan talking about the “awesome machinery of nature”, and they’re absolutely right. But while huge rockets and observatories can help, space isn’t just for people with expensive equipment. You can see amazing things from millions of miles away from your very own back garden. Each week, I’m going to talk about one of these incredible objects, and how you can find them.

This beautiful shot from Voyager 2 captures Uranus’ colour… but that might be the least interesting thing about this mind-blowing planet.

This time, we’re going to be talking about how to see Uranus, the second-to-last planet in the solar system!

Tell me about Uranus

Uranus is the seventh planet from the Sun, and takes a staggering eighty-four years to go around it; for every “month” of Uranus’ year, seven years have passed on Earth! Like Jupiter, it is a gas giant, meaning  it is mostly made of gas. Also like Jupiter, it has a short day of only seventeen hours and fourteen minutes.

I love this art by Stefan Blaser, which shows us how an astronaut would see Uranus from the surface of its moon Umbriel.

There’s something absolutely fascinating about Uranus which makes it totally unique. If you look at art of photos which show Uranus’ rings, you’ll notice they seem to be upright, rather than sideways. There’s a delightful reason for this – the entire planet is sideways! Nobody is quite sure why Uranus is this way.  Research suggests that when the Solar System was forming, the early Uranus was hit by an object larger than Earth, which pushed it over.

Uranus: The Ringed Planet That Sits on its Side | Space

This more distant image of Uranus demonstrates its tilted axis, and some of its moons.

Uranus has at least 27 known moons, mostly named after Shakespearean characters such as Ophelia, Cressida, Margaret and Puck.

Discovery and name

Uranus is even more distant than the first six planets. It wasn’t even identified as a planet in ancient astronomy, only as a star. That changed in 1781, when William Herschel discovered it – from the city of Bath, no less. Not only that, but its orbit helped Astronomers realise that there must be an eighth planet – Neptune was discovered sixty years later!

William Herschel working at his telescope, from which he’ll see Uranus. His sister Caroline would go on to make many discoveries of her own.

Astronomers didn’t agree on a name for almost seventy years. Rather than continuing the trend of naming the planets after Greek/Roman Gods, Herschel wanted to name the planet “George’s Star”, or Georgium Sidus, after his King. People from other countries didn’t want a planet named after an English King, and called it other names. One of the more popular names was Herschel, after its discoverer.

Unfortunately for Herschel (but fortunately for people who like good names for planets), Astronomers eventually settled on “Uranus”, after the Greek god Ouranos. Now, many people mock Uranus’ name because “anus” is another word for bottom, but most agree it’s a better name than George’s Star.

How can I see Uranus?

Uranus is more difficult to see than the more well-known first six planets, which is why it wasn’t recognised by astronomers for so long. It can be seen with the naked eye on a moonless night, but you’re better off setting up a telescope or binoculars. It will appear as a blue-green smudge; if you’re lucky, you’ll see some moons too. You can buy special filters to make it more visible, but these aren’t necessary.

Uranus will spend all of 2020 “in” the constellation of Aries the ram. It’s being shy at the moment, spending a lot of time hiding under the horizon where you won’t be able to spot it. I like the website timeanddate.com for this – using their “night sky” function, you can choose your location and planet, then simply test visibility for each of the nights.

Sadly, Uranus has chosen to hide from us tonight – but will be visible soon!

Uranus is my favourite planet without life, and I can’t wait to observe it soon. Stargazing is the perfect lockdown activity. It’s relaxing, it’s best done far away from people other than your family/housemates, yet it connects you to everyone on Earth. I hope you enjoy it!

In conclusion:

  • Uranus is the unusual seventh planet from the Sun, and the third gas giant.
  • It is flipped onto its side, with vertical rings.
  • Uranus has 27 moons, mostly named after Shakespeare characters.
  • Uranus was discovered in the 1700s in Bath, and Astronomers argued over its name for nearly 100 years.
  • You can see Uranus with the naked eye if you’re lucky, or fairly easily with a telescope.

What’s next on CosWatch?

Next time, I’ll be talking about the Andromeda galaxy, the most distant and large object so far on CosWatch. See you soon!

Notes:

Fun Science recently created a “Planets and Space” home kit, pre-orderable now for only £5.00. Check it out here!

In this article I describe Uranus as a gas giant. In fact, along with Neptune, it is a special type of gas giant called an “ice giant”. All that means is that it has lots of gasses other than Hydrogen and Helium.

Younger scientists, or older ones with good taste, may want to check out The Magic School Bus Lost in the Solar System in Joanna Cole’s Magic School Bus series to help them remember and learn about the different planets – though note that this book has Pluto classified as a planet, which is of course out of date..

Forensic Fun: Fantastic Fingerprints!29/06/2020

BREAKING NEWS: There has been a crime at the Fun Science HQ. Chemical Cress has discovered that all of her delicious digestive cookies  for the Big Experiment have been eaten!

Clearly, some forensic investigation (detective talk for “collecting clues”) is required. This is the perfect time to whip out our Fantastic Fingerprints experiment.

You will need:

  • Two pieces of paper (preferably one scrap, to help the environment)
  • Some sellotape
  • A pencil

Collect your fingerprints:

1) Use your scrap paper to draw a filled square.

Pencils are made of graphite. When you draw something, you are pressing graphite molecules onto the paper.

 

2) Press the finger of your suspect into the square.

This process moves the graphite molecules from the paper onto the ridges and grooves of your finger.

You can even see the grooves and ridges of our glamorous model’s fingertips here.

3) Push that finger into a section of sellotape.

It’s easier to keep the amount of sellotape small – long tangled strips are annoying!

4) Press that sellotape section onto your clean piece of paper, and label it. This is your fingerprint!

This isn’t a particularly even or clear fingertip. Still, it should suffice as evidence.

Now you have a record of a fingerprint. Do this for all of your suspects, and you can compare this to fingerprints you collect at the scene of the crime to discover the culprit!

About fingerprints

Fingerprints are essentially unique to every human being. Investigators, such as police officers or detectives, collect them. This is because, by matching collected fingerprints to ones in a database, you easily identify someone who has handled an object or touched a surface.

Humans have recorded fingerprints since ancient times. That said, Historians think people probably didn’t realise that everyone had unique fingertips until Victorian times; In 1840, a Doctor wrote to the police, suggesting checking for fingerprints to investigate a murder.

In The Adventure of the Norwood Builder, a Sherlock Holmes story released in 1903, a fingerprint is the key piece of evidence that helps the detctive solve a crime. Fingerprints have been used in crime stories and real life forensic investigations ever since.

Moon Phases (CosWatch Blog 4)23/06/2020

Welcome to the second of Fun Science‘s CosWatch blog posts, which you can read through with your young scientist and learn the phases of the Moon.

What is CosWatch?

There’s so much to see in the night sky! You may have seen Brian Cox on TV describing the “wonders of the universe”, or Carl Sagan talking about the “awesome machinery of nature”, and they’re absolutely right. But while huge rockets and observatories can help, space isn’t just for people with expensive equipment. You can see amazing things from millions of miles away from your very own back garden. Each week, I’m going to talk about one of these incredible objects, and how you can find them.

This time, we’re going to be talking about the Moon, and why it changes shape!

This amazing shot from NASA shows the Moon creeping up behind some trees at the US National Arboretum in 2018. A large number of the Earth’s beings would have looked upon sights like this all through their evolution.

Tell me about the Moon

The Moon is the Earth’s only natural satellite. Satellites in nature are objects that orbit planets and minor planets. The Earth is a planet, which makes the Moon, which goes around the Earth, a natural satellite! It takes just under a month to orbit around the Earth, and it takes about 1.28 seconds for light reflected off of it to reach our planet.

It’s a solid, rocky mass, like the first four planets (Mercury, Venus, Earth and Mars). It does technically have an extremely thin atmosphere, but nothing substantial. Scientists believe the Moon may exist because an early version of Earth collided with a planet the size of Mars, and the remaining rocks formed into the Earth and the Moon. This is called the “Giant-impact hypothesis”, and has a fair bit of evidence. Scientists really developed results that suggests that the Moon may be much older than this, but this doesn’t necessarily contradict the “giant impact” idea.

This graph shows us roughly what scientists imagine might have happened.

Because The Moon is visible from Earth, it has been an object of fascination for human cultures since the dawn of civilization. The Moon has been described by various peoples and races as a female God, a male God, a rabbit, a Buffalo, and countless other unusual and interesting interpretations. This is probably because of the different colours of the Moon; the darker parts, or “Maria”, look like shapes compared to the brighter “Highland” parts. These areas aren’t actually any particularly different; “Maria” simply reflect a few percent less light, which makes them appear darker.

This lovely art from Matthew Meyer demonstrates how people – or rabbits! – may have seen likenesses of themselves or stories they’d heard in the Moon.

It is the only celestial body other than Earth that humans have  visited; between 1969 and 1972, twelve astronauts have walked on the moon, collecting samples and enjoying the reduced gravity; anything on the Moon weighs about six times less than on Earth. This is because the Moon is roughly six times smaller than the Earth.

[youtube https://www.youtube.com/watch?v=az9nFrnCK60&w=560&h=315]

Why does the Moon change shape?

The Moon is tidally locked with the Earth, which also means it is in “synchronous rotation”. What that means, simply, is it moves around the Earth just as fast as it turns on its axis. Or, even more simply, the same side is always facing the Earth.

However, the Moon also doesn’t produce its own light, and only reflects that of the Sun. That means that as it moves around the planet, the half of it that is lit by the Sun moves around but the actual Moon doesn’t. This is difficult to visualise, but this image shows it quite well.

There are eight “phases” of the Moon. They are either “waxing” phases, when it appears to be getting bigger, or “waning” ones, where it appears to be getting smaller.

Waxing or waning? Shape Appearance
New Moon This phase is barely visible, because no light can reach it!
Waxing Crescent

More about this image…

Quarter

(or “first quarter”)

More about this image…

Gibbous

More about this image…

Full Moon

More about this image…

Waning Gibbous

More about this image…

Quarter

(or “third quarter”)

More about this image…

Crescent

More about this image…

The Moon’s visibility, age, and regular changes make it one of the earliest clocks in the world. Early human beings would use it to keep track of time, just like the seasons of the Earth.

How can I see the Moon?

As you might imagine, it isn’t too difficult to spot the Moon when it isn’t in its “New Moon” phase. It is the brightest object in the night sky; in fact, it reflects so much of the Sun’s light it can be seen quite often in the day.

The speed of the Earth’s rotation relative to the Moon’s orbit means that it rises about fifty minutes later every evening.  Like the Sun, it rises in the East. As with Jupiter, your best course of action for working out when it will appear is using the National School Observatory‘s website; unlike Jupiter, you’re unlikely to mistake it for anything else!

In conclusion:

  • The Moon is Earth’s only large, long-term natural satellite.
  • It has been observed by humans since time immemorial, and the different-coloured areas (“Maria” and “Highlands”) look like shapes.
  • The Moon moves around the Earth as fast as it turns around, meaning the same “face” is always looking at us, and light moves around it, causing the different phases.
  • It can be seen easily with the naked eye, except during “New Moon” phases.

What’s next on CosWatch?

Next time, I’ll be talking about Uranus, the third gas giant, and the seventh planet in our Solar System. Somerset residents will be particularly interested in this one!

Notes:

Fun Science recently created a “Planets and Space” home kit, pre-orderable now for only £5.00. Check it out here!

See Orion’s Belt (CosWatch Blog 3)17/06/2020

Welcome to the third of Fun Science‘s CosWatch blog posts, which you can read through with your young scientist and learn how to see Orion’s Belt.

What is CosWatch?

There’s so much to see in the night sky! You may have seen Brian Cox on TV describing the “wonders of the universe”, or Carl Sagan talking about the “awesome machinery of nature”, and they’re absolutely right. But while huge rockets and observatories can help, space isn’t just for people with expensive equipment. You can see amazing things from millions of miles away from your very own back garden. Each week, I’m going to talk about one of these incredible objects, and how you can find them.

This lovely shot from Universe Today shows Orion’s Belt clearly – the three blue stars in a diagonal line in the middle.

Orion’s Belt is the focus this week. You’ll learn what this celestial location is, and learn how to see Orion’s Belt.

What is Orion’s Belt?

Orion’s Belt, sometimes titled “The Three Kings” or “The Three Sisters”. refers to three stars in the constellation of Orion. Constellations are shapes in the night sky, that ancient people compared to mythogical figures or pictures of stories. Constellations are specific to whiever planet you’re on, and don’t refer to an actual “thing” in space; the stars in Orion are millions of miles apart, and not “aligned”.

This drawing by Johaan Bayer demonstrates how Ancient Greeks interpreted their view of the stars, and this image from EarthSky.org shows how we see it today..

In mythology, Orion was a giant hunter. You can see in the image above how the Greeks might have intepreted the stars as reflecting his shape; certainly his right “arm” looks as if it’s holding an arrow, and the three stars do look a little like a belt on a dainty torso. Admittedly, it’s quite difficult to see it now, but perhaps the Greeks had better imaginations than us, without TV to distract them.

What is in Orion’s Belt?

Again, describing something as being “in” Orion is a bit misleading, as Orion only looks like a flat shape from our planet; as this video shows, it’s actually a complex 3D shape with something like 1000 light-years between the different “dots” of light.

[youtube https://www.youtube.com/watch?v=lD-5ZOipE48&w=560&h=315]

What I can do, however, is describe the different stars and objects that make up the “belt” of the constellation you can see.

I’ve labelled this image from the Hubble space telescope to help you identify the different stars.

1. Alnitak

Alnitak is actually a triple star system, three stars that orbit around each other. The three stars are blue super giants, far larger than the Sun.

A size comparison between one of the Alnitak stars and our Sun. The Sun is millions of times larger than the Earth – Alnitak is almost frighteningly colossal!

2. Alnilam

Alnilam is also a blue supergiant. Within the next million or so years, this star may explode as a supernova!

3. Mintaka

Like Alnitak, Mintaka is another system of three stars. Once again we have some blue supergiants; because these perform nuclear fusion more powerfully than the Sun, they “die” more quickly and become beautiful nebulae or supernova.

 

It’s a bit like that bit in Star Wars where there are two Suns. In this case, rather than orange and red star, the Mintaka system is made up of three blue supergiants, which are extremely hot and far bigger than the sun.

4. Orion nebula

The last part of Orion’s Belt to talk about is perhaps the most exciting. Just below Orion’s Belt is the Orion Nebula. A nebula is the gaseous remains of a star that has stopped necular fusion; the ghost of a star is a fun way to imagine it. In the Orion Nebula, there is a “Stellar Nursery”, where protostars (new, baby stars) are forming – about 750 of them. What’s more, many of them have “protoplanetary disks”, huge circles of dust and gas where planets like ours may be created. To put it another way, the Orion Nebula is pregnant with hundreds of new Solar Systems.

The video below shows what it might look like to travel through this beautiful nebula – though it’s travelling much faster than we think is physically possible.

[youtube https://www.youtube.com/watch?v=xCFg5udYbAg&w=560&h=315]

How can I see Orion’s Belt?

Orion’s Belt can be seen fairly easily if you look in the South West sky during the evening (or North West in the Southern Hemisphere). View with the naked eye for the bigger picture, or with a telescope to examine individual stars; unfortunately, they are simply too far away to see anything like planets or moons.

Trying to see Orion’s nebula is more complex. Nebulae are, as a rule, difficult or even impossible to see with the naked eye. For that reason, if you have a telescope, try aiming that at the Orion nebula. Once you’ve located it, increase magnification to get a better view, and try different filters to make it more vibrant.

The Orion Nebula as seen by Marian McGaffney.

However, while I can’t make any promises, some people have been able to observe the Orion Nebula without equipment – you’d just have to find an area with very low light pollution, on the night of a New Moon.

In conclusion:

  • Orion’s Belt consists of three stars in the Orion Constellation; a constellation is a shape made of stars viewed from Earth.
  • The three stars – Alnitak, Alnilam, and Mintaka – are blue supergiants.
  • Two of those supergiants are triple systems, with three stars orbiting each other. Thus, the three stars of Orion’s Belt are actually seven stars!
  • Just below the belt is the Orion Nebula, with hundreds of new Solar Systems being formed inside it.
  • Orion’s Belt is easily visible on clear nights in the South-East.
  • Seeing the Orion Nebula usually requires a telescope.

What’s next on CosWatch?

Next time, I’ll be talking about the Phases of the Moon, and why it appears to change shape. Have a good week!

Notes:

Fun Science recently created a “Planets and Space” home kit, pre-orderable now for only £5.00. Check it out here!