Back to the Moon for fresh perspectives

Perspectives on the Moon
I thought we could head back to the Moon for an updated visit and marvel at our first off-world landing site.

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We see it in our skies regularly and we forget what a momentous achievement it was for humanity to land on the Moon. As exciting as the planned Mars missions are, there is still so much to learn about our nearest neighbour.

Did you know?

  • The Moon was probably formed when an object about the size of Mars collided with the Earth a long time ago. The debris from that collision formed what we now know as the Moon.
  • Our rocky satellite orbits the Earth at a distance of roughly 384 thousand kilometers.
  • It takes the Moon about 27 days to orbit the Earth. This is also about the length of a lunar day so we only ever see one side of the Moon from Earth.
  • It has a very weak atmosphere called an exosphere. It is not enough to support human life so visitors to the Moon need to wear spacesuits.
  • The Moon’s gravity is about 0.16 of the Earth’s gravity so objects on the lunar surface weigh about a sixteenth of what they would weigh on Earth.

There are many more facts about the Moon on the NASA page titled “Earth’s Moon – In Depth”.

The first Moon landing

The Apollo 11 Prime Crew

Humans first landed on the Moon on 20 April 21 July 1969. The astronauts who took part in the Apollo 11 mission were Neil Armstrong, Michael Collins and Buzz Aldrin.

The mission to the Moon captivated the world. You can get a sense of how people must have felt as the astronauts headed to the Moon and eventually landed on the lunar surface from this CBS footage of that momentous day:

We’re so accustomed to seeing high quality images and video footage of modern space exploration that it’s easy to forget that the technology back then was not nearly as advanced. We’ve certainly come a long way since then.

Aldrin Next to Solar Wind Experiment

What does the Moon look like?

Thanks to NASA’s Lunar Reconnaissance Orbiter mission, we have some incredible footage. Here are two videos of both hemispheres of the Moon, including the side we don’t see from Earth.

This video footage shows the Moon’s position throughout 2017 with a lot of useful data that includes the Sun’s relative position, the Earth’s relative position and the phases of the Moon in tremendous detail.

The Moon’s Northern Hemisphere

The Moon’s Southern Hemisphere

A virtual tour of the Moon

Have you ever wondered what all those features of our rocky satellite are? Here is a terrific tour of the Moon from NASA:

Blue Marble

One of my favourite views from the Apollo missions is this iconic photograph of our home. It was taken by the Apollo 17 crew on their way to the Moon and it’s titled “Blue Marble”:

The Blue Marble

There is so much more for us to explore in our solar system. At the same time, we know so little about our own planet and have a lot of work to do to preserve it for new generations of explorers.

Header image credit: NASA Goddard Space Flight Center, licensed CC BY 2.0

Slo-Mo Popcorn

I came across this fantastic video of popping corn in slow motion from Warped Perception and had to share it with you.

So, how does popcorn actually pop?

First of all, there are a few types of corn that are grown. But only one kind can be popped. Popcorn.

And the reason that popcorn can be popped is that the outer layer, the hull, is thicker than any other type of corn. This comes in handy when the kernel is heated up.

You see, each kernel of corn has a small amount of water inside as well as a little blob of starch. When the water is heated up it turns into steam.  Super heated steam. The steam mixes with the starch and changes it into a gel like substance.

Now the steam continues to heat up and expand, this causes pressure on the hull of the corn kernel. Since the popcorn hull is thick, it contains the heat for a slightly longer time than other corn, giving the starch time to form into that gel like substance.

Once the pressure gets too high, the hull bursts open and the starchy gel expands outwards, cooling as it goes, forming the puffy, yummy substance we love to eat.

Fun Facts

  • Popcorn can jump up to 3 feet/1 meter into the air.
  • There are two types of popped popcorn, Snowflake and Mushroom shaped.

 

  • The oldest ear of popcorn was found in a bat cave in Mexico in 1948. It is believed to be over 5,000 years old.
  • A kernel will pop when it reaches a temperature of 175 degrees Celsius.
  • Popping popcorn is one of the most popular uses for microwaves.

The Biodiversity Heritage Library

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The Biodiversity Heritage Library has a wonderful collection of resources about our shared biodiversity online. What is “biodiversity”? Wikipedia explains it as follows:

Biodiversity, a contraction of “biological diversity,” generally refers to the variety and variability of life on Earth. One of the most widely used definitions defines it in terms of the variability within species, between species and between ecosystems. It is a measure of the variety of organisms present in different ecosystems.

The goal of the Biodiversity Heritage Library is to improve “research methodology by collaboratively making biodiversity literature openly available to the world as part of a global biodiversity community”.

A Sperm Whale

It is a remarkable resource, especially for school projects and for all you science geeks. One of the best parts of the Library is its extensive Flickr collection which has an enormous collection of scans and imagery.

The Library “serves as the foundational literature component of the Encyclopedia of Life” which you can find here. What is the Encyclopedia of Life?

Our knowledge of the many life-forms on Earth – of animals, plants, fungi, protists and bacteria – is scattered around the world in books, journals, databases, websites, specimen collections, and in the minds of people everywhere. Imagine what it would mean if this information could be gathered together and made available to everyone – anywhere – at a moment’s notice.

Its mission:

To increase awareness and understanding of living nature through an Encyclopedia of Life that gathers, generates, and shares knowledge in an open, freely accessible and trusted digital resource.

Between the Library and the EOL, these are wonderful biodiversity resources. Definitely worth bookmarking for all those school projects and personal exploration. I’ve added both sites to our Sources page.

Image credit: Biodiversity Heritage Library

Seeing our planet from the International Space Station

Our planet from the space station
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NASA publishes a large collection of photos and videos of our planet as seen from the International Space Station. They offer a truly spectacular view of our home.

What really stands out, particularly when you watch the videos, is that you don’t see borders and the many differences that divide us. Instead, what you see is the one, beautiful planet that we all share.

A wonderful example of this is astronaut Jeff Williams’ video of the Earth as he passed overhead during a recent visit to the International Space Station. This video, titled “Jeff’s Earth” is mesmerizing on a big HD TV:

This 2012 video titled “Earth Illuminated: ISS Time-lapse Photography” is another wonderful opportunity to see what the astronauts see from the ISS as they orbit the Earth:

It is easy to forget that the Earth is the only home we have and that we share it. Fortunately, photos and videos from organisations like NASA help remind us of what we have in common.

Here are some photos from the NASA Johnson Space Center collection on Flickr:

Featured image credit: NASA Johnson Space Center

Unbreakable Prince Rupert’s Drops

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I came across these awesome glass drops in a video by Destin Sandlin from Smarter Every Day.

When you drop a piece of molten glass into cold water, the result is a tadpole shaped piece of extremely hard glass.

Three Prince Albert drops
Prince Rupert’s drops

Well, at least the head of the drop is very strong. The tail is actually quite delicate.

A shattering Prince Albert drop
A shattering Prince Rupert’s drop

The reason Prince Rupert’s Drops are so strong is that the outer layer of glass hardens almost straight away, while the inside takes a bit longer. When hot glass cools down (and this happens with water turning into ice too), the glass shrinks. This means that the inside of the glass drop is cooling down and shrinking but the outside is already cold and hard so the glass pulls towards the centre of the drop and makes it really, really strong inside.

Before we look at a really cool video of Destin from Smarter Every Day trying to break one of these drops using a bullet, take a look at his video that shows you how the drop is formed.

Right, now you have seen how the drop is formed and that hitting it on the head with a hammer won’t break it but if you nip the tail then the whole thing explodes.

Destin takes it a step further and shows us that even a speeding bullet won’t actually break the head of the drop itself.

Tip: try watch this on a large, high resolution screen for an even better experience.

How cool was that?!

Will a bowling ball fall faster than a feather?

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If you dropped a feather and a bowling ball at the same time, which would hit the ground first? You would probably say that the bowling ball would hit the ground first, right? After all, a bowling ball is so much heavier.

It turns out that the relative weight of the objects doesn’t make a difference to which object will hit the ground first, as strange as that may sound.

One of the parents in our class chat group shared this terrific video from the BBC that explains what really makes a difference and, surprisingly, that a bowling ball and a feather will hit the ground at the same time under the right conditions:

So, as you can see, the factor that makes the difference in normal conditions isn’t the objects’ weight, it’s air resistance! When you remove the air, both objects fall at the same rate and hit the ground at the same time.

Image credit: Pixabay

One-stop guide to our Solar System

Solar System
I just came across NASA’s terrific one-stop guide to our Solar System and wanted to share it with you quickly. It’s a great quick reference with links to more in-depth materials. Click on the graphic below to get started:

Solar System - the 8 planets

Featured image credit: Kira, 5th Grade, Palm Crest Elementary, La Canada, Calif (17 July 2003) – sourced from NASA.

What happens when lightning strikes an airplane?

This morning our daughter asked me what happens when lightning strikes an airplane. She is a little afraid of storms and she was concerned about the passengers of airplanes when there are lightning strikes.

Understanding lightning better

Lightning is, at the same time, an awesome and terrifying phenomenon. It seems to affect us on a very primal level. Understanding it better helps us appreciate its awesome beauty while making sure we are safer during lightning storms. I found a great video from SciShow Kids about lightning:

National Geographic also has a great video that explains lightning:

Lightning moves pretty quickly so we don’t always see lightning in more detail. I found this terrific video on Wikipedia (your browser may not play the video if it doesn’t support .ogv formats):

So what happens when lightning strikes an airplane?

The prospect of lightning striking an airplane can be scary. I was fascinated to learn that planes are engineered to handle lightning strikes in an interesting way. Here is a video from the Smithsonian Channel:

If you are interested in reading more about how airplanes are engineered to withstand lightning strikes, also read an article on Scientific American titled “What happens when lightning strikes an airplane?”. Here is an extract from the Scientific American article that answer my daughter’s questions about passengers’ experience of a lightning strike:

Although passengers and crew may see a flash and hear a loud noise if lightning strikes their plane, nothing serious should happen because of the careful lightning protection engineered into the aircraft and its sensitive components. Initially, the lightning will attach to an extremity such as the nose or wing tip. The airplane then flies through the lightning flash, which reattaches itself to the fuselage at other locations while the airplane is in the electric “circuit” between the cloud regions of opposite polarity. The current will travel through the conductive exterior skin and structures of the aircraft and exit off some other extremity, such as the tail. Pilots occasionally report temporary flickering of lights or short-lived interference with instruments.

Thunderstorms are impressive and powerful natural phenomenon and it’s usually a good idea to keep your distance, regardless of your mode of travel. At the same time, it is good to know what even when you are suspended in the air, traveling through a storm, you are probably safe.

Featured image credit: Pixabay

Better storm prediction by knowing more about raindrops

The GPM satellite studying raindrops
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Did you know that knowing the size of raindrops in clouds can help meteorologists more accurately predict rainfall? A new joint American and Japanese mission promises to help scientists make even more accurate predictions based on the size of the raindrops in clouds. This next video is a great overview of the mission:

According to NASA’s Goddard Media Studios blog post titled “GMS: Why Do Raindrop Sizes Matter In Storms?”:

Not all raindrops are created equal. The size of falling raindrops depends on several factors, including where the cloud producing the drops is located on the globe and where the drops originate in the cloud. For the first time, scientists have three-dimensional snapshots of raindrops and snowflakes around the world from space, thanks to the joint NASA and Japan Aerospace Exploration Agency Global Precipitation Measurement (GPM) mission. With the new global data on raindrop and snowflake sizes this mission provides, scientists can improve rainfall estimates from satellite data and in numerical weather forecast models, helping us better understand and prepare for extreme weather events.

If you are curious about the spacecraft that is conducting this amazing survey work, here is a helpful explanatory diagram:

The GPM spacecraft

Here is a great video that explains how the size of raindrops can help better understand storm behaviour:

A transcript of the video is here.

NASA also published a great comic for kids about the mission titled “Raindrop Tales – GPM Meets Mizu-Chan” which you can download and print or read online.

NASA’s GPM mission site has a wonderful collection of videos, images and other information about the mission. Another great video is this one titled “NASA | GPM: One Year of Storms”:

This is a fascinating mission. I didn’t realise just how much storm prediction can be improved by understanding how big raindrops are.