The golden record

Voyagers

Voyager 1 and 2 are two spacecraft that were launched in 1977. Both of them explored Jupiter and Saturn. Voyager 2 went on to explore Uranus and Neptune but Voyager 1 went off in a different direction. They sent us fantastic pictures from the Solar System. Now, more than 40 years old, both of them are still going and going and they have left the Solar System.

Voyager 1 and 2 contain a curious message aboard. It is a kind of time capsule, intended to communicate a story of our world to extraterrestrials. It is a golden disk with recorded sounds and images selected to show the diversity of life and culture on Earth to aliens, in case they exist and find out one of these spacecrafs.

All the contents were selected by Carl Sagan, a very famous astronomer, and his team. In the golden record there are 115 pictures from Earth and a variety of natural sounds like those made by wind and thunder, birds, whales and other animals. The added musical selections from different cultures and ages and spoken greetings from Earth people. 

Creating our own golden record

But everything was made more than forty years ago. Now we have new pictures from Earth, it is easy to look for them on Internet, and there are thousands of new songs to send to aliens. So, we are going to prepare a new golden disk, with new images, new songs and new greetings for new Voyagers. 

 You will have to choose one  picture from our world and justify your choice. You will select a song in English and sing a short part of it. Think about the best song you will send to extraterrestrial people. And finaly, write a greeting for them.  We will select the five best ones to include in our particular spacecraft. 

Terraforming Mars

Mars is the fourth planet in our solar system.  Its name comes from the Roman god of war.  Mars is also known as  the Red Planet because of its color, due to the presence  of rusty iron in the ground. It is a terrestrial planet, small and rocky. The planet gravity is 38% of Earth’s. Mars has big volcanoes; Olympus Mons is the highest volcano in the Solar System. But all of them are dead.  It also has lot of impact craters. Mars has two moons: Phobos and Deimos.

Mars (https://mars.nasa.gov/system/resources/detail_files/7808_global-color-views-mars-PIA00407-full2.jpg)

Mars has a thin atmosphere;  it is made of carbón dioxide, nitrogen and argon. It hasn’t got oxygen. So, human beings cannot breath there. The temperature is very cold; it ranges from -125 ºC to 15 ºC. In the past, it was warmer. Huge dust storms occur on Mars.

Mars had lots of liquid water in the past. Now water exists as ice in the poles and, perhaps, beneath the surface. On some martian places, there is evidence of liquid salty water in the ground, but these salts may be toxic for living beings. 

One day on Mars lasts 24.6 hours. It is just a little longer than a day on Earth. One year on Mars is 687 Earth days. It is almost twice as long as one year on Earth. Like our planet, Mars has seasons.

Scientists want to know if Mars may have had living things in the past. They also want to know if Mars could support life now or in the future. Some of them think that colonizing the Red Planet is essential for the future of humanity.

But if we want to live in Mars, we have to make the planet habitable. We have to terraform Mars. Terraforming is the use of technology to transform an inhospitable planet into a habitable one, with the Earth qualities needed to sustain human life. 

Terraforming Mars (Wikipedia)

To terraform Mars, scientists would have to change the atmosphere composition, to raise the level of greenhouse gasses in order to increase temperature, to raise the level of oxygen to breathe and to get liquid water. Can you help scientists to change Mars and make it habitable for human beings? What do you suggest?

References
https://spaceplace.nasa.gov/all-about-mars/en/
https://easyscienceforkids.com/all-about-mars/
https://schooledbyscience.com/terraform-mars-possible/

3D Mars: making anaglyphs

How does 3D work? 

3D (three-dimensional) means that an object has width, height, and depth. On the contrary, a 2D object does not have depth and thus is flat, just like a sheet of paper.
Because our eyes are spaced apart, each eye sees the same 2D view, but from a slightly different perspective. The brain puts the 2D image from each eye together, giving us a 3D view of the world. That is, we can perceive depth.

Making anaglyphs

We can create a 3D image by superimposing two 2D images. It is called anaglyph, and this picture simulate the way our eyes work. Making an anaglyph is so simple that anybody with a camera, computer equipped with photo-editing software, and a pair of tinted glasses can make their own 3-D pictures of Mars, family members, pets…
In an anaglyph, the same 2D picture is overlapped, but spaced slightly apart. One of the overlapped images is colored cyan, and one red. We can achieve this by using two cameras side by side, or only one and moving its position horizontally. With the help of the software Anaglyph Maker we will get our 3D pictures.
When we look an anaglyph with 3D glasses, the lenses only allow the red image to enter the left eye and the cyan image to enter the right eye. The visual cortex of our brain fuses the two images, and we perceive the image in 3D.

Making 3D glasses

Take the template, cut out the glasses, including the holes for the eyes. Cut one cyan-color cellophane and one red-color cellophane. The two pieces will cover the eyeholes in the glasses. Glue the cellophane on the inside of the glasses. Place the red cellphane on the left eye and the cyan cellophane on the right eye (left and right when the glasses are on our face).

XXII Solar Week: The Sundial Project

If you want to know what time it is, you probably watch at your wristwatch or mobile phone. But imagine that you live some centuries ago... Sundials are the oldests known instrument for telling the time. In fact, the earliest known sundial was made by Egyptians about 3.500 BC. As the Sun moves across the sky, the shadows objects cast move too. And people use this movement to know the time.

There are two parts in a sundial. One of them is called a gnomon; normally a stick that cast a shadow. The other one is a flat surface with marks, one for each hour of the day, where the shadow is projected. This is the dial plate. Those marks are usually numbered lines, the hour lines, that show the hours of the day. As the day passes, the gnomon' shadow moves around the dial; the shadow falls on a new line every hour.

Our Science Week is coming; and as every year, we are going to work about sundials. We are going to learn about these instruments, how they work, different types of sundials. And the most important... you are going to build your own sundial. Don't worry; it's very easy. Here you have some sundials made by students last year.

But, in my opinion, it is important to know about sundials in Granada too. How many sundials are there in Granada? Where are they? What kind of sundial is every one of them? Answer these questions as comments. Please, and if you can, take photos of those sundials. Send them to me and I will include your images in our blog.

And now, a very difficult question: where is the sundial of the picture below?

Recursos:

Construcción de relojes solares. Incluye la descripción de los principales tipos de relojes de sol así como plantillas de los cuadrantes solares para relojes orientados.

Algunos modelos de relojes solares.
Relojes solares otras semanas de la ciencia del IES Zaidín Vergeles.
La sombra del tiempo. Relojes solares del IES Zaidín Vergeles en el diario Granada Hoy.
Son muchas las páginas web dedicadas a la gnomónica y a la construcción de relojes solares. Algunas de las más representativas son:
Relojes de Sol de Mallorca.
Reloj andalusí. Web andaluza de relojes solares.
Relojes de Sol de la provincia de Málaga.
Asociación Amigos de los relojes de Sol.
North America Sundials Society.
Sundials on the Internet.

Growing microorganisms at our laboratory

In these days we are studying microorganisms in our classes. Bacteria are the most abundant living beings all over the planet and we can find them everywhere. Today we are going to confirm it. At our laboratory, we have prepared some Petri dishes with culture medium, and we have put different objects over it: our fingers, different plant leaves, our keys, ear rings... We have even sung a song to a Petri dish. Tomorrow we will see our results. If bacteria are everywhere, we will expect that our bacteria grow. In this case we will see lot of colonies of different sizes, colors and shapes. Perhaps we will have some fungi. I would like to know your opinion about our experiments. I know that some of you want to repeat these experiments at home. I have some Petri dishes for the best comments. 

Journey to the center of the Earth: Making crystals

The lava, porous in places, was covered with little round bulbs; crystals of opaque quartz, decorated with clear drops of glass, hung from the vaulted ceiling like chandeliers, and seemed to light up as we passed. It was as if the spirits of the underground were lighting up their palace to welcome their guests from the Earth.

‘It’s magnificent!’ I shouted in spite of myself. ‘What a sight, Uncle! Look at the colours in the lava which go from reddish-brown to bright yellow absolutely continuously. And these crystals that look like luminous globes!’

‘So you admire all that, my boy? You will see lots more, I hope.’

Jules Verne: Journey to the centre of the Earth

Crystals are a special kind of solid material where the molecules fit together in a repeating pattern. This pattern causes the material to form all sorts of unique shapes.

Crystals can have very flat surfaces called facets. They can form geometric shapes such as triangles, rectangles, and squares. The shapes are a direct result of the type of molecules and atoms that make up the crystal. Smaller crystals and larger crystals that were formed of the same molecules and in the same method should have similar shapes.

The process of crystal forming is called crystallization. Crystals often form in nature when liquids cool and start to harden. Certain molecules in the liquid gather together as they attempt to become stable. They do this in a uniform and repeating pattern that forms the crystal.

In nature, crystals can form when liquid rock, called magma, cools. If it cools slowly, then crystals may form. Many valuable crystals such as diamonds, rubies, and emeralds form this way. Another way crystals form is when water evaporates from a mixture. Salt crystals often form as salt water evaporates.

Can we make crystals? Of course. A good example is when saltwater is left to dry. The moisture will slowly evaporate and the only thing that is left is the salt. Salt appears in crystallized form.

Another example is to grow ammonium phosfate or copper sulphate crystals. Both of them are safe chemicals for producing a mass of crystals quickly. The first one is a white powder that yields clear crystals; the second one is a bluish power that forms beautiful dark blue crystals.

To get the crystals we have to stir salts into boiling water until the powder is completely dissolved. Put the solution into a container in a location where it will not be disturbed. If we want to get large crystals, let's try to cool the solution slowly from very hot down to room temperature. If we want big crystals we can take a small single crystal and place it in a new growing solution.

Good luck!!

And here, our first results. Beautiful crystals!

The great show in the winter sky

Look at the sky in these nights. You will see some of the most beautiful constellations with interesting objects as nebulas, star clusters and different types of stars.

Orion is a hunter, the lover of Artemis, goddess of the hunt. In this constellation you can see two of the brightest stars in the sky. Betelgeuse is a red supergiant that marks the hunter's shoulder, while Rigel is a blue supergiant star that marks the knee. Bellatrix, Orion's left shoulder, is a blue giant. Saiph serves as the hunter's right foot. There is a chain of three stars that mark his belt: Alnitak, Alnilam and Mintaka. Below of Alnitak there is a chain of stars and a visible nebula, Orion's nebula: all of them forms the hunter's sword. Other stars form the head and the shield.

Canis major, the greater dog, follows Orion through the sky. This constellation contains Sirius, the brightest star in the night sky and one of the closest stars to Earth, at a distance of 8.6 light-years.

Taurus represents the figure of a celestial bull charging towards Orion. The hed of the bull is the V-shaped star cluster named the Hyades; the brilliant red Aldebaran, an orange giant star, marks its eye. Taurus has one of the best known open clusters, with seven stars easily visible to the naked eye. This is the Pleiades, also named the Seven Sisters. They are the daughters of Atlas and Pleione in Greek mythology.

Try to see these constellations, discover the different stars. Are you able to watch the Pleiades star cluster? How many stars can you see in it? I am willing to read your comments.