The Birthplace of Stars.

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The birthplace of stars.

A molecular cloud is a vast area in space that is denser than its surroundings.

Eventually, gravity causes the cloud to collapse - this is where Protostars (young stars) begin to form.

As more matter accumulates in a certain area, it causes density, pressure, and temperature to rise. When a critical temperature of 15 million degrees Celsius is reached, nuclear fusion takes place, and a star is born.

By the time our local star, the Sun, formed completely, it had used up almost all the mass in its vicinity. The new Sun was surrounded by a spinning, swirling disc of leftover material called a solar nebula. Inside this flattened disc is where the planets, moons, asteroids and all the other celestial objects that orbit the Sun were constructed.

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Eyes are amazing and have a very long history.

Image credit. Kalea Jerielle on Unsplash.

For about 2 to 3 billion years primitive life forms on Earth had no way of detecting light, they had to live out their lives in complete darkness by using other sensors.

Then came simple eyespots or light receptors, now for the first time living things were able to detect some light.

We know that Trilobites had evolved compound eyes by studying their 550 million-year-old fossils. We still see compound eyes in the animal kingdom today.

From that first simple eyespots, we now see a wide diversity of complex eyes throughout the animal kingdom.

Over many thousands of generations, little evolutionary improvements were made to primitive eyes before some animals finally evolved complex camera-style eyes like the ones seeing this article.

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Have You A Good Imagination.

Image credit. John McArthur on Unsplash.

There are countless reasons why a plane could not leave the Earth and go on a long flight through space. But sometimes we need to use our imagination, this is one of that times.

It is difficult to comprehend the distances involved when we think of space journeys, even the Sun the closest star to the Earth is 149.6 million kilometres away.

For the fun of it, a Boeing 737 airliner travelling at normal cruising speed would take over 20 years to cover that distance between the Earth and the Sun.

Now send the plane to Sagittarius A* the black hole at the centre of our galaxy the Milky Way. That long journey from the Earth would take over 33 billion years. Yes, our galaxy is vast but it is minuscule in comparison to the size of the Universe.

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Our amazing life-giving water world.

Image credit. Jack Cook, Woods Hole Oceanographic Institution.

The total amount of water in the oceans, seas, lakes, ice caps, and the atmosphere is calculated at 1,386 million cubic kilometres, that number also includes water in the Earth's crust.

Over 96% is saltwater, and the small amount leftover is fresh water in the lakes, rivers, and atmosphere.

One cubic kilometre of water contains one trillion litres. We see flooding due to heavy rainfall in many parts of the world, not surprising when you realise that at any one time, the Earth's atmosphere could hold up to 13 thousand cubic kilometres of water.

Look at the scaled image above, that blue ball of water covers 71% of our planet's surface. Yes, considering the size of the Earth a very thin film of water covers most of its surface.

End of article.

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We can only imagine what our early ancestors were thinking as they gazed up at the night sky, were they curious as to what the heavens had to hide?

Now it is very different as we have developed sophisticated telescopes and other specialised scientific instruments that are helping to reveal some of the secrets the Universe holds.

You may enjoy reading some of my easy-to-understand articles regarding the Universe and Life.

Free reads.