Space : stars

     Stars:

    Stars have fascinated man for thousands of years, but astronomers only began to discover what the Universe really looked like when telescopes were invented. Our mother planet, Earth, is nothing more than a tiny speck of dust floating in a gigantic void called space. The stars that surround us give us the impression that the space is very full, however, they are at an incredible distance from us and each other. In general, space is as empty as it is vast, and far too vast to be conceivable. It would even take more than a million years to reach the nearest star, at the speed of a Concorde. In space, distances are so great that astronomers measure them in light-years.

>>A light year is the distance that light travels for a year, which is nearly 10 trillion kilometres. Thanks to modern telescopes, astronomers can now see stars and galaxies millions of light years away. 

Astromonia today!

    

    In a modern observatory, all the data recorded by the telescope are processed electronically to produce images that will highlight certain characteristics.

    

Close-up:

    Stars and galaxies seem tiny because they are very far away. The Carinæ Nebula is a colossal dust cloud that looks like a tiny red spot from Earth. Barely visible to the naked eye from the southern hemisphere, astronomers can study its smallest details with powerful telescopes. Deep in the center of the nebula, a star named Eta Carinæ is disintegrating. And since it takes 8,000 years for the light of the Carinæ nebula to reach us, these are images that show it as it was 8,000 years ago.

SCHMIDT British Telescope  

ANGLO-AUSTRALIAN Telescope

HUBBLE telescope

See the invisible !

    Astronomers use X-rays to see what is invisible to the human eye! The three images show the debris of a star that exploded in 1660. The ordinary telescope reveals an empty sample of the sky, but with radio telescopes and X-ray telescopes we discover a cloud of debris of several billion kilometers. Hot gases are projected into space at more than 6,000 km per second.

HUBBLE's view :

    The atmosphere of the Earth distorts the light of the stars, hence the difficulty of seeing them clearly. The Hubble Space Telescope circumvents this problem by navigating through space 595 km above Earth, out of the atmosphere. Hubble is the size of a bus; it orbits the Earth at 28,000 km/h. He can see galaxies that are billions of light years away, and he sees them as they were billions of years ago.

Unity is strength !

    Sometimes, several telescopes are combined to give a better view of a pale object. The opposite battery, in New Mexico (USA), consists of 27 huge satellite dishes that detect radio waves. A computer computes all the data into a single image. These concave parables work by returning radio waves to a central detector. Telescopes that detect light work the same way, but they are equipped with parabolic mirrors that reflect light.

The CELESTIAL twins :

    The Keck twin telescopes in Hawaii are the largest light-sensing telescopes in the world. They are located at the top of a volcano, far from the lights of the city. Here, the rarified and clear atmosphere is ideal for observing the low brightness of galaxies. Inside the Keck telescopes, the mirrors are made of separate sections that can change position, allowing astronomers to change the shape and size of the mirror to get a better view.