Astronomy

The Hubble Space Telescope

The Hubble Space Telescope

He Hubble Space Telescope You can obtain quality astronomical images without the limitations imposed by the Earth's atmosphere.

The Hubble Space Telescope (HST) is located on the outer edges of the atmosphere, in a circular orbit around the Earth at 593 kilometers above sea level, which takes between 96 and 97 minutes

Hubble was put into orbit on April 24, 1990 as a joint project of NASA and the European Space Agency (ESA). The telescope can obtain optical resolutions greater than 0.1 second arc. It has a total weight of around 11,000 kilos. It is cylindrical in shape, with a length of 13.2 m and a maximum diameter of 4.2 meters.

The Hubble telescope is reflector and has two mirrors, the main one having 2.4 meters in diameter. For the exploration of the sky, it incorporates several spectrometers and three cameras, one with a narrow field to photograph small areas of space (of weak brightness due to its distance), another with a wide field to obtain images of planets and a third infrared.

Through two solar panels, it generates electricity with which it feeds the cameras, the four motors used to orient and stabilize the telescope, and the cooling equipment of the infrared camera and the spectrometer, which work at -180 ° C.

Since its launch, the telescope has received several visits from astronauts to correct various operating errors and install additional equipment. Due to the friction with the atmosphere (very tenuous at that height), the telescope is losing weight very slowly, gaining speed, so that each time it is visited, the space shuttle has to push it to a slightly higher orbit.

The advantage of having a telescope beyond the atmosphere is mainly that it absorbs certain wavelengths of the electromagnetic radiation that falls on the Earth, especially in the infrared, which obscures the images obtained, reducing their quality and limiting the range , or resolution, of ground telescopes.

In addition, ground-based telescopes are also affected by meteorological factors, such as the presence of clouds, and light pollution caused by large urban settlements, which reduces the chances of location of terrestrial telescopes.

Since it was put into orbit in 1990 to circumvent the distortion of the atmosphere (historically, the problem of all terrestrial telescopes), the Hubble Space Telescope has allowed scientists to see the Universe with more details and clarity never achieved.

Thanks to the observations made with Hubble, astronomers confirmed the existence of black holes, clarified ideas about the birth of the Universe in a big explosion, the Big Bang, which occurred about 13.7 billion years ago, and revealed new galaxies and systems in the most hidden corners of the cosmos. Hubble also helped scientists establish that the solar system is much younger than the Universe.

In principle it was thought to bring the telescope back to Earth every five years for maintenance and, in addition, to send a maintenance mission in space at each time. Subsequently, seeing the complications and risks involved in having it returned to Earth and launching it again, it was decided that there would be a maintenance mission in space every three years, with the first scheduled for December 1993.

Shortly after being launched, it was discovered that Hubble suffered from an optical aberration due to a construction error. Those responsible began counting the days for this first maintenance mission, hoping that the error in the optics could be corrected. The day arrived and the aberration was repaired satisfactorily.

Since in that first maintenance mission a system was installed to correct the telescope's optics, sacrificing an instrument (the fast photometer), Hubble has proved to be an instrument without equal, capable of making observations that continually impact our ideas About the Universe

Hubble has provided dramatic images of the collision of Comet Shoemaker-Levy 9 with the planet Jupiter in 1994, as well as evidence of the existence of planets orbiting other stars. Some of the observations that have led to the current model of the expanding universe were obtained with this telescope. The theory that most galaxies house a black hole in their nucleus has been confirmed by Hubble observations.

In December 1995, the Hubble Space Telescope photographed the Hubble deep field, a region about thirty millionth of the area of ​​the sky that contains several thousand galaxies. A similar image of the southern hemisphere was taken in 1998, with notable similarities between them, which has reinforced the principle that the structure of the Universe is independent of the direction in which it is viewed.

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