Life existence elsewhere it is not known exactly how

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Life Existence elsewhere - It is not known exactly how life began on our own planet. Therefore, we have no objective means of assessing the probability of life beginning elsewhere or the likelihood of the critical steps of evolution which may lead to intelligent beings. Micro Organisms found in Martian area (Vegetation on Mars). 1
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ASTRONOMY DSST 05Mar2012 Panspermia is the hypothesis that life exists throughout the Universe, distributed by meteoroids, asteroids and planetoids Telescopes: (Not a choice) The first telescope invented was refractive in 1608 invented by Hans Lippershey . First one developed for Astronomy was by Galileo . Refracting telescopes are like binoculars/magnifying glass, and use lenses. Reflecting telescopes use mirror(s). The first reflective telescope was built by Isaac Newton . Why is a reflective telescope better than a refractive telescope? Reflective Telescopes give sharper images when looking at a wide range of colors and at longer distances. The maximum useful magnification of a telescope with a lens or mirror diameter of 2.5 inches would be roughly 130x. As a general rule of thumb, the maximum useful magnification is between 50 and 60 times the diameter of the lens or mirror. There was a 1 size question: difference in magnification between a certain size lens to a certain size mirror. Question: A 20cm Reflective telescope is how many times the magnification than a 5 cm refractive telescope? Why are Radio Telescopes so physically large? The large size of the radio dish allows for the collection of more incoming radiation - This is important because of the extremely long wavelengths of radio waves. The light-gathering power (or light grasp) of an optical telescope is directly related to the square of the diameter (or aperture) of the objective lens or mirror. Note that the area of a circle is proportional to the square of the radius. A telescope with a lens which has a diameter three times that of another will have nine times the light-gathering power. Larger objectives gather more light, and more sensitive imaging equipment can produce better images from less light. Nearly all large research-grade astronomical telescopes are reflectors. Some reasons are: In a lens the entire volume of material has to be free of imperfection and inhomogeneities, whereas in a mirror, only one surface has to be perfectly polished. Light of different colors travels through a medium other than vacuum at different speeds. This causes chromatic aberration. Reflectors work in a wider spectrum of light since certain wavelengths are absorbed when passing through glass elements like those found in a refractor or catadioptric. There are technical difficulties involved in manufacturing and manipulating large-aperture lenses. One of them is that all real materials sag in gravity. A lens can only be held by its perimeter. A mirror, on the other hand, can be supported by the whole side opposite to its reflecting face.
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