Telescopes_in_Astronomy

Telescopes in Astronomy SCI151 October 08, 2012 Telescopes in Astronomy Telescopes were thought to be created in the year 1608; the earliest known refracting telescopes were created using a tube with a convex objective lens with a concave eyepiece. These devices were designed to assist users in gaining a better view of things that were further away. Initially they were primarily used aboard sea going vessels it was eventually found that they can also view things such as the moon, stars and anything in the heavens much more closely. Unfortunately back in the early 17th century the telescopes were not that powerful and it was not until the mid 17th century that more powerful telescopes were being built. Later astronomers realized that if you build a strong enough telescope and place them in the right spot the view of the night sky could be scientifically spectacular. * How Telescopes Changed Our Lives * Telescopes have been an instrumental tool for how astronomers view the stars, ever since Galileo used his in 1609 to look towards the sky and study the moon and the Milky Way galaxy as whole, the world was forever changed. It was with these devices that we learned that the earth is not the center of the solar system or the universe. With telescopes we learned that the moon has craters and mountains, and that Jupiter has storms and that other planets also have their own distinct weather patterns. With newer and more powerful telescopes we learned that there are other galaxy’s, planets and objects roaming the universe, humans were even able to finally understand what the speed of light really comes down to as a value and unit. We have learned so much about the universe through these devices, we know no there are billions of stars and planets and billions of galaxies in the universe. Our understanding of the Sun and our own solar system has grown largely due to telescopes and as time goes on and they improve we are no doubt going to be able to learn much more. * Telescopes Designs * A telescope although used for pleasure on many occasions is actually a very valuable scientific instrument; there are multiple types of telescopes that come in a multitude of sizes and configurations. There are many different types of telescopes that serve different purposes this includes the basic Refractor, radio, x-ray and infrared telescopes to name a few. Of all the telescopes the refractor is the one most people are familiar with, this is the type that was used by Galileo. With a refracting telescope you have a small lens at the front which is what an individual will look through and it will have a large lens towards the back which you would see out of. When you look through both these lenses at the same time it causes whatever you are looking at to be magnified, essentially it will look closer than it actually is, objects can be brought into focus by maneuvering the front portion forwards or backwards by small margins. A refractor telescope comes in two basic designs, standard and Apochromatic, the difference being the way light is focus through the eyepiece. While the standard focuses the light at different wavelengths at different points. The Apochromatic will focus the all the light at one point. The good thing about refractors is that they are portable and a good field of view, while unfortunately they can be expensive and not as powerful as some of the other types of telescopes. * The x-ray telescope is designed to look at x-rays that are emitted from outer space; these are not visible to the naked eye or from earth in general. While there are multiple types of x-ray telescopes the more common ones utilize coded apertures and grazing incidence mirrors. These mirrors are usually created using metal foil or ceramic. X-ray telescopes are excellent for detecting x-ray emissions in space, the unfortunately cannot be ground based and therefore must be launched into space. Radio telescopes are another popular type of telescopes; these are used to study the galaxy for radio emissions. Radio telescopes are different from refracting telescopes because they are not used to visibly look through; instead they are used to listen to the galaxy and the universe. They are usually shaped like a big dish that is fixed on the ground usually in a static location. There is a large area of radio transmission in space coming in at different wavelengths; therefore radio telescopes will utilize different sizes and configurations. This creates a small problem for them as once designed the telescope will usually only be able to locate emissions at a specific wavelength. They are very useful in trying to determine if there is life in the galaxy that is broadcasting any type of transmission in our direction. * Infrared telescopes are another very different type of telescopes from a refractor yet very similar. Like refractors they are designed to detect celestial bodies, although they do so using infrared light. These telescopes utilize an infrared camera in order to view the infrared radiation, utilizing a solid-state infrared detector and the cameras which are required to be chilled hundreds of degrees below zero in order to function. These telescopes can be used in various ways, on the ground, in the air and in orbit so they are very flexible, one of the major downsides of infrared telescopes comes from the ground based ones. As earth’s atmosphere absorbs most infrared radiation so in order for them to function they have to be placed in a dry climate area on a high mountain for maximum effectiveness. * Best Places to Build Telescopes * When it comes to placing a telescope there are many options depending on the type of telescope to be used. Astronomers can place them at almost any place on the planet, although some locations stand out more than most. It is best if they are placed in areas with low light pollution and preferably higher in the atmosphere. This avoids dust and other particles that can disrupt viewing through them. Astronomers placed one of the biggest telescopes on earth the Kech’s twin telescope on the Hawaiian Islands a place which has low light pollution and light cloud cover. * Telescopes on Earth and in Space * To astronomers it’s all about placement of a telescope for maximum viewing effectiveness, there are various reasons why a telescope would be placed on earth or in space. When it comes to earth based telescopes they hold an advantage in the area easy repair access and updating, while the downside is that these telescopes need to get past everything in earth’s atmosphere in order to function to their maximum. Space based telescopes don’t share that issue; there is no pollution from earth atmosphere or light in order for them to get clear pictures. Although getting space based telescopes to their destination is a major process as well as fixing or updating them. * Frequencies of Light * Light as we know it is a form of energy that is scientifically called electromagnetic radiation. Unfortunately for us humans the light we see is limited to a few wavelengths, while there are plenty more on the electromagnetic spectrum that we just cannot see without special instruments. These instruments such as an infrared telescope allow us to see some of those other wavelengths; this can go a long way to filling in the blanks about what our universe is made up of. Understanding the different wavelengths allows scientist and astronomers to better understand how some objects live and how they die. * The Various Wavelengths of Light, Radio to Gamma * As discussed earlier, telescopes and operate in different ways, utilizing different telescopes to view different light wavelengths that are not normally visible to humans. Radio waves have a tendency not to be able to penetrate the Earth’s atmosphere and reach the ground for this reason astronomers use specialized radio telescopes. The main ones used are a very complex set of 27 different telescopes which are about 25 meters in diameter, these telescopes are connected to a computer that processes the information they gather for scientific study. Gamma rays are quite different from radio waves, so in order for astronomers to study gamma rays they must utilize special gamma ray telescopes that use solid-state detectors which will collect the gamma ray information and convert it to either an electrical or optical signal which can then be studied by astronomers. * Conclusion * Humans have always had a natural fascination with the sky, although for a long time they had no real way to study and learn from it. When the telescope was first used to peer at the night sky our world and our views of our place in the universe changed completely. Telescopes can be used by almost any individual in most age ranges, they can be cheap and a great source of entertainment and knowledge. Using these various types of telescopes will allow us to expand our knowledge not only of our planet and solar system but the universe as a whole. At time goes on we will one day use these tools to possible discover life out in the galaxy and find out that we might not actually be alone in this universe. * * * . * * NASA. (2003, September 12). Telescope history'. Retrieved from http://www.nasa.gov/audience/forstudents/9-12/features/telescope_feature_912.html Telescope History. (2008). Retrieved from http://www.universetoday.com/18210/telescope-history/ Types of Telescopes. (2011). Retrieved from http://www.astronomynotes.com/telescop/s2.htm *