Four centuries ago, Galileo Galilei first used the telescope to study the heavens, which led to an earth-shaking discovery - contrary to long-held Aristotelian claim, the Earth is not the center of the universe. It just revolves around the Sun.

The revelation led to his persecution by the Catholic Church, whose current pope, Benedict XVI, now praises Galileo for setting the astronomical facts straight. Thanks to the telescope and the Italian who had the idea of seriously pointing it to the night sky, we now distinguish astronomy from astrology and cosmic myths.

To celebrate the 400th anniversary of the first time Galileo used the telescope, the United Nations declared 2009 as the Year of Astronomy. Perhaps it's time for more individuals to take a better look at the sky too. And for that you need a telescope.

Some observatories are kind enough to let laypeople have a short peek into their telescopes. And we've all seen photographs of colorful, awe-inspiring images of galaxies made possible by the Hubble telescope. But nothing beats the convenience of having your own telescope right at home.

You don't need the Hubble or the Kepler telescope to make an amazing discovery. Amateurs in a less-known neck of the woods (in Cebu, Philippines, to be exact) have discovered that Jupiter doesn't only have one red spot; it has two other smaller ones in fact. And they saw those spots using telescopes no bigger than their own bodies.

Let us take a look at the two basic types of telescopes amateurs use: the reflector telescope and the refractor telescope.

The reflector telescope is ideal for beginners. This is because it doesn't give distorted images. It uses mirrors that are opposite to the lenses that collect, reflect, and focus the light for better viewing. It is also known as the 'Newtonian reflector,' in memory of the great Isaac Newton.

The refractor telescope, on the other hand, uses lenses to refract the light. It is reliable and easy to use for terrestrial viewing at daytime.

Speaking of the price, reflectors are cheaper than refractors. If you're a newbie, you can try the cheaper kind first. But generally, it's not an expensive hobby. Commercial telescopes cost just around $500. A pair of powerful binoculars makes a good alternative if you only have $200 in your pocket.

The latest design in amateur astronomy telescopes offers the best of both types. The catadiotrophic telescope is scientifically and commercially designed with the characteristics of both the reflector and refractor. It uses both lenses and mirrors to help you magnify distant and small space objects with ease.

And which telescope brands will you choose? Most amateur astronomers suggest these manufacturers: Meade, Bushnell, Orion, and Celestron.



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What does it take to become an astronomer? Well, curiosity is a requisite. It's what fuels you to look at the night sky, wondering about outer space, its objects and energies, how the universe began and the sheer magnificence of its lights and vastness.

If you want to make a career out of 'stargazing,' it may not be enough to just look skyward at night or name the constellations. Being an astronomer entails a lot of work, observations and academic studies, and one has to network with other astronomers and secure funds for equipment purchase and upkeep and other expenses.

But astronomy, which has gained steadily increasing popularity among 'stargazers' the world over, is not just for people with PhD's in planetary science or astrophysics. There are a watchful army of observers armed with simple telescopes, keeping their eyes on certain sections of the night sky.

Amateur astronomers have in fact made some contributions to astronomical studies. Gazers in Cebu, Philippines, for instance, have discovered the two more red spots on planet Jupiter.

To help you get started in astronomy, here are some things you need to have:

Telescope(s). You may try good reflectors, which are far cheaper to start with and provide better viewing. If you want, you can try out the popular telescopes from Meade, Orion, Bushnell and Celestron. These are the leading manufacturers of quality telescopes for astronomy amateurs. If you want to make your own telescope, simply find some do-it-yourself instructions on the web and purchase the parts.

Map. You can download stargazing maps from some websites. You can't just point your telescope at any direction without any clue of what you're looking at. The sky is too wide and you need a good telescope to locate certain heavenly objects accurately.

Astronomy book. Studying astronomy is a lot of headwork. Your observations must be guided by theories and information on astronomy. Although there is a multitude of astronomy books out there in the library, you may also surf the internet, or try "Turn Left at Orion," which also teaches you how to use your telescope.

Notebook. Jot down your observations, impressions and discoveries, be it on a paper notebook, a handheld gizmo or a computer.

The stars look good from way up there at night. They beckon. And astronomy needs more eyes checking the wide sky for - take your pick - stars, planets, systems, galaxies, comets, meteors, asteroids, near-earth objects, and a lot more. But first, you have to be curious enough.



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Stars are out of reach. But, there is a way to soar at the top and let countless stars be captured by one sense organ. Know what it is? Definitely it is not your skin. That takes a hundred lifetimes. Do not scratch your head. Look above and peer into the stars and that's it. You can capture the stars with the use of your eyes! But have you done a lot of stargazing ever since?

Acknowledging the truth that no one can conquer the swiftness of time, not even H.G. Wells, and the light years distance of stars, it will soon launch and land on your mind that it is possible to watch the stars at a seemingly short distance. How to do it? Thanks to the mothers of scientists, scientists have given birth to gadgets that can make us peer not only into the twinkling stars, but to the balls of fires light years away from us. To be specific, let me welcome you to Bushnell telescope guide, your guide towards the stars up in the sky.

Bushnell telescopes are the best in the land today. No wonder because its years of expertise have given its manufacturers enough mind food to find out what telescopes will satisfy its users. With utmost commitment, Bushnell caters to the optical needs of professionals and professional wannabes. Hence, all sorts of telescopes Bushnell offers come in three variants namely reflector, refractor, and compact.

For beginners, there are telescopes at least as many as the fingers in one hand of any animated character that can be purchased now. Help me count with your fingers as I enumerate the binoculars. For one, there is Bushnell NorthStar Series Telescope which uses push-button controls to send your eyes near to the 20,000 objects at the firmament. Plus, there is real voice output that can make you interact with the shimmering night sky.

Number two, there is Bushnell Telescope Discoverer Series which can take you beyond the sky. Possible? Definitely yes right when you peer into this telescope. Like the previous, it has real voice output with a real human voice to guide your eyes on their journey towards the celestial treasures above. With RVO, you will be personally introduced to each constellation. That's an interactive way of making friends with the stars.

Right now, hold your longest finger because it's Bushnell Telescope Voyager Sky Tour Series turn to be known. This telescope with a long name gives amateur's eyes a pro-grade audio voyage into the sky. Aside from the talking handset that introduces you to the constellations, it is equipped with Illuminated Smart Mount that pin points the way teacher does to the stars being referred to.

At your forefinger spot is the Bushnell Telescope Harbor Master Series that comes with tripod legs incapable of walking but just standing up. Beneath this classic telescope is a completely modernized high powered 35x 76mm telescope able to give you brilliant images and sharp as samurai blades resolution.

The foregoing are just four of the many telescopes Bushnell can offer. If you want more, visit their official site. Be sure you will read the reviews and features to come up with the best eye tour guide you can possibly have.



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In March, the launch abort system - also known as the LAS pathfinder - for NASA's Orion crew exploration vehicle began a week-long journey across US to be delivered to White Sands Missile Range in New Mexico, where it will help NASA prepare for the first abort system test, known as Pad Abort 1. The LAS pathfinder represents the size, outer shape and specific mass characteristics of Orion's abort system. This has created waves about Orion.

Orion, as you know, will become Nasa's primary vehicle for human space exploration after the shuttle retires in 2010. It will carry astronauts to the International Space Station and eventually to the moon and beyond. The vehicle is scheduled to begin carrying humans to the International Space Station in 2015. For its return to Earth, Orion will be equipped with a system of parachutes and shock absorbers.

Orion is making a big splash. A mock-up of the spacecraft that will carry the next generation of astronauts to the moon and beyond is traveling down the East Coast and undergoing tests to help NASA understand its performance in water.

'One feature is its high mobility,' writes Nasa on its website. 'Each set of wheels can pivot individually in any direction, giving the vehicle the ability to drive sideways, forward, backward and any direction in between' - a bit like a supermarket trolley.

The LAS pathfinder - for NASA's Orion crew exploration vehicle began a week-long journey across US to be delivered to White Sands Missile Range in New Mexico, where it will help NASA prepare for the first abort system test, known as Pad Abort 1. The LAS pathfinder represents the size, outer shape and specific mass characteristics of Orion's abort system.

NASA really led in the space technology section and here once again it make the technology wall more strong by contributing LAS path finder. Innovation is the hobby of NASA and valuable move proof its researchers hard working. Its preparation for the first abort system test, known as Pad Abort 1 can be declared here as IT bomb on the tree of technology.



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Bushnell telescopes are considered to be the best telescopes in the market today. Bushnell, with its expertise and years of experience in optics has come out with some great products which are not only suitable for amateur astronomers, but they are also well suited for professionals who prefer heavy duty telescopes to view stars over longer ranges.

One of the best product lines to be manufactured by Bushnell are the Voyager telescopes. Available in three different variants, these are available in reflector, refractor and compact variants. Each of these variants is designed to suit specific purposes and therefore, it is worth noting that you purchase one of these high end- high quality and high technology variants only after jotting down all your requirements and specifications.

The reflector Bushnell telescopes are based on light gathering technique and offer great magnification as compared to other brands in the optical industry. Boasting of eyepieces with dimensions of 5mm and 27mm, these are carved out of light weight and well balanced alloys and are also supplied with body straps, making them predominantly portable telescopes. The refractive models, on the other hand are more expensive and are heavier as well, but deliver the best quality in its class and therefore, are great for those who star gaze from static locations and don't need to carry their telescopes over a longer distant in order to get a clear view. Refractive models offer better magnification (up to 5 times better than other models) and are also considered to be better in terms of camera adaptability and auto focus features. Being camera adaptable is one of the most advanced features offered in Bushnell telescopes and therefore, telescopes manufactured by Bushnell are considered to be way ahead of the competition. Besides, they are aptly suited for a wide range of stargazers, from the casual and educationists to the professional astronomers, Bushnells are a hit with stargazers of every level.

There are so many brands in the market for Telescopes. It is always best to search for exclusive telescope website to read reviews, find best selling models on Meade, Tasco, Zhumell and Bushnell Telescopes. Celestron Telescopes also has lot of choices to choose from beginners to professional.

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Do you like the idea of exploring the universe from your own backyard? The truth is that you don't need a telescope to get started! Lots of people find that simply buying some astronomy binoculars will help you get the view of the heavens that you are after. When you are looking for telescope binoculars and if you are in a place where you want to really figure out what your options are, you'll find that there are a number of different options available to you. Check out some of the specifications that you can use to ensure that your astronomy binoculars are precisely what you are interested in.

Magnification
When you are looking at the magnifying power, you will see it given as two numbers, maybe something like 6 x 30 or 7 x 35. The first number is how many times the object that you are looking at is going to be magnified, while the second number refers to the diameter of the objective lens in millimeters. What sort of magnification do you need when you are thinking about doing some star gazing? While a higher magnification will let you cut through light pollution more effectively, remember that ti will also narrow your field of vision, making it much harder to figure out "where you are." Higher magnification will also heighten the movement of the stars. If you are working with hand-held astronomy binoculars, a magnification of 10 is usually the highest level recommended.

Objective Lens Diameter
The second number refers to how wide the lens is. The wider the lens, the more powerful the telescope binoculars' ability to gather light. It gives weight and bulk to the objects that you are seeing, and you'll find that this adds a very real, very 3D effect to objects you are seeing. This measurement is also known as the aperture, and the larger the aperture, the brighter the image is, and the better the resolution is.

Roof vs Porro Prism
The prism is essentially a triangular piece of light-reflecting glass that has polished edges. It serves to fold the path of the light and it flips the image so you don't see it upside down. The traditional prism that you will have available to you is the porro prism, which is shaped like a Z. It's great for astronomy, and it will reflect the path of the light three times. A roof prism model, on the other hand, is more compact, the path of the light is longer as it will fold four times. Like a porro prism is good for astronomy, a roof prism is preferable for things on the ground.

BaK-4 vs BK-7 Phase Coating
You should also have a look at what is used to coat your astronomy binoculars' prism. BK-7 refers to a coating made of boro-silicate glass, while BAK-4 uses barium crown glass. The latter is usually preferred for the purposes of star gazing is it has a higher density and because it reduces the amount of light scattering. Using BAK-4 phase coating gives you a sharper picture.

Take some time to figure out what handheld astronomy binoculars are best for you!

For more information on handheld astronomy binoculars, please visit Telescope Binoculars.

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In this short article I am going to briefly discuss the distribution of matter in the Universe at different scales as well as to give some basics of modern cosmology.

Let me start with the first smallest scale interesting from the cosmological point of view - the size of the Solar system. This size is about 50 AU (Astronomical Units) ≈ 7.5 billion km (kilometers) if we decide to set the boundary of the Solar system at the Pluto's orbit. The gravitational field of the Sun dominates over the field of nearest stars up to the scale ≈ 2×10^13 km = 20000 billion km. This scale can be also considered as the size of the Solar system in some sense, although the average density of matter (gas, dust, etc.) is extremely low beyond 100 billion km distance from the Sun.

The main source of visible light in the Universe is nuclear fusion within stars (mainly, hydrogen into helium). Our Sun is a typical yellow dwarf star with approximate mass 10^30 kg - 100 times more massive than all planets of the Solar system combined. One can say that we live in the gravitational well of a rather small star, since there exist stars within our Galaxy 100 times heavier than the Sun. If we consider only nearest stars, the scale of the box containing them is of the order 1 light year, the length of the path passed by a ray of light during one year. For example, the closest star, Proxima Centauri, is 3.261 light years ≈ 1 parsec (Pc) away from us. The name of the unit "Parsec" comes from the fact that Proxima Centauri has a parallax of approximately 1 arcsecond. Taking into account that the velocity of light is about 300000 km/second, one can check that 1 light year ≈ 10^13 km, while 1 parsec is ≈ 3×10^13 km.

The size of the box containing nearby stars is therefore about 1 parsec. If we increase the size of this box 1000-fold, we find that clusters of stars, interstellar gas, dark matter are combined into gravitationally bound conglomerates of matter called galaxies. The Solar system is located way off center in our Galaxy within what is called the Orion spiral arm. The name is due to the fact that stars from the Orion constellation such as the red giant Betelgeuse - the ninth brightest star on the sky - belong to the same arm.

The typical number of stars within a galaxy is extremely large. For example, our native Galaxy (the Milky Way) contains 100 billion (thous. million) stars. It has a form of disk with the radius 12500 parsecs and the thickness of only about 300 parsecs. This extremely thin disk is rotating differentially with the full period of about 200 million years - so, dinosaurs were wiped out from the face of the Earth during the previous galactic year. Large old galaxies (including the Milky Way) have usually a form of spiral. The reason is that rotating disk of gravitationally interacting dust particles is unstable, and this gravitational instability breaks the disk into a spiral-like structure. The characteristic length scale of the box containing only our Galaxy but not other galaxies is 10000 light years.

Let us now again increase the size of the box, 10-fold this time. We will find that the Milky Way resides within a small concentrated group of galaxies (LGG). All the adjacent galaxies in this box are much smaller than the Milky Way being located within its gravitational well (in other words, they are satellites of our Galaxy in the same sense as the Moon is the satellite of the Earth). The closest galaxy to the Milky Way is Large Magellanic Cloud (50 kiloparsecs, that is, 50000 parsecs ≈ 1.5×10^18 km away). The nearest galaxy of the size of our own (actually slightly larger) is 770000 parsecs away and is named the Andromeda galaxy. A typical local group of galaxies occupies a volume of few cubic Megaparsecs, i.e., millions of parsecs. Megaparsec is a cosmologist's favorite unit, 1 MPc ≈ 10^22 m. These groups of galaxies in turn are grouped themselves into galaxy clusters (some of these clusters contain more than 10000 galaxies). Our local group is within the gravitational well of the so called Virgo Cluster.

Let us again increase the size of the box 10-fold. Not surprisingly, it turns out that galaxy clusters are combined into superclusters, but surprising it is that the latter are the largest gravitationally-collapsed objects in Nature - in other words, there is no such thing as supersuperclusters of galaxies in the Universe. The structure of superclusters and their interplay due to the gravitational interaction becomes noticeable at scale about several hundreds of millions of light years or hundreds of megaparsecs. Namely, superclusters are joined by filaments and walls of galaxies creating a foam-like structure of matter and gravitational potential called the Cosmic Web. Voids in this Web are as large as 50 megaparsecs across.

Understanding that the structure of the Cosmic Web is defined by the gravitational instability and the latter needs some time to develop, on can conclude from the fact that superclusters are the largest collapsed objects that the age of the universe was finite and, moreover, its initial state was highly symmetric. Indeed, let us again increase 10 times the scale of the box. What we will find is the map of the Universe (approx. 2 million of nearby galaxies) with characteristic scale about 3000 megaparsecs. This coincides with the size of the observable patch of the Universe - that is, we are unable to probe the physics beyond this scale even with the best astronomical instruments we currently have (like Hubble Space Telescope). Within this patch of the 1 gigaparsec size, the Universe is extremely smooth, homogeneous and isotropic. In a sense, that is why qualitative discussion of the evolution of the Universe is possible at all and cosmology can be considered a legitimate daughter of astronomy. Of course, fluctuations of the matter density are present in this homogeneous Universe (we are living within one such fluctuation), but their relative amplitude is about 10^-4 ∼ 10^-5 at scales of the order 1 gigapersec.

Although cosmologists do not have any data on the distribution of matter and gravitational potential at scales larger than 1 gigaparsec, theory shows that the qualitative picture above does not change up to the scale of 13 billion light years (the cosmological horizon scale) , although the relative amplitude of fluctuations starts to slightly grow while the scale gets larger and larger. Standard inflationary paradigm predicts as well that the relative amplitude of fluctuations of the gravitational potential keeps growing until it becomes of the order of 1 at the so called eternal inflation scale LvEI ∼ 13 billion light years × e^N, where the number N is more than 60 and depends on particular inflationary model. While the Universe is homogeneous and isotropic at scales below, it again ceases to be homogeneous and isotropic at L > L^EI. Moreover, it can be considered fractal in a certain sense - the structure of the gravitational potential at these huge scales turns out to be self-reproducing.

Thinking in terms of propagating light and recalling that the speed of light is the largest possible speed in Nature, one can understand that distance or length scale in general relativity - theory governing physics at astronomical scales - is quite the same thing as time scale. In other words, larger distances correspond to earlier stages in the evolution of our Universe because more time had to pass for light from distant objects to reach us. Observing the Universe, we are watching a movie, its first shot corresponding to extremely distant objects on the sky and the last - to physics at scales of the order of the Solar system's size.

This article was originally published at http://www.nonequilibrium.net as a part of the lecture course on modern cosmology and large scale structure of the Universe.

http://www.nonequilibrium.net is a blog where a community of professional theoretical physicists - cosmologists, high energy theorists, condensed matter theorists - discuss their current work as well as cutting edge physics.

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