As human beings, we are constantly striving to explore space and widen our knowledge of the universe. This natural inquisitiveness has led to vast developments to life as we know it, dramatically so in terms of technology and the methods of implementing it into science. The ability to look into space is arguably one of the most prolific strands of such developments and over the years has subsequently led to extensive advancements in our understanding of space.

Galileo

Dating back to the early 17^th Century, the telescope was one of the central instruments of what is referred to as the scientific revolution.  Its significance cannot be undermined by any means, having led us to life changing discoveries as a result of its use. The initial birth of the telescope is linked to the Netherlands in October 1608, whereby Jacob Metius and Han Lippershey constructed a device that magnified objects up to four times their original size. Its design consisted of a convex and concave glass lens in a tube. Following this, the next major event in terms of the telescopes’ implementation was by Galileo Galilei, who is often wrongly recognised as its inventor. Galileo managed to substantially better the previous design and made the magnifying strength far more powerful. Eventually Galileo refined his design, allowing it to magnify objects up to 20x. This allowed him to view things up close that no man had ever been able to before. Galileo himself chose to point his telescope in the direction of the sky and as a result discovered vast amounts of new things about the previously not fully understood space above. In many ways this can be regarded as a pinnacle time in the history of our viewing of space as human beings.

The first major discovery by Galileo was the fact that the Moon, in contrast to previous theories, was not a perfect sphere. Indeed, his observations showed that its surface was full of irregularities such as mountains and large craters. Over time he built up a more concrete argument from viewing the planet at different times of the month and sketched diagrams of what he saw, consequently rendering the theory of time and causing mass uproar. Following this, Galileo made many further advances in terms of understanding what he could see in space. Some of these included; the discovery of the Galilean Moons of Jupiter, the phases of Venus, appendages on each side of Saturn, dark spots on the surface of the Sun and the thousands of stars above.

The reflecting telescope

Following the inventor of the refracting telescope, Isaac Newton developed the reflecting telescope. It does not go without saying, however, that many other attempts were made to perfect such a design. None in any case reached the level that Newton did with his design and due to his engineering advantage the “Newtonian Reflector Telescope” is still used to this present day.

Since the initial invention of the telescopes there have been a plethora of different designs, adjustments and advances. The reflector and refracting designs both fall under the category of optical telescopes. These work at either visible, UV or infrared wavelengths. Optical telescopes work with a certain level of simplicity in comparison to many other modern devices. The object in view reflects light, which is then channeled through the end of the telescope into the lens or mirror. This light is then focused onto a focal plane where the object in view is formed and then viewed through the eyepiece, which magnifies the image.

Another more modern way of looking into space is through the method of radio astronomy. This is essentially the viewing of the invisible universe that our eyes cannot detect. It allows the study of astronomical phenomena that are often invisible in other areas of the electromagnetic spectrum.  As a result scientists are able to study cosmic microwave background radiation and study some of the earliest existing galaxies. Moreover, since radio waves can pass through many non-metallic objects, scientists are able to use them to see dust shrouded environments where stars and planets are born as well as the center of our galaxy.

Seeking to look further and further into the deepest realms of space, scientists identified several key issues that stood in the way of achieving

The Hubble

such goals. One of these key barriers was the earth’s own atmosphere that distorts and blocks light that reaches our own planet. NASA’s Hubble telescope was a means of overcoming these restrictions and one of the most successful and long-lasting science missions taking hundreds of thousands of images of the furthest reaches of space. The Hubble telescope has orbited earth since its initial launch in 1990 and completes a full orbit of the Earth in less than 100 minutes. The telescope itself is referred to as a Cassegrain reflector whereby light hits the primary mirror and is reflected into a secondary mirror which then captures the light and directs it to several scientific instruments on board the satellite. Scientists are able to examine various wavelengths of radiation such as UV, gamma and X-rays before they reach our planet.

The discoveries made by the Hubble telescope can in many ways be regarded as some of the most important of its time in astrological terms. Key developments include giving a more accurate estimation of the age of the universe and taking photos of distant galaxies to show what our own would have looked like billions of years ago. Prior to the Hubble, no telescope had seen these galaxies and scientists used methods of focusing the telescope into one particular area for up to 10 days to allow it to fully soak up all the light.  In the time following this, the Hubble team examined parts of space in high definition, prolonging exposure and multiple wavelengths by carrying out similar practices. Moreover, being able to pinpoint the age of our universe to roughly 13.7 billion years, scientists have been able to create a time scale for the development of stars and further refine our models of the universe.

The hundreds of extra-solar planets found by the Hubble are further examples of the capability of this powerful piece of technology. Previously, ground telescopes found such planets by searching for wobbles in the motion of a star as a planet tugs at it, or though the dimming of light as a planet passes in front of its parent star as it orbits. However, the Hubble is able to provide a more in-depth look when viewing such objects and has since been able to take the first pictures of an extra solar planet in visible light 150 trillion miles away.  Not only this, but in 2009 the Hubble captured photographs of a rare comet crash into Jupiter showing a sharp visible light image of the impact using its Wide Field Camera 3. By combining different images taken from other sources astronomers were also able to enhance their viewing of the event. Indeed, the addition of  mid-infrared images from a ground based telescope gave insight into the changes in the vertical structure of Jupiter’s atmosphere as a result of the impact. This showed a plume of debris due to the turbulence in Jupiter’s atmosphere.

The Hubble, however, is not the only space telescope to be functioning on the basis of visible light. NASA launched the Kepler Spacecraft Mission in 2009 with the aim to find earth-sized planets that have potential to be inhabited by humans. It works by surveying a large sample of stars using the most powerful camera in space at 2200×1024 pixels. NASA stated that some of the main aims of using the Kepler Spacecraft to look into space include the following:

• Determine the abundance of habitable terrestrial and larger planets in the zone of a wide variety of stars;
• Determine the distribution of sizes and shapes of the orbits of these planets;
• Estimate how many planets there are in multiple-star systems;
• Determine the variety of orbit sizes as well as the sizes, masses and densities of short-period giant planets;
• Identify additional members of each discovered planetary system using other techniques;
• Determine the properties of those stars that harbour planetary systems

Ultimately these aims highlight the importance of being able to look into space as human beings, when being able to physically access the places is of great difficulty and expense or indeed impossible. Looking into such space allows us to develop our understanding of our universe and ultimately progress as a human race.

Gamma ray telescopes are another relatively new way in which astronomers are viewing space and detecting the highest energy photons, which pass through most materials. These kinds of telescopes can only be used in space missions due to the fact that the atmosphere absorbs such radiation and thus cannot be detected on earth. Because gamma rays cannot be captured or reflected in the way that optical light can, they have to utilise a different process called Compton scattering, in which gamma rays come into contact with an electron and it subsequently loses energy. Gamma ray telescopes allow us to take unique views of space; they allow us to see things like solar flares, neutron stars, black holes, supernovae and active galaxies. Such views of space is important to scientists and astronomers alike due to the fact that they are able to test theories and perform experiments that are not possible to be carried out on Earth and as a result discover new physics.

The Spitzer telescope is another means by which NASA are observing the universe in a different way. The telescope, which is used as part of a four family observatory group, is able to detect infrared or heat radiation. Like its gamma counterpart, it is able to view far further than optical light telescopes – observing stellar nurseries, new planetary systems and the centre of galaxies. Being the largest infrared telescope ever launched into space, it goes without saying that its design is very complex and requires specific conditions to function properly. The Cryogenic Telescope Assembly, which is home to three scientific instruments, must maintain a temperature that is several degrees above absolute zero through using a tank of liquid helium. In contrast, the rest of the spacecraft must be stable to operate at room temperature. Moreover, as well as being able to view heat-emitting objects in space, the Spitzer is also able to access such things as failed stars, molecular clouds and organic molecules – which are far cooler.

Aside from multi-million pound government funded projects seeking to visually explore space, another form of astronomy that must also be given recognition is the everyday amateur astronomy enthusiast. Although amateur astronomers do not set out with goals of major scientific contribution, more often than not it is these people who provide important information and discoveries to bigger bodies and organisations. Using readily available optical telescopes available from high-street shops, amateur astronomers work on budgets and are restricted by their access to high-end equipment. Nonetheless, vast amounts of dedicated amateur astronomers still manage to make vital contributions. In one particular case, a teacher of the Midlands achieved world reputation as an astronomer, discovering six comets, several novae and many thousands of observations of variable stars, despite never owning a telescope and carrying out all his work using a pair of binoculars.

In relation to this, another vital part of our perception of space are the ways in which we see it with our naked eye. With the endless amounts of technologically advanced equipment and large organisations dedicated to astrological exploration, our unaided perception of space from earth is often overwhelmed. Simply looking into the sky on a clear night reveals an array of stars and constellations to the naked eye. In many ways this is how we all share a connection in terms of the way we view space. There are a variety of things we can see through the naked eye when looking into space; one of the most prized spectacles is witnessing a shooting star and with advanced technology of wider corporations we are often able to forecast such events. Other things viewable by the naked eye include the Milky Way and the Andromeda Galaxy; however this is often difficult to see due to the presence of light from urban areas. Lunar and Solar Eclipses, which scientists are able to predict, can also be seen with the bare eye. Throughout different part of the year we are able to witness various constellations in the night sky such as Orion in winter evenings and the Great Square of Pegasus during the autumn.

Despite the endless funding and research contributing to our knowledge of space, there are still many questions that we as humans have yet to answer or find a definitive conclusion for. One of these key questions is discovering what dark matter and dark energy is. Astronomers have recognised that objects in the universe are held together by this matter that gives off no light and is likely to consist of undiscovered elements. Additionally, discoveries that show the universe is speeding up in expansion suggest the presence of dark energy that repels, instead of attracting, energy. The questions do not end there, however; the explanation behind ultra-high energy particles is something which has stood in the way of scientists since their discovery. The source of these unexpectedly high beams of energetic particles is only to be guessed by scientists, currently ranging from objects such as active galactic cores to hyper-novae.

Space Rubble

Ultimately, the key reason as to why we have such instruments and devices to aid our vision into space is to allow us to see what exists in the sky above and beyond. Besides looking into space, scientists seek to observe obvious things such as other planets and stars, with more powerful and refined equipment organizations such as NASA being able to see and visually explore further than ever before. Such things as clouds of interstellar dust form clouds and make up the solar wind, which astronomers look for when looking into space. Moreover, there are often areas of isolated particles and hydrogen atoms, which often form clouds over a billion kilometers wide called ‘nebulae’.  As well as this, astronomers look for the likes of planetoids and asteroids often referred to as “space rubble”.

Potentially, looking into space may hold the key to our future as human beings and the existence of life outside our own planet. With the limits of not being able to physically travel to such areas of space it is vital that we harvest as much as we can by looking into such areas using the technology we currently have and unearthing more and more about the origins, compositions and construction of our universe. With impending pressures such as global warming and depletion of natural resources it is now more important than ever to look into and explore space.