Have you ever wished you could hop into a time machine, zip back billions of years and answer one of the age old questions that have plagued mankind from the first time someone peered up into the night sky? To know what exactly happened in the universe that created the chain of events that eventually lead to us crawling into existence? To know what actually happened at the beginning of time, in essence what happened at the Big Bang? Well you are in luck as a time machine with these capabilities has arrived, and no I am not revealing to everyone the existence of a functioning; time traveling DeLorean but rather the unveiling of the ALMA or the Atacama Large Millimeter Array. A massive telescope that will peer so far back to the beginning of the universe, hopefully revealing what the Universe was like those exciting moments after the Big Bang.
Now time travel does not come cheap. Alma comes with the expensive price tag of £1billion but it will be well worth the money. It is the product of three ideas fused into one. Europe, America and Japan had plans for their own arrays; the Millimeter Array (MMA) of the United States, the Large Southern Array (LSA) of Europe and the Large Millimeter Array (LMA) of Japan. They had all planned to build their respective arrays in Chile and this seemed a little over the top to many involved in each of the projects. It was a signing of a resolution between Europe and the USA in 1997 that started the ball rolling on the ALMA in which they agreed to pursue a common project, essentially build one instead of two together. Years of discussions and proposals, resolutions and agreements followed resulting in the ALMA Agreement being signed in February 2003 between Europe and USA. Not long after, in September 2004 Japan agreed to build the ACA or the Atacama Compact array to form the Enhanced ALMA. Together they have built the amazing ALMA which has been well worth the effort.
The location chosen was very important. Chile alone is no stranger to high powered telescopes with many scattered across the country, including ESO’s (European Southern Observatory) VLT (Very Large Telescope) and E-ELT (European Extremely Large Telescope). The appeal as well is in that the Southern sky offers some very unique viewpoints such as the very centre of our Milky Way Galaxy! For the ALMA they chose the high, flat plateau in the Chilean desert of Atacama, called the Altiplana de Chajnantar. This site was optimal for the ALMA with an altitude of 5,000 meters; it is the highest telescope on the planet as well as the most powerful. It is unique also in its harsh surroundings. It is extremely dry in this area of Chile with less than 100mm of rainfall which is perfect for a radio wave detecting telescope.
The ALMA itself is a massive scale telescope with many, many parts. It consists of 66 antennae that are up to 39 foot wide and weighing up to a whopping 100 tons! Spread out over 70,000 square feet on the plateau. The power of this telescope is roughly the same as a massive telescope that would be 14 kms (8.6miles) in diameter, roughly the same distance from Belfast to Lisburn! These dishes will use the technique of interferometry to collect faint radio waves from space and collate all their information together to create an image. This is a very precise process and requires that all the information coming from each of the antennae to meet at the exact same time and point, within one millionth of a millionth of a second to combine and create an image. To do this all the antennae can be simultaneously aimed in one direction of the sky, the antennae capture the signals coming from that area and it gets converted to digital format which is then transmitted to a supercomputer that combines all the signals to create usable date for scientists to use. It is quite similar to how human hearing operates. For people to hear we direct our ears towards a sound, it then reaches the eardrum where the sound is collected and converted into an electrical impulse, which the auditory nerve transmits to the brain, which then analyses the sound and tries to distinguish who or what the sound is. So this remarkable telescope has taken design ideas from the humble human hearing system! What is also special about the ALMA is that these antennae are adjustable! Depending on what scientists are trying to see they can move the antennae using impressive vehicles that weigh 130 tons and have 28 wheels!
The main benefits of using radio waves for the world’s most powerful telescope rather than one that collects optical light is that radio waves can look through dense cosmic dust clouds of space and really see what’s lurking deep in space. It will also help us better understand how planets and stars are formed which is usually hidden behind magnificent clouds and nebulae! One of the first images taken was in the summer of 2011 when there were a sufficient number of antennae to start testing how powerful it could be and they were not disappointed! They targeted a pair of colliding galaxies known, aptly called the Antennae Galaxies can came up with one of the best submillimeter-wavelength image ever made of the messy galaxies! We could see so much more than what normal visible light could, essentially clouds of cool gas where new stars where forming. Definite hope for what the future holds for this ground-breaking telescope.
Nearly 20 years of hard work between Europe, the USA, and Japan and of course Chile has resulted in an impressive giant of human astronomical technology. With its inauguration on 13 March it has already began delivering images that are already breaking preconceptions. On the 5 April they released an image of star formation that is the closest they have ever recorded to the supermassive black hole that lurks at the centre of our Milky Way Galaxy. It has always been believed that the region that is many light years out from the black hole at the centre of our galaxy is too perilous for any star formation to successfully occur with the devastating black holes gravity ripping apart any attempt at infant stars forming. But low and behold, ALMA has discovered large molecular clouds that have become so massive and dense that their own, internal gravity has begun, which would lead to the formation of a star. These are early observations and of course more studying of this area will be required but already a giant leap towards astronomical possibilities has been unveiled by this astonishing telescope.
The ALMA is a telescope that could truly reveal our origins and confirm the beliefs that we truly are made of stardust. With images that will be 10 times sharper than the first space based optical telescope, the Hubble, it will hopefully astound us all. With its already early discoveries it looks extremely promising that this is an astronomical giant we need to keep our eyes on and who knows, maybe we could find out if we are not the only miracle that happened in the Universe and through these intricate radio signals we might have the same success as some of the sci-fi movies such as the enthralling Contact!
(Article by Kerry Scullion, Education Support Officer)