محبت مجھے ان جوانوں سے ہے
ستاروں پہ جو ڈالتے ہیں کمند
The youth to whom the stars are not out of bounds,
are the ones I love indeed.
When I was a child, we had a large paint board outside our tyre shop in Layyah, Pakistan. It was a painting of a lonely country house with snowcapped mountains in the backdrop and a sky full of stars. In one corner, a boy sat gazing at the sky. At the top, this Urdu verse by Allama Iqbal, the national poet of Pakistan was written. Whenever I was at the shop, I found myself staring at the picture of the boy longing for the stars. There was a powerful message—to dream big; to go higher and to reach out for the stars.
Decades later, I found myself on the other side of the planet visiting the ALMA observatory —one of the most ambitious astronomy projects in the world. To me, ALMA appeared as a direct manifestation of Allama Iqbal’s verses—being ambitious and exploring the worlds far far away. Allama, and ALMA, even sound similar.
The ALMA project searches for clues to our cosmic origins in the outer space. This essay describes my visit to ALMA in July 2016, how it works, and why this project is so important for humanity.
I happened to cross the Atacama Desert by bicycle on my way from Ushuaia, Argentina to Alaska. Due to its dry weather and clear skies, the Atacama Desert in northern Chile is an ideal location for many astronomical observatories from around the world. Chile also has a thriving scientific community, is very welcoming to astronomical observatories; and has offered its land to many international observatories.
When I was passing through this region, I first made a visit to the Paranal observatory and later applied for a media visit at the ALMA observatory. Every month, there are only about 3 media visits, each approved by the director of ALMA. The approval can take several weeks but I was extremely lucky that my media visit request was approved within a couple of days.
In San Pedro de Atacama, I rented a 4×4 vehicle and drove to ALMA in the early morning. After the gate, the road was unpaved and climbed at a steep gradient to the OSF (Operation Support Facility) at 2900-m where the astronomers operate. There, I went through a medical checkup. A nurse checked my blood pressure and pulse rate; both were okay. I was declared fit to visit the ALMA antenna site at the Chajnantor Plateau at an altitude of 5000-m above sea level. But, my guide wasn’t there. I waited for him outside the clinic. After about 10 minutes, I received a call from him.
“Hey, I am Danilo. Where are you?”
“Outside the clinic.”
“OK, I am coming, don’t go anywhere”
Soon, he was there. He was worried because he had been searching for me for an hour.
“Where is your bicycle? I thought you will be coming here by bicycle!”
“I didn’t know that I could enter ALMA by bicycle, otherwise I would have done so”.
“Let’s first go to the antenna site because the weather up there can get worse any time.”
I parked my car and jumped into his car. We drove up on a 28-km long windy road to the antenna facility. On the way, my guide reported his location at various points on radio for safety reasons.
After about 40 minutes, we arrived at the Area Operation Site (AOS). The Chajnantor Plateau looks like the moonscape. The large, flat and dry area is surrounded by mountains in the far distance. 66 giant dish antennas dot the landscape but appear minuscule in the vast emptiness. A strong cold wind blew and penetrated through thick layers of my clothing into my skin. Danilo drove me through the antennas, where I took a few photos. Then we went up to a higher point which provided a panoramic view of the antennas. I stepped out of the car for a couple of minutes to take some photos but the bitterly cold wind froze my hands. We rushed back to the heated glass-walled building at the site, where I was given hot coffee and biscuits.
What is ALMA?
ALMA is the highest observatory in the world. With the help of an array of 66 high precision antennas spread over many kilometres, ALMA enables scientists to look into the depths of the cosmos and probe stars and galaxies, image exoplanets and possibly even discover the first traces of life. Examples of what ALMA is trying to see include:
What did the solar system look like when it was still forming? It is not possible to go back 4.6 billion years to take a look. But there’s another way – we can look at solar systems which are currently forming. This will give us a good idea about how our own solar system was formed.
How are stars formed? In some regions of space between other stars, the density of gas and dust forms molecular clouds that allow the formation of delicate, complex molecules. When a molecular cloud reaches a critical size, mass or density, it begins to collapse under its own gravitation, forming a solar nebula. The solar nebula becomes denser over the time. It is from the solar nebula that a new low-mass star is born. The young star keeps gathering mass from its molecular cloud, a process which can last for about one million years. Understanding how these phenomena occur can help astronomers understand how our own solar system and earth were created and how life began.
The ALMA project is an international partnership of Europe, North America and East Asia with the Republic of Chile. The groundbreaking work on the observatory began in 2003 and the observatory was inaugurated in 2013.
What does ALMA see?
What we see with our eyes is the ‘visible light’ which consists of different colours–each colour has its own wavelength. We have been studying the visible light using optical telescopes for centuries. But the visible colours of light are only a small part of the entire electromagnetic spectrum. Many other animals and insects have the ability to see beyond what we see. For example, infrared light (‘heat radiation’) cannot be seen by people, but it can be seen by snakes. We cannot see ultraviolet light, but it is visible to bees.
The universe emits light in many different invisible colours or different radio wavelengths; from the extremely long radio waves to the ultra-short gamma rays. ALMA observes the universe in radio waves using non-optical telescopes. The large antennas at ALMA measure the millimetre and sub-millimetre (mm/sub-mm) wavelengths emitted by cool-temperature objects in space. The mm/sub-mm wavelengths allow ALMA to look deep into dusty clouds where stars are being born. This helps the scientists to study the formation of planets occurring within complex dusty molecular clouds. Only longer radio waves can escape from such regions, as the visible light is blocked and scattered by gas and dust.
The first stars and galaxies that emerged from the cosmic “dark ages” after the Big Bang billions of years ago, can still be seen as most of their light has stretched out to mm/sub-mm wavelengths due to the expansion of the universe. This is what ALMA is trying to see.
Why the Atacama Desert?
Ideally, the best location for a telescope would be in space, to ensure that the atmosphere above the antennas contains no moisture. If there is humidity in the atmosphere, the millimetre radio waves from outer space would be absorbed by the water molecules in the air before they reach the antennas. However launching multiple antennas into space will be absurdly costly. On earth, the best location for a radio telescope is a high spot with very thin and dry air.
The Atacama Desert is, therefore, the best location for ALMA. High and arid Chajnantor Plateau at 5,000 meters above sea level puts the ALMA’s antennas above 40% of the earth’s atmosphere. The sky here, is very clear and cloudless all through the year, giving scientists almost 95% observable time.
The area has very little light pollution or radio interference from the few small villages in the region, most of them at least 40 kilometres away. Furthermore, the flat and extensive high-altitude plateau allows the antennas to be distributed across an area of up to 16 kilometres.
Chajnantor also has geographic advantages due to its relative proximity to the equator ALMA can see important objects in the southern sky as well as much of the northern sky.
Here, wild animals share the region with ALMA. Foxes are native to this region and can be seen at the antenna site. Wild donkeys have lived here for the last couple of hundred years. They are non-threatening to the humans. As Danilo, my guide, aptly put in words, “we are the visitors, not they.”
The region is inhabited by various kinds of endemic cactuses. “Different types of cactuses are found at different elevations. So basically, they are nature’s altimeter.” Danilo added.
How does ALMA see?
ALMA’s 66 antennas are its eyes. Since radio waves they are trying to see are much longer than visible light, the telescope diameter must be correspondingly larger to obtain larger angular resolution. ALMA’s giant antennas are either 12-m or 7-m in diameter. The antennas are very precisely made from multiple panels and are very robust. Even in the harsh climate of the Chajnantor Plateau, they maintain a perfect parabolic shape over its entire surface, to the fraction of the thickness of a human hair. Each antenna weighs around 100-tons and comes at the price of about 50 million USD!
Inside an antenna, there is a radio receiver with temperatures maintained at -270°C (close to absolute zero -273°C, the lowest possible temperature). At this temperature, the atomic motion is at the minimum which suppresses noise in the components and allows the receiver to listen to extremely faint signals coming from outer space.
The ALMA antennas can also be moved around. Input from multiple antennas can be combined to create a single image. If the antennas are close together, they act like a single wide-angle lens on a camera providing a large field of view of the sky. When moved far apart, they act like a telephoto lens, proving a view a small part of the sky, but in much greater detail. The ability to reposition its antennas is what makes ALMA such a powerful telescope.
Each antenna weighs over 100 tonnes, moving which requires specially designed vehicles. The monster transporters are made by a German firm and named Otto and Lore. Each of these weighs 130 tonnes and is 20 meters long, 10 meters wide and 6 meters high, and has 28 tires. Despite their size, these vehicles are able to position the antennas to an accuracy of a few millimetres on the antenna foundation pads. Their maximum speed is 20 km/h when empty, and 12 km/hour when carrying an antenna. Although special training is required to drive these trucks, there is no special license required.
The ALMA Correlator
The eyes of ALMA are connected to its brain (a large supercomputer) through tens of kilometres of optical fibres. These fibres transfer the signals from antennas to the main computer, which is called a Correlator to create high-resolution images from the digitised millimetre radio waves.
The ALMA Correlator is one of the fastest supercomputers in the world. It has 134 million processors providing a combined processing power of about three million personal computers. Together, they carry out 17 trillion calculations every second. They combine signals from the antennas using the precise location of each antenna and the precise time when a signal is received, with the possible timing error no larger than a millionth of a millionth of a second.
Central archive and data distribution
From the Area Operation Site (AOS) we drove back to the OSF where the ALMA control room and offices are located. The control room displays an array of monitors. On one monitor, the figure 54/66 indicated that 54 antennas were working at that time.
The operator in the control room showed me the software which they used to monitor and control the antennas. With my background in computer science, I was keen to learn more about how the software worked.
“How are the radio signals converted into images?” I asked.
“Using the Fourier Transform” he replied.
I remembered Fourier Transform from a course on image processing during my master studies. It always gave me a big headache! I refrained from asking more questions about the topic.
The digitised radio signals are converted into images at the AOS site and sent to the Operations Support Facility. From here, the processed observation data are sent to the central archive in Santiago, and then to the ALMA regional centres in North America, Europe and East Asia. There, astronomers receive the observation data and can analyse it. At its maximum capacity, the observation data library at ALMA grows at the rate of 800 GB per day. The following picture summarises the steps.
What has ALMA seen so far?
Scientists from all over the world submit observing proposals to ALMA. The best proposals are chosen, but special consideration is given to researchers from the countries that are financing the project. 10% of observation time is allocated for the host country, Chile, and 90% for the partners in accordance with their financial contribution to ALMA.
Researchers needing the observations do not have to travel to Chajnantor Plateau. Instead, astronomers at ALMA carry out the observations and share the data with researchers remotely. The researchers have exclusive rights to the observation data for one year. After that, the data is made public! Since its opening about five years ago, ALMA has delivered many extraordinary images of the cosmos, including those of:
Protoplanetary disk—a protoplanetary; is a disk of dense gas and dust surrounding a newly formed star which evolves into a planetary system over time. ALMA has contributed largely to the understanding of this process with incredible images of protoplanetary disks around young stars; thereby, greatly transforming our knowledge about the formation of planets.
Einstein’s ring—Einstein predicted that light can bend into a ring by a massive gravitational body. ALMA has been able to capture spectacular images of the rarely observed Einstein ’s ring in unprecedented detail.
Organic molecules—ALMA helped astronomers find complex organic molecules, such as sugars and alcohols, that are necessary to form life, in a protoplanetary disc surrounding a young star. Until now, it was not clear if complex organic molecules can survive in the harsh and energetic environment around the young stars. Using ALMA’s remarkable sensitivity, the astronomers can see now that “these molecules not only survive, but flourish”. The new evidence reaffirms that the conditions which gave birth to the life on earth are not unique in the universe. After all, we may not be alone!
Why are we looking?
Like solving a jigsaw puzzle, ALMA is helping scientists to understand our cosmic origin in the universe bit by bit. We all want to know how we came into existence and what is our position in the universe? This is the deepest question of our lives.
In early astronomy, people identified celestial objects with gods and created many legends. One legend explains how the Milky Way was created by Heracles when he was a baby. His father Zeus brought his infant to Hera to suckle on her milk while she was asleep. When Hera woke up she pushed Heracles away. The drops of spurting milk became the Milky Way.
Later in history, we started making observations of the motion of the Sun and the Moon, invented calendars, and even landed on the moon. But to date, we rely on various religious interpretations to fill gaps in our knowledge about cosmology and its origin. Yet, there is so much we don’t know and cannot explain. Some people say science is anti-religion but philosopher William Lane Craig argued that scientific inquiry presupposes belief in God – required to explain why the universe is intelligible or lawful. What we need is undeniable evidence and scientific explanation of our cosmic origins. If we know where we came from, we might also know where we will go in the future, and why we are here anyway!
The ultimate question is, who we are, and ALMA is helping us find the answer.
As a child, I was always fascinated by astronomy. A large portion of books in my home library was related to astronomy. I bought them all from my pocket savings. Even today, when I am visiting my home in Layyah, Pakistan, I pick up one of the astronomy books from my collection and delve into it for hours.
I am thankful to ALMA for approving my request and providing a one-to-one guided tour. I spent about 6 hours at the observatory. My guide Danilo was very friendly and provided detailed information. He showed me all the important areas at ALMA and even invited me for lunch at the cafeteria, where I had the chance to interact with astronomers.
Danilo told me that I was the first person from Pakistan on a media visit to ALMA. It was indeed a privilege. Thank you!
Here is a short video clip of me talking about my experience at ALMA.
Epilogue: ALMA & Allama
An Urdu poem by Allama Iqbal (Bal-e-Jibril 1935).
ستاروں سے آگے جہاں اور بھی ہیں- ابھی عشق کے امتحاں اور بھی ہیں
More worlds lie beyond the stars, more trials of passion remain
What we see is a limited fragment of existence. The observable universe contains an estimated one to two trillion galaxies. Our own galaxy has about 40 billion earth-sized planets around sun-like stars. There may be even other universes parallel to ours.
تمہی زندگی سے نہیں یہ فضائیں, یہاں سینکڑوں کارواں اور بھی ہیں
Barren, these cosmos are not; a congregation of hundreds of caravans
We appear to be alone in the universe, but ALMA has found organic molecules, the building blocks of life, in the outer space. The is a first step towards detecting the origin of life.
قناعت نہ کر عالمِ رنگ و بو پر -چمن اور بھی ، آشیاں اور بھی ہیں
Be not appeased with the world of colour and fragrance, more gardens, more nests remain
For four centuries, astronomers observed the sky with the visible light. ALMA sees beyond what is visible. With the help of the faint millimetre radio signals of the invisible light cold and hidden stars and galaxies that emerged from the cosmic dark age billions of years ago can be “seen” and studied by the scientists.
اگر کھو گیا اک نشیمن تو کیا غم – مقاماتِ آہ و فغاں اور بھی ہیں
Mourn not the loss of a single domain, Many spaces to long for remain
The more we learn about the cosmos, the more we realise that we do not know. The images captured by ALMA introduce us to parts of space we have not known of.
تو شاہیں ہے ، پرواز ہے کام تیرا – ترے سامنے آسماں اور بھی ہیں
A falcon, flight is your destiny, Ahead of you, vast skies stretched
To soar high and seek further knowledge and answers we must venture forward into unchartered space. Man landed on the moon. Our space probes have gone beyond the solar system. We are now able to observe stars and galaxies, in unprecedented detail.
اسی روز و شب میں الجھ کر نہ رہ جا – کہ تیرے زمان و مکاں اور بھی ہیں
To this day and night, do not be constrained; your space and time are boundless
For centuries tied to the limited concept of time measured by day and dark, we now know that time and space are relative and that Blackholes have the ability to warp spacetime fabric. At ALMA, astronomers were able to measure the precise size of a supermassive blackhole and study a disk of cold interstellar gas circling around it.
گئے دن کہ تنہا تھا میں انجمن میں – یہاں اب مرے رازداں اور بھی ہیں
Gone are the days that I was alone in the congregation, many Confidants abound
Are we alone? The odds are pretty slim. ALAMA has found complex organic molecules in the outer space. The chance that earth is the only planet with life is about 1: 6×1021.