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Key Takeaways
- SKAO constructs the world’s largest radio telescope network
- Dual locations chosen in South Africa and Australia
- Scientific focus covers cosmic dawn, pulsars, and life origins
Introduction to the Square Kilometre Array
The Square Kilometre Array (SKA) represents a massive leap forward in the field of radio astronomy. It is an international effort to construct the world’s largest radio telescope, featuring a total collecting area of approximately one square kilometer. This vast collecting surface is not a single dish but a combination of thousands of dishes and up to a million low-frequency antennas distributed across two continents. The scale of the project exceeds any previous astronomical facility, designed to provide sensitivity, resolution, and survey speeds that far outstrip existing capabilities.
The project is governed by the Square Kilometre Array Observatory (SKAO), an intergovernmental organization with its headquarters at the Jodrell Bank Observatory in the United Kingdom. The telescopes reside in two of the most radio-quiet regions on Earth: the Karoo region in South Africa and the Murchison region in Western Australia. These remote locations allow the observatory to minimize interference from human-made radio signals, such as FM radio, television broadcasts, and mobile phone networks. This silence is necessary for detecting the faint radio signals from the distant universe.
The scientific possibilities of the SKA are extensive. It enables astronomers to observe the earliest moments of the universe, shortly after the Big Bang, to witness the formation of the first stars and galaxies. It will test fundamental laws of physics, specifically General relativity, in the extreme environments surrounding pulsars and black holes. The telescope will also explore the evolution of magnetism in the cosmos and search for the building blocks of life in protoplanetary disks, potentially detecting signals from extraterrestrial civilizations.
Unlike optical telescopes that observe visible light, the SKA observes radio waves. These waves possess much longer wavelengths than visible light, allowing them to pass through dust and gas that obscure many objects in the universe. This capability enables astronomers to study the “invisible” universe, revealing structures and processes that remain hidden from view. The SKA serves as a next-generation facility intended to operate for at least 50 years, driving scientific discovery and technological innovation for decades.
The Fundamentals of Radio Astronomy
To understand the SKA, it is helpful to examine the principles of radio astronomy. Radio astronomy involves the study of celestial objects that emit radio waves. Radio waves are a form of electromagnetic radiation, similar to visible light, X-rays, and ultraviolet light, but with much lower frequencies and longer wavelengths. While visible light wavelengths measure in hundreds of nanometers, radio waves range from less than a millimeter to many kilometers.
Celestial bodies emit radio waves through various physical mechanisms. Thermal emission happens when charged particles in a hot gas accelerate, releasing energy. Non-thermal emission, such as synchrotron radiation, occurs when electrons spiral in magnetic fields at speeds approaching the speed of light. This type of radiation appears frequently in supernova remnants, pulsars, and the jets of active galactic nuclei. Another specific type of emission is the spectral line, which occurs when atoms or molecules transition between energy states. The most well-known of these is the 21-centimeter line of Neutral particle hydrogen, which allows astronomers to map the distribution of gas in galaxies and the universe.
A single radio dish functions much like a bucket collecting rain; a larger dish collects more radio waves and detects fainter signals. However, constructing a single dish one kilometer in diameter is structurally impossible with current materials. To overcome this limitation, radio astronomers use a technique called Interferometry. This method involves linking multiple smaller antennas together to function as a single, giant telescope.
The distance between the furthest antennas in an array is the baseline. The length of the baseline dictates the resolution of the telescope – its ability to distinguish fine details. The total surface area of all the antennas combined determines the sensitivity – how faint a signal it can detect. The SKA utilizes interferometry on a massive scale, connecting thousands of receptors over distances extending hundreds of kilometers. The signals from each antenna combine in a central supercomputer called a correlator, which processes the data to create high-resolution images of the sky. This technique allows the SKA to achieve a resolution far sharper than that of the Hubble Space Telescope, despite operating at much longer wavelengths.
Historical Context and Project Origins
The concept of a square kilometer array emerged in the early 1990s. Astronomers recognized that existing radio telescopes were reaching their limits regarding sensitivity and resolution. To answer the next generation of fundamental questions in astrophysics, they required a telescope with a collecting area roughly 100 times larger than the Very Large Array (VLA) in the United States. In 1993, the International Union of Radio Science established the Large Telescope Working Group to begin initial planning for such a facility.
Over the next two decades, the project evolved from a concept into a detailed engineering design. Key milestones included the signing of the first Memorandum of Understanding in 2000, which established the International SKA Steering Committee. In the years that followed, countries around the world joined the effort, contributing funding and expertise. A major decision point occurred in 2012 when the site selection committee had to choose between two bids: one from Australia and New Zealand, and another from a consortium of African countries led by South Africa.
The decision involved splitting the project between the two primary sites. South Africa would host the mid-frequency component of the telescope, while Australia would host the low-frequency component. This dual-site strategy allowed the project to leverage the specific environmental and geographical advantages of both locations. It also maximized political and financial support for the project by involving a wider range of international partners.
In 2021, the Square Kilometre Array Observatory officially launched as an intergovernmental organization (IGO), similar in structure to CERN or the European Space Agency. This provided the project with a stable legal and financial framework, allowing it to award contracts and hire staff. Construction activities officially commenced on December 5, 2022, marking the transition from design to physical reality.
The Structure of the SKAO
The Square Kilometre Array Observatory is the body responsible for overseeing the construction and operation of the telescopes. As an intergovernmental organization, it operates under a treaty negotiated by the member states. The observatory’s headquarters are located at Jodrell Bank Observatory in Cheshire, United Kingdom, a site with a long history in radio astronomy.
The governance structure consists of a Council, which includes representatives from each member country. The Council is the supreme decision-making body, responsible for approving the budget, strategic direction, and admission of new members. The Director-General leads the daily operations of the observatory.
The member states form the core of the project. As of late 2025, the founding members include Australia, China, Italy, the Netherlands, Portugal, South Africa, and the United Kingdom. Several other nations have since joined or are in the process of acceding to the convention, including France, Spain, Switzerland, Germany, and Canada. Countries such as Japan, South Korea, and India serve as observers or contributors, providing significant technical and scientific input.
Funding for the SKA comes from the member states, with contributions determined by a formula based on economic capacity and scientific interest. The total cost of construction and the first decade of operations involves billions of euros. This shared investment model ensures that no single country bears the full financial burden, while all members gain access to the telescope time and the resulting scientific data.
SKA-Low: The Australian Site
The low-frequency component of the observatory, known as SKA-Low, is located at Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory in Western Australia. This region is sparsely populated, resulting in exceptionally low levels of radio frequency interference. It is one of the few places on Earth where the radio sky is observable in a near-pristine state.
SKA-Low does not use traditional dishes. Instead, it utilizes log-periodic dipole antennas, which resemble metallic Christmas trees standing about two meters tall. These antennas are simple in mechanical design but sophisticated in their electronic capability. They have no moving parts and are steered electronically to look at different parts of the sky. This design allows for rapid scanning and the ability to observe multiple fields of view simultaneously.
In the first phase of construction, SKA-Low will consist of 131,072 antennas. These are grouped into 512 stations, with each station containing 256 antennas. The stations follow a specific configuration: a dense core to provide high sensitivity and spiral arms extending outwards to provide high resolution. The maximum baseline for SKA-Low is approximately 65 kilometers.
SKA-Low operates in the frequency range of 50 MHz to 350 MHz. This frequency band is important for studying the early universe. Specifically, it targets the redshifted 21-centimeter signal from neutral hydrogen gas that existed before the first stars formed. By mapping this signal, SKA-Low creates a timeline of the universe evolving from the Dark Ages to the Cosmic Dawn.
Progress on SKA-Low has been steady. By August 2025, the first four stations, comprising over 1,000 antennas, were operational and successfully verifying data. This milestone demonstrated that the complex signal processing chain, which must combine signals from thousands of antennas in real-time, functions as designed.
SKA-Mid: The South African Site
The mid-frequency component, SKA-Mid, is located in the Karoo region of South Africa’s Northern Cape province. Like the Australian site, the Karoo is a semi-desert region with very low population density and minimal radio interference. The site operates as a radio astronomy reserve, protected by legislation to prevent the proliferation of radio-transmitting devices in the area.
SKA-Mid utilizes dish antennas, which are more familiar to the general public. These dishes are offset Gregorian designs, meaning the sub-reflector is positioned out of the main signal path to reduce blockage and increase sensitivity. Each dish is 15 meters in diameter and composed of high-precision panels.
The full SKA-Mid array will eventually comprise 197 dishes. This number includes 133 new SKA dishes and the 64 existing dishes of the MeerKAT telescope, which acts as a precursor and will integrate into the final array. The integration of MeerKAT adds significant collecting area and proven technology to the system. The dishes are spread across the Karoo, with a dense core and spiral arms extending up to 150 kilometers.
SKA-Mid operates across a wide frequency range, initially from 350 MHz to 15.4 GHz, with plans to expand up to 20 GHz or higher in future phases. This range covers many essential spectral lines and continuum emissions. SKA-Mid serves as the primary instrument for studying pulsars, testing theories of gravity, and mapping the distribution of galaxies across cosmic time.
Construction progress in South Africa has also been significant. The first dish structure arrived on site in early 2024, and the first receiver was installed in July 2025. This receiver successfully detected its first astronomical signal shortly thereafter, validating the optical and electronic design of the new dishes.
Precursor Telescopes: MeerKAT and ASKAP
Before the construction of the full SKA began, the host countries built precursor telescopes to test the technology and the sites. These precursors are powerful scientific instruments in their own right and have already made major discoveries.
MeerKAT:
Located in South Africa, MeerKAT consists of 64 interlinked receptors. It is currently one of the most sensitive radio telescopes in the world. Since its inauguration in 2018, it has produced clear images of the galactic center, revealing filamentary structures that suggest complex magnetic activity.
In March 2024, an international team using MeerKAT discovered 49 new gas-rich galaxies in a single observation lasting less than three hours. This discovery highlighted the telescope’s survey speed. In early 2025, MeerKAT helped identify “Inkathazo,” a giant radio galaxy with plasma jets extending 3.3 million light-years, challenging current models of how such massive structures form. MeerKAT also played a key role in identifying “Kyklos,” an Odd Radio Circle (ORC) that resembles a smoke ring in space, the origin of which remains a subject of debate.
ASKAP:
The Australian Square Kilometre Array Pathfinder (ASKAP) is located at the Murchison site. It features 36 dishes, each equipped with a phased array feed. This technology effectively puts “radio sunglasses” on the telescope, giving it a massive field of view. ASKAP can map the entire southern sky rapidly.
ASKAP has become a leader in the detection of Fast radio burst (FRBs) – millisecond-long flashes of radio energy from distant galaxies. It has not only found many of these bursts but has also pinpointed their host galaxies, helping astronomers use them as cosmic weighing scales to measure the density of the universe. In May 2025, ASKAP discovered a mysterious object named ASKAP J1832-0911, which flashes in both radio and X-rays, a behavior that does not fit neatly into existing categories of neutron stars or magnetars.
Other pathfinders include the Murchison Widefield Array (MWA) in Australia, which focuses on low-frequency solar and ionospheric science, and the Hydrogen Epoch of Reionization Array (HERA) in South Africa, dedicated to the specific signature of the cosmic dawn.
Scientific Objective: The Cosmic Dawn
One of the primary drivers for building the SKA is the desire to understand the history of the universe’s first light. After the Big Bang, the universe expanded and cooled, entering a period known as the Dark Ages. During this time, the cosmos was filled with neutral hydrogen gas, but there were no stars or galaxies to light it up.
Eventually, gravity pulled pockets of gas together to form the very first stars. These stars were likely massive and short-lived, emitting intense ultraviolet radiation. This radiation interacted with the surrounding hydrogen, stripping away electrons in a process called reionization. This era is known as the Epoch of Reionization.
SKA-Low is designed specifically to observe this epoch. Neutral hydrogen emits a radio signal at a wavelength of 21 centimeters. Because the universe is expanding, this signal is stretched (redshifted) to longer wavelengths (lower frequencies) by the time it reaches Earth. By tuning into these low frequencies, SKA-Low can map the distribution of hydrogen during the Dark Ages and the Epoch of Reionization.
The goal is to see the “bubbles” of ionized gas created by the first stars and galaxies as they turned on and cleared the fog of neutral hydrogen. This observation provides direct evidence of how structure formed in the infant universe and will help refine the timeline of cosmic history.
Scientific Objective: Galaxy Evolution and Cosmology
Galaxies are the fundamental building blocks of the visible universe, but how they form and evolve presents a complex puzzle. The SKA conducts massive surveys of the sky to map the distribution of millions of galaxies. It will look at the neutral hydrogen content of galaxies, which serves as the fuel for star formation.
By observing galaxies at different distances (and thus different times in history), the SKA will reveal how the gas content of the universe has changed over billions of years. It will show how galaxies acquire gas from their surroundings, how they convert it into stars, and how they eject it back into intergalactic space through supernova explosions and active black holes.
These surveys also have major implications for cosmology. By mapping the positions of millions of galaxies, the SKA will measure the expansion rate of the universe with high precision. This will help constrain the properties of Dark energy, the mysterious force that is accelerating the expansion of the cosmos. The SKA will also test models of Dark matter by measuring the rotation curves of galaxies out to much greater distances than currently possible.
Scientific Objective: Pulsars and General Relativity
Pulsars are rapidly rotating neutron stars – the collapsed cores of massive stars that have exploded as supernovae. They are incredibly dense and possess strong magnetic fields. As they spin, they emit beams of radio waves that sweep across the sky like a lighthouse beam. When these beams cross Earth, we detect a regular pulse.
Pulsars are nature’s most accurate clocks. Some spin hundreds of times per second with a stability comparable to atomic clocks. The SKA will discover thousands of new pulsars, including those in the center of our galaxy, which are currently hidden by dust.
One of the most exciting applications of pulsar timing is the detection of Gravitational waves. As gravitational waves from supermassive black hole binaries pass through the galaxy, they stretch and squeeze spacetime. This distortion changes the arrival times of pulsar pulses by a tiny amount. By monitoring an array of stable pulsars (a Pulsar Timing Array), the SKA will detect this background hum of gravitational waves, opening a new window onto the universe distinct from the high-frequency waves detected by LIGO and Virgo.
Furthermore, finding a pulsar orbiting a black hole would provide the ultimate test laboratory for Einstein’s theory of General Relativity. Astronomers could measure how the strong gravity of the black hole affects the pulsar’s signal, testing the theory in the strongest gravitational fields ever probed.
Scientific Objective: Cosmic Magnetism
Magnetism is pervasive in the universe, affecting the evolution of stars and galaxies, yet its origins remain one of the least understood areas of astrophysics. Magnetic fields are difficult to observe directly. Radio astronomy offers a unique tool called Faraday rotation.
When polarized radio waves pass through a magnetic field, their plane of polarization rotates. The amount of rotation depends on the strength of the magnetic field. By measuring this rotation for millions of distant radio sources, the SKA will create a 3D map of the magnetic universe.
This “Cosmic Magnetism” project seeks to answer where magnetic fields came from. were they primordial, created in the Big Bang? Or were they generated later by dynamo processes within stars and galaxies? Understanding magnetism is necessary because magnetic fields play a key role in regulating star formation and shaping the structure of the interstellar medium.
Scientific Objective: The Cradle of Life
The question of whether we are alone in the universe is one of the most significant inquiries of humanity. The SKA will contribute to the search for life in several ways.
First, it will study the formation of planetary systems. It will observe the thermal emission from dust in protoplanetary disks – the swirling disks of material around young stars where planets are born. Specifically, the SKA will look for large “pebbles” of dust, which are the seeds of rocky planets like Earth.
Second, the SKA will search for prebiotic molecules. Radio telescopes can identify specific molecules in space by their spectral fingerprints. The SKA will look for complex organic molecules, such as amino acids, in the interstellar medium and in planet-forming regions.
Third, the SKA conducts the most sensitive search ever for Search for extraterrestrial intelligence (SETI). It will scan the sky for “technosignatures” – radio signals that could only be produced by artificial technology. The SKA will be sensitive enough to detect an airport radar on a planet dozens of light-years away. This capability significantly expands the volume of space in which we can listen for neighbors.
The Big Data Challenge
The SKA is as much an IT project as it is a physics project. The amount of data generated by the antennas is staggering. In the case of SKA-Low, the raw data rate from the antennas to the on-site signal processors is measured in petabits per second – more than the entire global internet traffic.
This data cannot be stored; it must be processed in real-time. The Central Signal Processor (CSP) reduces this flood of data by combining signals and averaging them, but the output is still massive. The Science Data Processor (SDP) then takes this data and produces astronomical images and catalogs. The expected archive growth is approximately 700 petabytes per year.
To handle this, the Square Kilometre Array Observatory is establishing a network of SKA Regional Centres (SRCs) located in member countries. These centers will host the data and provide the computing power for astronomers to analyze it. This creates a “cloud” model for astronomy, where the scientist does not download the data to their laptop but instead sends their analysis code to the data center.
Canada, for instance, is establishing a Regional Centre to serve the Americas. These centers require cutting-edge high-performance computing (HPC) and artificial intelligence algorithms to sort through the noise and find the signals. The technology developed to handle SKA data will likely have spin-off applications in other fields dealing with big data, such as medical imaging and climate modeling.
Environmental and Cultural Considerations
Building such massive infrastructure in remote locations requires careful consideration of the environment and the local communities. The SKAO has committed to sustainable construction practices. The remote sites are often off the grid, requiring independent power solutions. There is a strong focus on using renewable energy, specifically solar farms with battery storage, to power the telescopes and minimize radio interference caused by power transmission lines.
Cultural heritage is also a priority. In Australia, the Murchison site is on the traditional lands of the Wajarri Yamaji people. The project has engaged in consultation with the indigenous owners to ensure that construction respects sacred sites and cultural landscapes. An Indigenous Land Use Agreement (ILUA) is in place, providing benefits to the local community, including jobs, education, and infrastructure.
Similarly, in South Africa, the project engages with the local communities in the Karoo. The observatory invests in education programs, providing bursaries for students to study science and engineering. The goal is to ensure that the telescope is not just a scientific instrument but a driver for development in the regions where it is hosted.
Timeline and Future Phases
The construction of the SKA is a phased process. The current phase, often referred to as Phase 1, involves the installation of the 131,072 low-frequency antennas in Australia and the 197 dishes in South Africa. Construction began in December 2022 and is expected to be completed towards the end of the decade, around 2029 or 2030.
However, science commissioning begins much earlier. Because the SKA is an interferometer, it can start doing science as soon as a small subset of antennas is connected. This “early science” phase allows astronomers to begin using the instrument while it is still growing. We have already seen this with the verification of the first SKA-Low stations in 2025.
Beyond Phase 1, there is a vision for a Phase 2, which would expand the array significantly. This could involve increasing the number of dishes in South Africa to over 2,000 and spreading them across other African partner countries such as Botswana, Ghana, Kenya, Madagascar, Mauritius, Mozambique, Namibia, and Zambia. This expansion would increase the baseline to thousands of kilometers, providing even higher resolution (Very Long Baseline Interferometry). In Australia, Phase 2 would involve increasing the number of low-frequency antennas to over a million. While Phase 2 is currently a future aspiration dependent on funding and the success of Phase 1, the design of the observatory allows for this scalability.
Economic and Technological Spin-offs
Large scientific projects often drive innovation in unexpected ways. The requirements of the SKA push the boundaries of what is possible in engineering, computing, and data transmission.
Development in low-power electronics is necessary to process the signals from thousands of antennas without generating excessive heat or radio noise. Innovations in fiber optic data transmission are required to move the massive volumes of data over long distances in the desert. The algorithms developed to process the data are advancing the fields of machine learning and artificial intelligence.
These technologies have commercial potential. For example, the signal processing techniques used in radio astronomy have previously been applied to improve Wi-Fi protocols and medical imaging devices like MRI scanners. The investment in the SKA fosters a high-tech ecosystem in the member countries, creating jobs for engineers, data scientists, and technicians.
Summary
The Square Kilometre Array is more than just a telescope; it is a global scientific platform that unites nations in the pursuit of knowledge. By combining the vast collecting area of sites in Australia and South Africa, the SKA provides humanity with the most detailed radio map of the universe ever constructed.
From the moment the first stars ignited in the Cosmic Dawn to the subtle warping of spacetime by gravitational waves, the SKA will observe phenomena that define the history and physics of our cosmos. With construction well underway and initial milestones already achieved in 2025, the era of the SKA has arrived. The data it produces in the coming decades will likely rewrite textbooks and answer questions we have not yet learned to ask.
As the Square Kilometre Array Observatory continues its work, it serves as a testament to what can be achieved when the world collaborates on a shared vision of discovery. The silence of the Karoo and the Murchison is about to be filled with the sounds of the universe, revealing secrets that have been waiting for billions of years to be heard.
Appendix: Top 10 Questions Answered in This Article
What is the Square Kilometre Array (SKA)?
The SKA is an international project to build the world’s largest radio telescope, with a total collecting area of one square kilometer. It consists of thousands of dishes and antennas located in South Africa and Australia.
Why are there two different sites for the SKA?
The project uses a dual-site strategy to leverage the optimal environmental conditions of both the Karoo region in South Africa and the Murchison region in Australia. Each site hosts a different type of instrument: dishes for mid-frequency signals in South Africa and dipole antennas for low-frequency signals in Australia.
What is the difference between SKA-Mid and SKA-Low?
SKA-Mid uses dish antennas to detect higher frequency radio waves (350 MHz to 15.4 GHz) and is located in South Africa. SKA-Low uses log-periodic dipole antennas to detect lower frequency radio waves (50 MHz to 350 MHz) and is located in Australia.
When did construction of the SKA begin?
Official construction ceremonies took place on December 5, 2022, at both the South African and Australian sites. This marked the transition from the design and planning phase to the actual physical build of the telescopes.
Who manages the SKA project?
The project is managed by the Square Kilometre Array Observatory (SKAO), an intergovernmental organization headquartered at Jodrell Bank in the United Kingdom. The SKAO oversees the construction, operations, and governance of the telescope.
What are the main scientific goals of the SKA?
The primary goals include studying the Epoch of Reionization (Cosmic Dawn), testing General Relativity using pulsars, mapping cosmic magnetism, understanding galaxy evolution, and searching for extraterrestrial life or the origins of life.
How does the SKA handle the massive amount of data it produces?
The SKA uses a network of Regional Centres (SRCs) distributed globally to process and store the data. It relies on advanced high-performance computing and artificial intelligence to reduce the raw data volume, which exceeds global internet traffic rates, into usable scientific products.
What are precursor telescopes?
Precursor telescopes like MeerKAT in South Africa and ASKAP in Australia were built to test the technology and sites before the full SKA construction. They are fully functional scientific instruments that have already made significant discoveries and will be integrated into the final array.
Does the SKA search for aliens?
Yes, one of the scientific objectives is the search for extraterrestrial intelligence (SETI). The SKA’s high sensitivity allows it to detect very faint leakage radiation, such as airport radars, from planets dozens of light-years away, as well as searching for prebiotic molecules.
What is the “Cosmic Dawn”?
The Cosmic Dawn is the period in the early universe when the first stars and galaxies formed, ending the cosmic “Dark Ages.” SKA-Low is specifically designed to detect the neutral hydrogen signal from this era to understand how the universe lit up.
Appendix: Top 10 Frequently Searched Questions Answered in This Article
Where is the SKA telescope located?
The SKA is located in two primary sites: the Murchison region of Western Australia (for low frequencies) and the Karoo region of South Africa (for mid frequencies). These remote locations were chosen for their radio quietness.
How much does the Square Kilometre Array cost?
The total cost for construction and the first ten years of operation is estimated to be several billion euros. The funding is shared among the member nations of the SKAO based on an agreed formula.
What countries are members of the SKA?
Founding members include Australia, China, Italy, the Netherlands, Portugal, South Africa, and the United Kingdom. Other countries like France, Spain, Switzerland, Germany, and Canada have joined or are in the process of joining.
How does a radio telescope work?
Radio telescopes detect radio waves emitted by celestial objects using antennas or dishes. These signals are amplified and processed by computers to create images or spectra, revealing information that is invisible to optical telescopes.
What is interferometry in the context of the SKA?
Interferometry is a technique that links multiple antennas together to act as a single, giant telescope. This allows the SKA to achieve a resolution and sensitivity equivalent to a single dish that is kilometers wide, which would be impossible to build physically.
What are the benefits of the SKA for the general public?
Beyond scientific discovery, the SKA drives innovation in big data, computing, and green energy. It also creates jobs, supports local education in host countries, and fosters international cooperation.
How long will the SKA take to build?
Construction started in late 2022 and is expected to be completed around 2029 or 2030. However, the telescope will begin producing scientific data before construction is fully finished through a process of staged commissioning.
What is the 21cm line?
The 21cm line is a specific radio wavelength emitted by neutral hydrogen atoms. It is the primary tool used by radio astronomers to map the distribution of gas in the universe, from nearby galaxies to the very early universe during the Cosmic Dawn.
Can the SKA detect gravitational waves?
Yes, the SKA will detect gravitational waves by monitoring Pulsar Timing Arrays. It will measure tiny irregularities in the arrival times of pulses from millisecond pulsars caused by the passage of gravitational waves through spacetime.
What is the difference between the SKA and the James Webb Space Telescope?
The James Webb Space Telescope observes the universe in infrared light from space, while the SKA observes radio waves from the ground. They are complementary instruments; observing the same objects in different wavelengths provides a more complete picture of the physics involved.
