Square Kilometre Array

Exploring the unknown with the world’s largest radio telescope

Here are some highlights of the project:
Countries involved
SKA is an international organisation consisting of 15 member countries, with headquarters at the Jodrell Bank Observatory, near Manchester in the United Kingdom. Member countries include Australia, Canada, China, India, Italy, France, Germany, New Zealand, Portugal, South Africa, Spain, Sweden, Switzerland, the Netherlands and the United Kingdom. Further countries have expressed their interest in joining the SKA Organisation, which will continue to expand.
Development
The development of SKA will use the results of various surveys undertaken using another powerful telescope called the Australian Square Kilometre Array Pathfinder (ASKAP).
ASKAP is developed and operated by Australia’s science agency Commonwealth Scientific and Industrial Research Organisation (CSIRO).
This telescope, which has been fully operational since February 2019, mapped over three million galaxies in a record 300 hours during its first all-sky survey conducted late last year.
ASKAP surveys are designed to map the structure and evolution of the Universe, which it does by observing galaxies and the hydrogen gas that they contain.
Sites
The gigantic project has one site in Australia, another in South Africa
1. Australian Site
Australia will host SKA-Low that will operate between 50 and 350 megahertz.
When SKA-Low is complete, it will comprise 131,072 antennas spread between 512 stations. The furthest antennas will be 65 kilometres away from each other throughout the desert. However, because of the way the telescope works, research will be done after the first few stations are built.
Once completed, the SKA-Low will be significantly more powerful than any other radio telescopes of this type – potentially up to eight times as sensitive and 135 times faster than comparable current telescopes.
2. South African Site
South Africa will host SKA-Mid that will consist of 197 parabolic dish antennas, with a maximum baseline of 120 km and operate between 350 megahertz and about 15 gigahertz. The first 64 dishes are 13.5 metres in diameter and used for the pathfinder telescope MeerKAT and the remainder will be 15 m in diameter.
The SKA-Mid looks more like a series of ‘normal’ dish telescopes. It will observe a higher frequency of the radio spectrum, but being relatively close together in the same hemisphere, they will regularly see the same sky and can be used together in certain situations.
Operating Frequency
The system’s operating frequency range will be from about 50 megahertz to 25 gigahertz. This range will allow the telescope to catch very faint radio signals from cosmic sources that are billions of light-years from Earth. This includes the signals caused during the initial few hundred million years after the Big Bang.
Cost
The total budget for construction is €2 billion, and the amount spent to date will be just under €500 million as soon as the contracts are finalized.
What will it do?
The SKA will allow astronomers to look deeper into the universe and unravel secrets about its evolution. Among its goals are: studying the universe and its evolution, the origin and evolution of cosmic magnetism, and dark energy and evolution of galaxies. Scientists are also optimistic that the SKA will be able to detect very weak extra-terrestrial signals and search for molecules that support life.
Significance
Twentieth-century astronomers discovered an expanding universe with billions of galaxies, each filled with billions of stars, along with exotic objects such as black holes, quasars and neutron stars. A major challenge for the next century is to understand how it all got there and how it has evolved. To this end, astronomers have identified the following key science goals for the SKA.
· The beginning of the universe.
· How and when the first stars were born.
· The life-cycle of a galaxy.
· Exploring the possibility of detecting technologically-active civilisations elsewhere in our galaxy.
· Understanding where gravitational waves come from.
· Clarify the nature of both dark energy and dark matter
· Map the magnetic fields within the Milky Way and beyond
· Find what these magnetic fields look like, their origin, and their role in the evolving universe.
· carry out more rigorous tests of Einstein’s theory of general relativity
· As per NASA, the telescope will accomplish its scientific goals by measuring neutral hydrogen over cosmic time, accurately timing the signals from pulsars in the Milky Way, and detecting millions of galaxies out to high redshifts.
Although the SKA has these well-defined science goals, it is possible that its most important discoveries will be unexpected—completely new phenomena and new laws of physics.
The universe is big. The SKA will enable us to see right to its edges. Who can tell what we might find there!