Square Kilometre Array

Square Kilometre Array
Name	Square Kilometre Array
Caption	Logo of the Square Kilometre Array Observatory
Organization	SKA Observatory
Location	Murchison Radio-astronomy Observatory, Australia and Karoo, South Africa
Wavelength	Radio, 50 MHz to 15 GHz
Built	2021–present (Phase 1)
Website	https://www.skao.int/

Square Kilometre Array. It is an intergovernmental radio telescope project designed to be the world's most sensitive astronomical observatory. The facility is being constructed across two remote sites in the Southern Hemisphere: the Murchison Radio-astronomy Observatory in Western Australia and the Karoo region in South Africa. Upon completion, its vast collecting area, spanning over a square kilometre, will enable unprecedented studies of the universe, from testing Einstein's theory of general relativity to investigating the origins of the first stars and galaxies.

Overview

The project represents a monumental leap in scale and capability for radio astronomy, coordinated by the SKA Observatory, an international organisation headquartered at the Jodrell Bank Observatory in the United Kingdom. Unlike a single dish, it comprises thousands of individual antennas and dishes working in unison as an interferometer, creating an exceptionally high-resolution virtual telescope. This design allows it to survey the sky over ten thousand times faster than current instruments, making it a cornerstone for 21st century astrophysics. Its development has driven significant advances in big data computing, renewable energy solutions, and fibre-optic communication networks to handle the immense data streams it will produce.

Design and specifications

The telescope's design is split into two distinct components, each optimized for different frequency ranges. The SKA-Low array in Australia will consist of over 130,000 dipole antennae sensitive to frequencies between 50 and 350 MHz, designed to detect the faint signals from the Epoch of Reionization. The SKA-Mid array in South Africa will feature nearly 200 parabolic reflector dishes, including those of the existing MeerKAT array, operating from 350 MHz to over 15 GHz. Together, these arrays will generate data at a rate exceeding the global internet traffic, processed by supercomputers at sites like the Pawsey Supercomputing Centre in Perth.

Location and construction

The selected sites offer exceptional radio quietness, protected by national legislation such as South Africa's Astronomy Geographic Advantage Act. Construction of Phase 1 began in late 2021 following the signing of the SKA Observatory Convention. The Australian site, located on the traditional lands of the Wajarri Yamaji people, will host the SKA-Low array. The South African site, adjacent to the MeerKAT telescope in the Karoo, will host the SKA-Mid dishes. Major infrastructure work includes installing thousands of kilometres of fibre optic cable and building custom-designed signal processing facilities to correlate signals from the widely separated antennas.

Science goals and key projects

Its primary science goals are outlined in detailed key projects developed by international teams. These include tracing the history of cosmic dawn and the formation of the first stars, mapping the structure of the cosmic web through neutral hydrogen emissions, and probing the nature of gravity and dark energy. It will also conduct vast surveys to study the Milky Way in detail, detect pulsars to create a galactic-scale gravitational wave detector, and search for complex organic molecules that could hint at the building blocks of life beyond Earth. Observations may also contribute to the Search for extraterrestrial intelligence.

Participating countries and organisations

The project is governed by the SKA Observatory, whose member countries as of 2023 include Australia, South Africa, the United Kingdom, Italy, the Netherlands, Portugal, Switzerland, and Canada, with several other nations like France, Germany, India, Japan, South Korea, and Sweden engaged as observers or through bilateral agreements. Key partner organisations contributing technology and expertise include the Commonwealth Scientific and Industrial Research Organisation, the South African Radio Astronomy Observatory, the Istituto Nazionale di Astrofisica, and the National Research Council (Canada).

History and timeline

The concept was first proposed in the early 1990s by an international consortium of astronomers. Major development phases included the formation of the SKA Organisation in 2011, the critical site selection decision in 2012 favouring the dual-site model, and the detailed design work completed in the 2010s. The founding treaty, the SKA Observatory Convention, entered into force in January 2021, establishing the permanent intergovernmental organisation. First light for Phase 1 is anticipated in the late 2020s, with full operational capability for the complete design envisioned for the 2030s, following further construction phases dependent on funding and technological readiness.

Category:Radio telescopes Category:International scientific organizations Category:Astronomical observatories in South Africa Category:Astronomical observatories in Australia