Tuesday, March 5, 2024

Construction begins on the world’s largest radio observatory

After 30 years of planning and negotiations, the construction of the world’s largest radio astronomy observatory, the Square Kilometre Array (SKA), has officially begun in Australia and South Africa.

The SKA telescope will initially be made up of 131,072 antennas in Australia (SKA-Low) and 197 dishes in South Africa (SKA-Mid). It will provide an unparalleled view of the Universe and be one of the biggest science facilities on Earth. The giant instrument will collect the radio signals emitted by celestial objects and will hopefully shed light on some of the most enigmatic problems in astronomy, such as the nature of dark matter and how galaxies form.

The large distances between antennas, and their sheer number, mean that the telescopes will pick up radio signals with unprecedented sensitivity. SKA-Low will detect frequencies between 50 megahertz and 350 megahertz, and SKA-Mid will pick up frequencies between 350 megahertz and 15.4 gigahertz.

“The SKA Observatory’s telescopes will be one of humanity’s biggest-ever scientific endeavors. I have been involved with the SKA project for the past 30 years, so to finally see the start of on-site construction is a momentous occasion,” SKAO Director-General Professor Philip Diamond said.

Among many scientific goals, the SKA-Low will explore the first billion years after the so-called ‘dark ages’ of the Universe, when the first-ever stars and galaxies were forming. It will map the structure of the infant Universe for the first time, enabling scientists to watch the births and deaths of the first stars and help us to understand how the earliest galaxies formed.

The SKA telescopes’ sheer size and a number of antennas mean they will provide a significant leap in sensitivity, resolution, and survey speed. The telescopes will be able to see the sky more clearly, reveal fainter details, and see more of the sky at once than other state-of-the-art telescopes. SKA-Low will be eight times as sensitive and will map the sky 135 times faster than comparable current telescopes.

“To put the sensitivity of the SKA into perspective, the SKA could detect a mobile phone in the pocket of an astronaut on Mars, 225 million kilometers away,” said Senior Postdoctoral Fellow at Australia’s Curtin Institute of Radio Astronomy, Dr. Danny Price. “More excitingly, if there are intelligent societies on nearby stars with technology similar to ours, the SKA could detect the aggregate ‘leakage’ radiation from their radio and telecommunication networks – the first telescope sensitive enough to achieve this feat.”

“The tremendous sensitivity of the SKA will allow astronomers to peer back billions of years to ‘Cosmic Dawn’: the epoch when the first stars in the Universe were forming. From searching for extraterrestrial intelligence (SETI) to detecting signals from Cosmic Dawn, there are so many exciting science questions the SKA will answer. We are going to need more astronomers, engineers, and data scientists!”