The world’s largest radio telescope allows us to investigate the most profound questions science seeks to answer. How did life begin? What is dark matter? What is the universe made of? And perhaps the most fascinating of all – are we alone?
Radio telescopes serve as our gateway to the universe’s deeper layers. Their immense size amplifies their sensitivity, enabling them to catch the faintest signals originating from light-years away. Despite their monumental scale, they are extraordinarily complex, embodying precise engineering and sophisticated computing technologies.
The world’s largest radio telescopes, including the biggest radio telescope ever built, are instrumental in expanding the boundaries of our knowledge and understanding of space and time.
Let’s look at the biggest radio telescopes in the world, the invaluable tools that connect us to the hidden realm of the cosmos.
The Different Types of Radio Telescopes
There are two main types of radio telescope – single-dish radio telescopes and interferometer array radio telescopes.
Single-dish radio telescopes are large dish-shaped antennas that detect and magnify radio signals from space. They gather signals and focus them onto a receiver similar to the way a satellite dish works. They can pick up weak signals, but their resolution is limited by the physical size of the dish.
An interferometer works by combining signals from multiple, smaller telescopes. This dramatically improves the resolution compared to a single dish, allowing for far more detailed observations. The main drawback is that these arrays are more complex and expensive to build and operate than single-dish telescopes.
This article is focused on the world’s largest single-dish radio telescopes, culminating in the world’s largest radio telescope.
Sardinia Radio Telescope
Location: Sardinia, Italy | Diameter: 64 metres | First light: 2012
Weighing 3,300 tonnes, the €70 million Sardinia Radio Telescope, or SRT, is a collaboration between the Istituto di Radioastronomia di Bologna, the Cagliari Observatory and the Arcetri Astrophysical Observatory in Florence. The latter is close to the seventeenth century home of Galileo. One of the world’s largest radio telescopes, it is fully steerable with 1,116 actuators and is used for, amongst other things, deep space communication exploration.
DSS 14 ‘Mars’
Location: California, USA | Diameter: 70 metres | Built: 1958
Deep Space Station, or DSS 14, is part of the Goldstone Deep Space Communications Complex at Fort Irwin. The fundamental purpose of one of the biggest radio telescopes in the world is to track and communicate with NASA’s space missions. The ‘Mars’ antenna earned its name because it was used to track the Mariner 4 spacecraft, which performed the first successful flyby of Mars in 1965. Since then, it has provided vital communication links to many missions, including those to Mars, Venus, Jupiter, and beyond. It has also been used in the Search for Extraterrestrial Intelligence (SETI).
Location: Cheshire, UK | Diameter: 76 metres | First light: 1957
Named after Bernard Lovell, the first director of the Jodrell Bank Observatory where the telescope lives, the biggest radio telescope ever built in the UK has been in constant use for almost seventy years. It was built at a cost of £700,000 – a fortune in post-war Britain – and soon after it became operational in 1957, it was used to track the booster rocket for Sputnik, the world’s first artificial satellite. In 2005, astronomers using the Lovell Telescope discovered VIRGOHI21, a region of neutral hydrogen in the Virgo constellation made up of a large amount of dark matter. It is similar in size to 100 million of our suns and lies fifty million light-years away from Earth.
Effelsberg 100 Metre Radio Telescope
Location: Bad Münstereifel, Germany | Diameter: 100 metres | Weight: 3,200 tonnes
Built between 1968 and 1971 in western Germany, the Effelsberg telescope was the largest fully steerable radio telescope for almost thirty years, until it was surpassed by the Green Bank Telescope. One of the biggest radio telescopes in the world, it takes just twelve minutes to make a full 360° rotation. It is used to observe pulsars, cold gas- and dust clusters, the sites of star formation, jets of matter emitted by black holes and the nuclei (centres) of distant galaxies.
Robert C. Byrd Green Bank Telescope
Location: West Virginia, USA | Diameter: 100 metres | First light: 2000
One of the world’s largest radio telescopes is the planet’s largest fully steerable radio telescope with 2,209 small motors that adjust its position using extremely precise movements. The off-axis GBT, nicknamed ‘Great Big Thing’, weighs 7,600 tonnes and is 148 metres tall. Discoveries have included a hydrogen gas superbubble lying 23,000 light-years away in the Ophiuchus constellation, and one of the most massive neutron stars in the Milky Way galaxy.
Five-Hundred-Metre Aperture Spherical Telescope
Location: Guizhou, China | Diameter: 500 metres | First light: 2016
Situated in a karst depression in southwest China, the Five-Hundred-Metre Aperture Spherical Telescope, or FAST, is the biggest radio telescope in the world. It is nicknamed Tianyin, which translates to ‘Sky’s or Heaven’s Eye’ and was built at a reported cost of $180 million. Its scientific goals are to detect neutral hydrogen to the edge of the universe which will help to construct images of the early universe; to detect new pulsars; and to participate in the search for extraterrestrial intelligence.