British scientists and engineers are helping to open a new window on the Universe after a groundbreaking instrument, led by a team in Edinburgh, successfully made its first observations from one of the world’s most powerful telescopes.
A remarkable new piece of astronomical technology, developed by an international team led from Britain, has successfully peered into the heart of the Milky Way for the first time, marking the beginning of what scientists hope will be a new era of cosmic discovery.
The Multi-Object Optical and Near-infrared Spectrograph, known as MOONS, has achieved what astronomers call “first light” at the European Southern Observatory’s Very Large Telescope at the Paranal Observatory in Chile.
Behind the formidable piece of technology is a consortium led by the UK Astronomy Technology Centre in Edinburgh, part of Britain’s Science and Technology Facilities Council.
It is another reminder that, when it comes to science, engineering and innovation, Britain continues to punch well above its weight on the world stage.
More than a decade of work has gone into MOONS, bringing together scientists, engineers and technicians from the UK, Italy, France, Portugal, Switzerland and Chile, alongside the European Southern Observatory.
For its first observations, the instrument turned towards the densely populated heart of our own galaxy.
The centre of the Milky Way is notoriously difficult to study because enormous quantities of interstellar dust obscure our view. MOONS, however, is sensitive to near-infrared wavelengths, allowing it to penetrate that dust and examine stars in regions that are otherwise extremely difficult to observe.
And what makes the instrument particularly extraordinary is the sheer scale at which it can work.
MOONS effectively gives astronomers almost 1,000 eyes on the Universe at once.
Rather than taking conventional photographs, the spectrograph splits light arriving from stars and galaxies into detailed spectra. From these patterns, scientists can uncover an extraordinary amount of information, including an object’s chemical composition, temperature, movement and distance from Earth.
Most impressively, MOONS can do this for nearly 1,000 stars or galaxies simultaneously.
Combined with the enormous eight-metre aperture of the Very Large Telescope, this makes MOONS one of the most powerful spectroscopic facilities ever constructed.
Over its working life, scientists expect it to examine millions of stars and galaxies, helping them investigate some of the greatest questions in astronomy, including how our Milky Way was formed, how galaxies developed over billions of years and how the Universe itself has changed throughout cosmic history.
Dr Oscar Gonzalez, MOONS UK Principal Investigator and Head of Project Science and Strategy at the UK Astronomy Technology Centre, described first light as the moment when years of hard work were finally transformed into discovery.
“MOONS is the result of an extraordinary international effort,” he said.
“For years our scientists, engineers and technicians have worked together to overcome remarkable technological challenges and create an instrument of exceptional capability.
“For me, first light is a celebration of their expertise, dedication and perseverance. It marks the exact moment in which years of work are transformed into discovery.”
He added that MOONS would allow astronomers to make observations which had previously been beyond their reach.
The engineering required to make that possible is almost as astonishing as the science itself.
MOONS is now installed more than 2,600 metres above sea level in Chile’s Atacama Desert. Its optics and mechanisms are cooled to around 130 Kelvin, approximately minus 140C, while its detectors operate at roughly 40 Kelvin, or minus 230C.
Those extreme temperatures are necessary to achieve the stability and sensitivity required to detect extraordinarily faint light travelling from distant stars and galaxies.
The instrument uses an enormous cryostat, believed to be the largest ever constructed for a ground-based astronomical telescope.
Its robotic fibre positioning system is another extraordinary feat of precision engineering. It can position around 1,000 optical fibres onto targets in the sky with micrometre accuracy, allowing scientists to study enormous numbers of objects far more efficiently than previously possible.
Professor Michele Dougherty, Executive Chair of the Science and Technology Facilities Council and the UK Astronomer Royal, travelled to Chile to witness the milestone alongside the UK Astronomy Technology Centre team.
She hailed the achievement as evidence of Britain’s continuing strength in astronomical science and technology.
“Seeing MOONS achieve first light was tremendously exciting,” she said, describing it as a landmark moment both for those responsible for building the instrument and for astronomy more widely.
Professor Dougherty said MOONS demonstrated “the UK’s world-leading expertise in astronomical technology” and showed how investment in ambitious international projects could keep British scientists and engineers “at the forefront of discovery”.
Michele Cirasuolo, MOONS Principal Investigator and ESO Instrumentation Programme Manager, said the instrument would allow scientists to investigate the properties of millions of stars and galaxies spanning more than 13 billion years of cosmic history.
“It will take us to new frontiers in our understanding of how the Milky Way and galaxies have formed and evolved with time,” he said.
With first light successfully achieved, scientists and engineers will now continue commissioning and calibrating MOONS before full scientific operations begin.
It is expected eventually to become one of the cornerstone instruments of the Very Large Telescope, producing enormous quantities of scientific data and working alongside discoveries made by other major observatories and space missions.
For Britain, there is something particularly satisfying about the achievement.
From Isaac Newton’s work on gravity and optics, to William Herschel’s discovery of Uranus, through to Stephen Hawking’s work on the fundamental nature of the Universe, this country has an extraordinary scientific inheritance.
That tradition is very much alive.
In laboratories and engineering facilities in Edinburgh, British expertise has helped create an instrument capable of looking through the dust of our own galaxy and studying light that has travelled across almost the entire history of the Universe.
MOONS may be sitting on a mountain thousands of miles away in Chile, and its creation has rightly been an international endeavour, but British scientists and engineers have been at the heart of making it happen.
The discoveries are only just beginning.
