Header photo: An artist's impression of the UK-led CosmoCube spacecraft, which would orbit be tasked with listening out for an "ancient whisper" from the early universe on the far side of the Moon.
Nicolo Bernardini (SSTL Ltd) & Kaan Artuc (University of Cambridge)
Cosmologists from the University of Portsmouth are part of an international team which wants to unlock the secrets of the 'Cosmic Dawn', by sending a miniature spacecraft to listen out for an "ancient whisper" on the far side of the Moon.
The proposed mission will study the very early universe, right after the Big Bang, when it was still quite dark and empty before the first stars and galaxies appeared.
But to probe the cosmic 'Dark Ages', silence is essential. And Earth is a very 'noisy' place for radio signals, with interference from our atmosphere and all our electronics.
"It's like trying to hear that whisper while a loud concert is playing next door," said Dr Eloy de Lera Acedo, who is presenting the proposal today at the Royal Astronomical Society's National Astronomy Meeting 2025 in Durham .
"This makes it really hard to pick up those faint signals from billions of years ago. To detect a special radio signal that comes from hydrogen - the first, most basic and most abundant chemical element - in the early universe, we need it to be quiet.
"That's why we're proposing to send a small satellite to orbit the Moon and detect a signal which could hold clues about how everything began and how structures like galaxies eventually formed."
The UK-led CosmoCube mission would observe from the far side of the Moon, which acts like a giant shield, blocking out all the radio noise from Earth.
This would create a clear, quiet spot to "listen" for an "ancient whisper" and learn more about the universe's Dark Ages and Cosmic Dawn - periods that are currently largely unexplored.
"By doing this, CosmoCube aims to help us better understand how our universe transformed from a simple, dark state to the complex, light-filled cosmos we see today, with all its stars and galaxies," said de Lera Acedo, head of Cavendish Radio Astronomy and Cosmology at the University of Cambridge.
"Crucially, it will also help scientists investigate the mysterious dark matter and its role in shaping these cosmic structures."
CosmoCube will feature a precision-calibrated, low-power radio radiometer operating from a low-cost satellite platform in lunar orbit. It would operate at low frequencies (10-100 MHz), engineered to detect extremely faint signals amidst a sea of noise.
The mission could help shed light on the Hubble tension, a discrepancy between various measurements of the expansion rate of the Universe. It may also provide insights into the physics of the early Universe, and how normal and dark matter interact.
It may also provide insights into dark matter-baryon interactions (potential, non-gravitational interactions between dark matter particles and ordinary matter) and the physics of the early universe.
This so-called 'Dark Ages' period is one of the last unexplored frontiers in observational cosmology. The pre-stellar epoch offers a pristine view into the formation of structure, the properties of dark matter, and early cosmic evolution.
It's incredible how far these radio waves have travelled, now arriving with news of the universe's history.
Professor David Bacon, University of Portsmouth's Institute of Cosmology and Gravitation
"It's incredible how far these radio waves have travelled, now arriving with news of the universe's history," said fellow CosmoCube researcher Professor David Bacon , from the University of Portsmouth's Institute of Cosmology and Gravitation .
"The next step is to go to the quieter side of the Moon to hear that news."
Cosmo Cube is supported under the UK Space Agency's Science Bilateral Programme and is being developed by a UK-led international consortium with researchers based at the University of Portsmouth, University of Cambridge and STFC RAL Space.
Instrument development is well under way, with functioning lab prototypes and environmental testing taking place and key collaboration with industry partners, such as SSTL Ltd, developing the space platform and mission concept.
The team behind the project are planning for a 4-5 year roadmap to launch, with the goal of reaching lunar orbit before the end of the decade.
As a recognised international centre of research excellence, the University of Portsmouth's Institute of Cosmology and Gravitation (ICG) brings together more than 70 researchers - faculty, postdoctoral fellows and PhD students - tackling some of the Universe's most profound mysteries, from the earliest moments after the Big Bang to the large-scale structure of galaxies, dark energy and gravitational waves.
Its world-class impact was confirmed in REF 2021, where 100 per cent of ICG research was rated world-leading or internationally excellent.
The institute's contributions include roles in major international projects such as Euclid , LISA (Laser Interferometer Space Antenna) , the LIGO gravitational wave detectors , and the Dark Energy Spectroscopic Instrument (DESI).
