Tiny satellite to use the dark side of the Moon to eavesdrop on whispers from the early universe
University of Portsmouth scientists are supporting an international mission to unlock the secrets of the Cosmic Dawn
A tiny UK-developed satellite, roughly the size of a small carry-on suitcase, could help answer one of the biggest questions in cosmology: what happened in the roughly 150 million years of cosmic dark ages, before the universe’s first stars appeared?
An international team, led by the University of Cambridge and including scientists from the University of Portsmouth, will use the dark side of the Moon as a ‘shield’ so that the satellite – called CosmoCube – can block out all the noise from Earth and listen for a faint whisper from the very early universe.
This whisper, known as the 21-centimetre line, is a signal emitted by hydrogen atoms in the period in between the afterglow of the Big Bang and Cosmic Dawn, when nuclear fusion lit up the first stars. No one has directly observed this era before.
Detecting this signal from more than 13.5 billion years ago is extremely difficult with Earth-based telescopes, since the Earth’s ionosphere blocks the right frequencies, and interference from FM radio, satellites and telecommunications drowns it out.
However, the Moon provides a natural shield. As CosmoCube orbits the far side of the Moon, it will be shielded from all the noise of Earth for roughly 40 minutes of each two-hour orbit.
Over an expected two-year mission, it will build up 1000 hours of data on one of the last unexplored periods of the universe, helping experts to understand how the universe transitioned from dark and nearly empty to the complexity we see today.
The mission has received funding for mission design from the UK Space Agency, and the researchers hope CosmoCube can be launched within the next five years.
Details are published in the journal Nature Astronomy.
CosmoCube researcher Professor David Bacon, Director of the University of Portsmouth’s Institute of Cosmology and Gravitation which is participating in the mission, added: “How extraordinary it will be to observe the era before the stars started to shine - and to have the Moon as our ally in this effort!”
As a recognised international centre of research excellence, 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.