Researchers aiming to uncover the secrets of the early universe plan to use a suitcase-sized satellite called CosmoCube in lunar orbit to detect weak radio signals from neutral hydrogen atoms, bypassing Earth-based interference. According to Prof Eloy de Lera Acedo of the University of Cambridge’s Cavendish Laboratory, the mission targets the 21cm line, a frequency whose wavelength has been stretched over time, acting as a cosmic thermometer for the universe’s gas temperatures.
Targeting the Universe’s Dark Ages From Lunar Orbit
The CosmoCube mission aims to observe events starting from the cosmic dark ages roughly 380,000 years after the big bang, stretching through the cosmic dawn and the epoch of reionization about one billion years later. According to de Lera Acedo, the physical temperature of gas during these periods is directly affected by surrounding events, and the amplitude and shape of the 21cm signal are expected to reveal clues about dark matter.
The two-year mission is estimated to cost just under £50m, with a targeted launch date about five years from now, according to de Lera Acedo. The project has already secured more than £2m in funding from the UK Space Agency. Phil Bull, a professor of cosmology at the Jodrell Bank Centre for Astrophysics who is not involved in the project, stated that the measurements will help clarify the processes behind the formation of the first stars and galaxies.
Overcoming Earth-Based Radio Interference
Detecting the 21cm line from Earth remains notoriously difficult due to weak signals and heavy human-made interference, ranging from FM radios to airplane communications. Writing in the journal Nature Astronomy, the research team noted that disturbances created by Earth’s ionosphere further complicate ground-based observations.
While the Edges radio telescope project in Australia previously reported finding the 21cm signal, those results faced outside questions. By positioning CosmoCube near the far side of the moon, researchers expect to shield the instruments from terrestrial noise. However, Bull warned that the mission faces a race against time as other planned lunar missions risk bringing similar human-generated radio noise to the moon’s far side.
Did You Know?
The far side of the moon always faces away from Earth because the moon takes the same amount of time to complete an orbit and rotate around its axis—about 27 days, according to NASA data.
Frequently Asked Questions
What is the 21cm line?
The 21cm line is a radio frequency signal emitted by neutral hydrogen atoms in the early universe, which scientists track to measure gas temperatures and study cosmic origins.
Why use the far side of the moon for astronomy?
The far side of the moon provides a natural shield against human-made radio frequency interference from Earth, such as FM radio waves and aircraft communications, which disrupt sensitive space instruments.
How much will the CosmoCube mission cost?
The total cost of the CosmoCube mission is estimated to be just under £50m, with over £2m already granted by the UK Space Agency.
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