China to launch moon-orbiting telescope to explore the universe's Dark Ages by 2026

This proposed concept is called "Discovering Sky at the Longest Wavelength," or Hongmeng Project, and might orbit the moon by 2026.

The design of the orbiting telescope 

According to Space.com, China's plan is to launch a small constellation of satellites to orbit around the moon. This constellation will function as a radio telescope, thereby, enabling astronomers to study the cosmic world in a whole "new window." 

In terms of design, it will consist of one main "mother" satellite followed by eight mini "daughter" ones. 

The primary satellite(mother) would be in charge of processing data and relaying it back to Earth, while the daughters would work to capture mysterious radio signals from distant objects in the cosmos. 

The CNSA astronomers believe that a network of satellites orbiting the moon would be more technically possible than erecting a telescope directly on the lunar surface. The latter would require large infrastructure from Earth, after which astronomers would have to build it on the Moon, which may be a difficult, time-consuming, and expensive process. 

"There are a number of advantages in doing this in orbit instead of on the surface because it's engineeringly much simpler," said Xuelei Chen, an astronomer at the CNSA during the conference. "There is no need for landing and a deployment, and also because the lunar orbital period is two hours, we can use solar power, which is much simpler than doing it on the lunar surface, which, if you want to observe during the lunar night, then you have to provide the energy for almost 14 days," Chen added. 

Studying the universe in the electromagnetic spectrum 

The vision of this constellation-based telescope is one of its most significant advantages.

It would enable astronomers to monitor cosmic signals in a specific region of the electromagnetic spectrum. Due to the Earth's atmosphere, this form of observation is typically impossible from the planet. 

"If you are looking into the low-frequency part of the electromagnetic spectrum, you'll find that, due to strong absorption [by Earth's atmosphere], we know very little about [the region] below 30 megahertz. It's almost a blank part of the electromagnetic spectrum. So we want to open this last electromagnetic window of the universe," explained Chen. 

But why this particular spectrum? Detecting this electromagnetic spectrum may help us comprehend one of the most mysterious periods of the early universe: the Dark Ages. 

This occurred during the first few hundred million years following the Big Bang when the universe was shrouded in utter darkness

Furthermore, the telescope will acquire data when on the far side of the moon. The moon’s far side is noted to be the most “radio-quiet place,” and is devoid of man-made radio noise. When the mother spacecraft crossed the moon's planet-facing face, it would send the data to Earth.

If everything goes as planned, this telescope will provide a new window to capture the mysterious signals emanating from distant cosmic objects and reveal secrets of the early universe.