Observatory on the far side of the moon will seek ‘Dark Ages’ signal

The LuSEE-Night observatory will also demonstrate lunar night survival technology that withstands harsh space conditions.

Chris Young
Observatory on the far side of the moon will seek ‘Dark Ages’ signal
An image of the far side of the moon.

NASA / Goddard / Arizona State University 

In a few years’ time, scientists aim to place a small radio telescope on the far side of the moon to help them peer into the universe’s ancient past.

The space observatory, called the Lunar Surface Electromagnetics Experiment-Night (LuSEE-Night), is a pathfinder, meaning it will be used to detect signals and locations that more powerful telescopes can then investigate in greater detail.

It is currently slated to launch to the moon aboard a private robotic lander in late 2025. Once there, it will use the radio silence of the far side of the moon to shed new light on the “Dark Ages” of the universe.

Searching for the Dark Ages Signal

The Dark Ages of the universe refers to a period of the early universe, between about 400,000 and 400 million years after the Big Bang, before stars and galaxies had formed.

Remnants from that time still exist in the form of very faint radio signals sometimes referred to as the Dark Ages Signal. LuSEE-Night will feature onboard antennas, radio receivers, and a spectrometer to measure these faint radio waves from the universe’s distant past.

“So far, we can only make predictions about earlier stages of the universe using a benchmark called the cosmic microwave background. The Dark Ages Signal would provide a new benchmark,” Brookhaven physicist Anže Slosar explained in a press statement. “And if predictions based on each benchmark don’t match, that means we’ve discovered new physics.”

Lunar night survival technology

The far side of the moon is an ideal location to look for faint signals from the ancient universe because it provides silence from the barrage of radio signals emitted from Earth. However, having an observatory survive on the far side of the moon poses its own challenges, as the moon’s far side has a day/night cycle, each lasting about 14 Earth days.

That means LuSEE-Night will have to be designed to withstand extended periods of harsh cold as well as intense heat, with a temperature range of around 250 to minus 280 degrees Fahrenheit (121 and minus 173 degrees Celsius).

The observatory, which will also serve as a robust demonstrator for long-lasting moon technology, is currently being developed by the U.S. Department of Energy’s Brookhaven and Lawrence Berkeley National Laboratories, the Space Science Laboratory at the University of California, Berkeley, and NASA’s Science Mission Directorate.

“In addition to the significant potential science return, demonstration of the LuSEE-Night lunar night survival technology is critical to performing long-term, high-priority science investigations from the lunar surface,” explained Joel Kearns, deputy associate administrator for exploration in NASA’s Science Mission Directorate.