Why-We-Should-Really-Put-a-Particle-Accelerator-on-the-Moon

In the March 1988 issue of Popular Mechanics, sci-fi author Isaac Asimov proposed building a particle accelerator on the moon.A physicist recently revisited the idea in a paper published to the preprint website arXiv.org.The moon, it turns out, might actually be a perfect place to put one.

In the March 1988 issue of Popular Mechanics, the legendary science fiction author Isaac Asimov wrote an article describing his vision for humanity’s return to the moon.READ ITIsaac Asimov: ‘How We’ll Live on the Moon’

In the article, Asimov envisioned the year 2028. Humans—or Lunarians, as he called them—are thriving on the moon. They’ve erected a massive radio telescope on the moon’s far side and have built research stations, factories, and celestial observatories, all powered by nuclear and solar energy.

The moon, Asimov mused, is the ideal scientific laboratory, one that could help us unravel the mysteries of particle physics. “Turning to the heavens, special detectors would analyze rays from astrophysical sources, and moon-based particle accelerators would give new insight into the nature of matter,” he wrote.

Particle accelerators use electric fields to propel a beam of charged particles. Physicists use electromagnets to steer the particles along either a linear or a circular path.

Now, thirty-two years after Asimov first floated the idea in the pages of our magazine, physicist Nikolai Zaitsev explains why the moon is indeed the perfect environment for a particle accelerator.

“This natural satellite is surrounded with deep vacuum, is at low cryogenic temperatures and is always facing the Earth with one side,” Zaitsev writes in a paper published to the preprint website arXiv.org.

Let’s break down some of these reasons:

  • Vacuum: On Earth, physicists have to create a vacuum through which the beam will travel free of gas molecules and microscopic grains of dust. The moon has no atmosphere and thus exists in a vacuum. The conditions that physicists work so hard to create here on Earth are already built into the lunar environment.
  • Temperature: In order to cool the powerful magnets that steer the particles, accelerators need to operate in frigid temperatures. The high-powered magnets that steer the particles must be cryogenically cooled. Some of the coldest temperatures in the solar system—try minus 413 degrees Fahrenheit—have been observed in the shadows of lunar craters near the moon’s poles.
  • Tidal locking: Additionally, the one side of the moon is always facing Earth. This would be crucial for Earth-based detectors, which would be positioned to intercept streams of neutrinos.
  • Proximity: Well, it’s the closest world to us. If we’re ever going to stick a particle accelerator on another world, it ought to be the moon.

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“Neutrinos and gravity waves, together with other exotic cosmic manifestations, might be detected more easily and studied from the moon than from the Earth,” Asimov wrote in 1988, before the abundant subatomic particle had been discovered. In lockstep with Asimov, Zaitsev suggests that developing an accelerator could generate neutrinos, which are abundant in the universe, but are notoriously difficult to detect because of their minuscule mass and lack of electrical charge.

Zaitsev also proposes that the accelerator could be direct cosmic rays—an enemy to fragile astronauts and Earth’s electrical systems—toward Earth’s atmosphere for ground-based instruments to study.

“By shooting them into Earth one can better study the physics of atmospheric showers and calibrate respective models which are key part of cosmic rays physics,” Zaitsev writes. (If that isn’t the plot of a James Bond movie, we don’t know what is.)

The obvious drawback of these projects is that they’re incredibly expensive. We’re just now making our way back to the moon after a 50-year hiatus, and particle accelerator projects are habitually delayed.RELATED STORIESNeutrinos Could Explain the UniverseThe Tiniest Particle Accelerator You’ll Ever SeeCan a Particle Accelerator Power a Spacecraft?

Another concern, Zaitsev points out, will be moonquakes. Particle accelerators are incredibly sensitive to movement. The surface of the moon is susceptible to shakes, rattles, and rolls generated by meteorite impacts, thermal cycles, and the tidal forces between the moon and Earth. It’s a tough environment for precise instrumentation.

And then there’s the radiation. Lunar workers would already by susceptible to harmful cosmic radiation raining down on them, but they would also be exposed to the secondary radiation generated during experiments.

A diagram of the BEAR project payload system, part of the first particle accelerator launched into space.LANL

Asimov wasn’t alone in suggesting we develop an extraterrestrial particle accelerator. In fact, just a year later, the Los Alamos National Laboratory launched the BEAM experiment Aboard Rocket (BEAR) project. It became the first successful test of low-energy linear accelerator technology in orbit.

Scientists have dreamed of outfitting our closest neighbor with fantastical technology for a long time. NASA is currently funding research into another project Asimov mentioned: that lunar radio telescope.

Originally Publish at: https://www.popularmechanics.com/