New device aims to protect the Earth from Martian microbes

The possibility of life on other planets is one of the biggest mysteries in science. But what would happen if we actually found it? Our scientists are preparing for this possibility by helping to develop a new system that can analyze samples for signs of extraterrestrial life while keeping the planet safe.

Across the UK, plans are in progress to save Earth from alien invaders.

It’s not little green men with flying saucers and laser guns that scientists are worried about, instead our foes will be much smaller. If life does exist on planets such as Mars, it’s likely that it’ll be in the form of microbes, and we don’t know how these organisms might affect us.

As space agencies consider bringing Mars samples back to Earth for the first time, researchers are working to develop ways that allow them to analyze the samples for signs of Martian life while protecting this planet. One such project is the double-walled isolator (DWI), an ultra-clean miniature laboratory that would allow scientists to safely store and analyze materials from space.

This device has been developed over the past few years by our scientists alongside colleagues at the Francis Crick Institute and the University of Leicester. The DWI has had interest from the European Space Agency and NASA, whose officials recently visited the three institutions to find out more. The study is published in the journal Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

Professor Caroline Smith, one of our experts who has been involved in its development, says that the “unique” technology could one day be used for far more than space science.

“The DWI is the product of years of research by researchers and engineers across the UK,” explains Caroline. “It’s been designed for analyzing samples returned from other worlds, but there are many other applications it could have.”

“For example, it could be used by pharmaceutical companies to develop new medicines that need to be made in very specific conditions. By working together with different industries, we hope to advance this technology for the benefit of the planet.”

From Mars to Earth

Currently, the only samples of Mars that have made their way to Earth are Martian meteorites. These are lumps of the red planet which were blasted into space during asteroid strikes millions of years ago, and later fell to Earth after being caught in our planet’s gravity.

While Martian meteorites can teach us about the geology and history of Mars, there’s a lot of information they can’t reveal. The reactions that happen once a meteorite enters Earth’s atmosphere transform its chemistry, meaning crucial details are lost forever.

Instead, scientists have long been hoping for a Mars Sample Return mission, or MSR. This would see samples collected on Mars and sealed so that they would still be pristine by the time they reached Earth.

Decades after the first MSR missions were discussed, however, no Mars rocks have been brought to Earth. NASA’s Perseverance rover, which landed on the red planet in 2021, has been filling sample tubes to be brought back to Earth, but the project to do so was recently put on hold.

Other countries are continuing to push forward, with Japan hoping to return samples from Mars’ moon Phobos by 2031. China, meanwhile, is aiming to have completed its own MSR mission to the Martian surface in the same year and could be the first country to bring science rich samples back to Earth.

If samples are brought back from Mars, ensuring the safety of Earth’s biosphere is important. Any Martian microbes that might live in the samples would have evolved in an entirely different way to life on Earth, making it unlikely we would have any immunity to any diseases they could cause.

“The principles of planetary protection were first discussed in the 1950s, but they’re just as important today,” Caroline adds.

“There’s a good chance that Mars was habitable in the past, and it might still have life today. So, when samples are brought back to Earth, we have to assume that they are hazardous until we can prove otherwise.”

How are extraterrestrial samples studied?

Currently, samples of meteorites, asteroids and the moon are studied using glove boxes. These devices allow scientists to reach into a sterile box and study a sample while keeping it separate from the outside world.

“When we curate meteorites and similar materials, we know that they’re not harmful to us unless we drop them on our foot!” says Caroline. “Instead, the main risk is that they’re contaminated by Earth’s atmosphere and environment.”

“To combat this, the inside of the glove box has a higher pressure than the room outside, meaning any contaminants in the box are blown out. However, with a hazardous sample, this could release dangerous materials into the lab. The DWI is the solution.”

The device consists of multiple layers. It starts with an inner section kept at a lower pressure than the rest of the lab. The difference in pressure means that even if the inner layer is breached, gases would flow into the box and stop potentially hazardous material escaping.

The outer layer, meanwhile, is kept at higher pressure to prevent contaminants getting in. The gap between the inner and outer layers is then separated by an inert gas to provide an additional layer of protection.

Once a sample is loaded into the DWI, it can then be analyzed using a range of built in equipment including a microscope and Raman spectrometer. The handling of the sample itself is carried out by a robotic arm inside the inner box, which can be controlled remotely.

A prototype DWI built at Space Park Leicester has already demonstrated the ability to unpack, image and weigh a test sample before returning it to its original container. John Holt, a Space Park Leicester scientist who led its development, says that future versions might one day work on samples from upcoming moon missions such as Artemis.

“While the DWI’s full containment capability isn’t required for lunar materials, its ability to carry out automated handling and scientific characterization within an ultra-clean environment offers a significant advantage,” John explains.

“This has the potential to materially enhance the pace and scale of scientific return from such missions in the future.”

This story is republished courtesy of Natural History Museum. Read the original story here