NASA, scientists devise ways to ensure 'microbe-free' return of Mars sample

NASA's Perseverance rover, which has been treading Mars since February 2021, is collecting samples of rocks and soil in order to expand our understanding of the red planet. The samples collected by Perseverance will be brought to Earth no earlier than 2031 under the Mars Sample Return campaign managed by both NASA and the European Space Agency (ESA). Since the materials fetched by the rover will be an alien commodity for Earth, scientists from Florida Atlantic University have collaborated with NASA to devise a method for sterilising the samples and making them microbe-free.

Before NASA launched Perseverance to Mars in July 2020, they had sterilised the rover in order to prevent it from carrying micro-organisms from Earth and contaminating the red planet. To ensure that the sample returns microbe-free, the agencies will launch Perseverance's sample container to Mars' orbit, where a spacecraft would collect it and package it into a sealed container. The sample would be sterilised inside this container which would be sealed into another vessel. 

"Our plan is to ensure that when the samples return to Earth, potentially hazardous material from the Mars rover is either fully contained or sterilized. In addition, it's imperative for the samples obtained by the rover to be contained within an ultra-clean environment when it returns to Earth", Gregg Fields, from the Florida Atlantic University said as per the institute's report. "That way, scientists will know that any potential discovery of ancient life did in fact originate on the red planet", Fields added.

Apart from sterilising the microorganisms in Martian dust and rocks, scientists are also working to inactivate or encapsulate any potentially hazardous bioactive particles such as proteins that might arrive on Earth. The experts are reportedly planning to do that by sealing and heating the samples tubes in multilayered vessels by exposing them to temperatures up to 350-450 degrees celsius. Although scientists are preparing on all fronts, Fields said, "I don't think that there are any dangerous microorganisms and proteins on Mars, but we still have to prepare and protect against it". 

Perseverance rover and its journey so far

The rover has spent 314 days as of January 7, after it landed on the red planet on February 18, 2021. Perseverance touched down Mars' Jezero crater and is exploring the region which once housed giant lake billions of years ago. The car-sized rover is equipped with seven science instruments and 23 cameras and has been assigned the job to collect as many as 30 samples before they are shipped to Earth. 

(Image: NASA)