To an Asteroid and Back

How St Andrews students viewed a historical moment in space research.

On 24 September, students of GeolSoc and AstroSoc escaped the rain for a while and gathered in the observatory’s Napier building. Their reason for being there: to watch the OSIRIS-REx spacecraft touch down in Utah, seven years after it had first left Earth. These lucky St Andrews students were treated to the NASA live stream complete with graphics, live footage, and even a guest appearance from the UK’s very own rockstar and astrophysicist Brian May. The view on the projector showing a room of NASA scientists jumping up from their seats cheering only confirmed it: these students were witnessing history.

The OSIRIS-REx spacecraft had been on a journey to the asteroid Bennu on the USA’s first asteroid sample return mission. Asteroid sample return is an incredibly important step in scientific research. Usually when we find asteroids they are discovered on Earth and must be retrieved as quickly as possible to avoid contaminants. However, the asteroid having already passed through the Earth’s atmosphere poses problems as it may have been contaminated or changed by that process. That’s why this mission is incredibly significant: it is a chance for scientists to study its composition in a clean room, having been unaffected by the Earth. Although the Japanese have done this twice before, this current asteroid sample return mission has managed to bring back much more material than previously, allowing for more material to be studied.

So why do scientists want to study the composition of asteroids? Jodie Sutherland, GeolSoc president and AstroSoc secretary, excitedly explains that asteroids are studied to “try and determine how the solar system formed”. She goes on to explain that this particular asteroid may also contain information pertaining to how life formed.

Jodie had the right idea: analysis of the Bennu samples reveals that water has been found inside its clay minerals. This could help confirm a theory that water originally made its way to Earth and allowed for life to start via asteroids. Bennu also appears to have high concentrations of carbon, an element that is the key building block for life. Sulphur was also found in the samples. Sulphur is an important constituent of amino acids, which form proteins in cells, so its discovery inside an asteroid furthers the likelihood of asteroids being the source of life on Earth. NASA also hinted, during a recent press conference, that samples would be stored away for future scientists with better technology to study.

Though this mission was successful, it was not without its challenges. The NASA livestream presenters explained that once barreling through Earth’s atmosphere, OSIRIS-REx had to deploy a parachute and land safely at the Utah Test and Training Range. The parachute deployed a bit earlier than expected, bringing the capsule slightly off course, but luckily NASA and the Air Force were still able to locate the capsule using tracking cameras. The process of retrieving the capsule was substantially more difficult as they had to safely navigate a field where weapons had been tested and live ammunition may still be present.

Found successfully, the capsule was taken to a clean room and then transported to NASA’s Houston Space Centre for analysis. Whilst Houston is keeping a significant portion of the asteroid, samples are set to be distributed to research teams globally, including the UK’s Natural History Museum. The samples may even touch the St Andrews community as Jodie Sutherland prepares for an internship with the asteroid team at the Museum. Jodie profoundly commented at the end of our interview: "If we can find something that tells us just a bit about how life could have formed it will be groundbreaking, maybe life-changing, definitely for the scientists involved.”

Image from WikiCommons