Specialists in the field of space exploration are currently conducting research on the roofs of England’s cathedrals to collect samples of interstellar dust, which they refer to as “cosmic cleaners”.
On the roof of Canterbury Cathedral, two planetary scientists are searching for cosmic dust. While the red brick parapet hides the streets, buildings and trees far below, only wispy clouds block the deep blue sky that extends into outer space.
The roaring of a vacuum cleaner breaks the silence and researcher Dr Penny Wozniakiewicz, dressed in hazmat suit with a bulky vacuum backpack, carefully traces a gutter with the tube of the suction machine.
“Currently, we are on the hunt for minute microscopic spheres,” describes Dr. Matthias van Ginneken, a colleague of hers from the University of Kent, who is also donned in protective gear. “Our current task involves collecting a vast amount of dust particles, with the hope of finding a small portion that originated from outer space.”
A majority of the space debris that strikes Earth annually is incinerated in the atmosphere – certain estimates indicate that 15,000 tons manage to reach and interact with Earth’s atmosphere (equivalent to approximately 75 blue whales). However, an estimation based on Antarctica suggests that around 5,200 tons of micrometeorites actually reach and land on Earth. These small particles, believed to originate from comets and asteroids, typically range from 50 microns to two millimeters in size.
Van Ginneken explains that one must possess a certain degree of sleuthing skills. The intense heating during atmospheric entry alters numerous minerals, making it necessary to deduce the nature of the original particle with the limited information available.
Scientists are using micrometeorites to gain insight into the chemical composition of asteroids and meteorites. Through studying isotopic diversity, they can gather information about the origin of the cosmic debris and how it was affected during its entry into Earth’s atmosphere.
In the earlier stages, there was a greater abundance of cosmic dust due to the increased number of collisions within our solar system during Earth’s infancy. This dust, which is now preserved in rocks, provides clues about the occurrences in our planetary surroundings throughout Earth’s timeline, as well as any alterations that have occurred.
Van Ginneken and Wozniakiewicz are attempting to comprehend the variations in micrometeorite flux and other scientific inquiries.
According to Wozniakiewicz, by determining the number of dust particles reaching the surface, one can approximate the amount of material that is entering Earth over a period of time. This could potentially shed light on the role of space dust in Earth’s chemistry.
These cosmic materials have two paths – some remain on the surface where they can interact with surface chemistry, while others disintegrate in the atmosphere and participate in atmospheric chemistry.
Small space debris, known as micrometeorites, can introduce uncommon elements to both land and sea surfaces, and even the atmosphere. These elements can impact the behavior of these natural systems.
Wozniakiewicz and Van Ginneken are looking for a specific type of extraterrestrial dust: cosmic spherols. These tiny spheres are relatively easy to identify compared with other dust, because of their distinctive shape, but it takes a microscope to be certain that a cosmic spherol did not come from Earth. This makes them useful in estimating how much cosmic dust fell in a particular place over a given time period.
Previously, it was believed to be unachievable to gather cosmic particles in cities – it was only found in unaltered locations like the Antarctic or in fossilized sediment. However, in 2009, Jon Larsen, a jazz musician from Norway who had shifted his focus to collecting cosmic dust, started sifting through large amounts of urban dust in search of cosmic particles. In 2017, Larsen and his colleagues, including Van Ginneken, published an influential report in the journal Geology, demonstrating that anyone with a microscope and determination could uncover cosmic globes.
Collecting micrometeorites for scientific research is challenging due to the risk of contamination. Despite continuously falling on Earth’s surface, these particles are susceptible to outside elements that may affect their usefulness in experiments. This explains why Van Ginneken and Wozniakiewicz wear protective gear resembling white-clad aliens while searching for micrometeorites. The gear also serves to guard against potential bird flu outbreaks, as droppings and bird bones can carry the virus.
Van Ginneken credits Larsen with initiating the trend of studying urban micrometeorites. As a result, this has become a popular hobby for many individuals. Penny and I aim to elevate this hobby into a scientific pursuit.
Reworded: Canterbury’s cathedral roofs, like the one at Canterbury Cathedral, are perfect for searching for cosmic dust due to their large size, inaccessibility, and minimal disturbance. Our entrance into the roof begins at a typically locked wooden door located at the back of the Trinity Chapel, followed by a climb up hundreds of narrow stairs, and finally passing through another specially unlocked door to reach the cathedral’s roof. This particular rooftop was the last one visited by Van Ginneken and Wozniakiewicz, who had already climbed to several other roofs on the cathedral earlier that day. They have also been able to gather dust from the roofs of Rochester Cathedral and have plans to do the same at Salisbury and Winchester.
Ginneken is interested in studying a variety of roofs in order to identify potential biases in urban micrometeorite collections, including the impact of rainwater. He notes the convenience of studying roofs, as they are easily accessible. While Antarctica has been a popular location for micrometeorite research, Ginneken acknowledges the high cost and limitations on sample collection. Additionally, this research is limited to a specific climate and latitude. Examining roofs offers a wider range of environments to study the interaction behavior of these small dust particles.
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The prevalence of small meteorites within urban areas provides an opportunity for non-specialists to contribute to planetary science, even without access to materials from major space missions. Furthermore, there is a growing curiosity about the treasures of outer space, as demonstrated by NASA’s OSIRIS-REx mission which gathered material from the 4.5 billion year old asteroid Bennu and returned it to Earth last year.
Wozniakiewicz praises the effectiveness of singular missions, which focus on one specific object, providing valuable information about that object. In contrast, micrometeorites offer insight into a multitude of objects and can paint a bigger picture of the overall asteroid population, showcasing the various processes and bodies in space. By comparing samples from these missions and meteorites, we can gain a better understanding of the world beyond our own.
According to Dr Martin Suttle, a planetary science lecturer at The Open University, cosmic dust may contain valuable information about the history of our planet in the far past. A recent paper by Suttle and his colleagues in Nature Astronomy suggests that this dust may have also played a role in creating conditions suitable for the development of life on early Earth, potentially leading to its spontaneous emergence.
According to the speaker, Earth used to receive a significantly larger amount of dust, possibly 1,000 times more, compared to the present. This dust contained various materials that were essential for early prebiotic chemical processes, such as iron metal that was not naturally found on the Earth’s surface.
Collecting the particles from outer space is just the first step in the research process, and perhaps the simpler one – despite the challenging climb up the cathedral stairs. The bags of particles will undergo sterilization to ensure safety during handling, and then scientists will individually inspect each one under a sterile microscope.
Van Ginneken says they will spend countless hours extracting spheres in the hopes of finding a cosmic spherol.
Source: theguardian.com
