Scientists Develop Novel ‘Photophoresis’ Technology to Explore Earth’s Mysterious Mesosphere
Table of Contents
A groundbreaking new approach to atmospheric sensing, utilizing a phenomenon known as photophoresis, promises to unlock the secrets of the mesosphere – a largely unexplored layer of Earth’s atmosphere critical to climate and weather patterns.
For decades, the mesosphere, extending from roughly 50 to 85 kilometers above the planet’s surface, has remained a scientific enigma. Customary methods of atmospheric study – weather balloons and airplanes for lower altitudes, and satellites for higher ones – prove ineffective in this middle ground.It’s too low for stable satellite orbits, yet too sparse for conventional flight. This lack of data has earned it the nickname “ignorosphere,” as scientists have been forced to rely on assumptions to understand its complex role in global systems.
The Challenge of Studying the Mesosphere
The mesosphere exists at a unique intersection, influenced by both terrestrial weather systems rising from below and solar activity impacting from above. It reacts to events as diverse as hurricanes and solar storms, acting as a crucial interface between atmospheric layers. However, the inability to deploy stable monitoring equipment has severely hampered our understanding. “We haven’t been able to place any stable monitoring equipment in it,” a senior researcher explained, “due to the limitations of balloons and satellites.”
Photophoresis: A New path to Atmospheric Exploration
published on August 13th in Nature, a new study details a potential solution: harnessing photophoresis. This process leverages the fact that gas molecules colliding with the sun-facing (“warm”) side of an object impart more energy than those colliding with the shaded (“cool”) side. This creates a minuscule force, detectable only in low-pressure environments like the mesosphere.
Researchers at Harvard and the University of Chicago overcame the challenge of this weak force by developing incredibly small structures using advanced nanofabrication techniques. Thes centimeter-scale prototypes were tested in a vacuum chamber replicating mesospheric pressure, and successfully levitated using just 55% sunlight. This marks the first presentation of a functional photophoresis-powered flight prototype, largely due to the structures’ exceptionally light weight.
Did you no?-the mesosphere, between 50-85 kilometers above earth, is tough to study due to its altitude. It’s too high for most aircraft and too low for stable satellite orbits, leading to limited data and its nickname, the “ignorosphere.”
Beyond Earth: Implications for Planetary Science
The potential applications of this technology extend far beyond Earth’s atmosphere. Mars, with its thin, low-pressure atmosphere, is an obvious candidate for exploration using photophoresis-powered sensors. Other planets and moons with similar atmospheric conditions could also benefit from this innovative approach. “Anything that has an atmosphere that is spare enough to support a levitating spacecraft could be served by one of these fliers,” one analyst noted.
The Road Ahead: From Prototype to Payload
Despite this breakthrough,critically important engineering hurdles remain. The current prototypes lack the essential components for scientific data collection – sensors and wireless interaction equipment. A floating structure without the ability to transmit information is, understandably, of limited scientific value. The researchers acknowledge the need to refine nanofabrication techniques to integrate a functional payload into these devices.
Though, the team is optimistic. They have already established Rarefied Technologies, a startup company accepted into the Breakthrough Energy Fellows program last year.With this support and ongoing research, they anticipate deploying centimeter-sized sensors throughout the “ignorosphere” – and beyond – in the near future.
The progress of photophoresis-powered flight represents a paradigm shift in atmospheric exploration, offering a pathway to unravel the mysteries of our planet’s upper atmosphere and potentially revolutionize our understanding of other worlds.
(head elements, dateline, schema)
