The Hang Son Doong cave in Vietnam, located in Quang Binh Province within Phong Nha-Ke Bang National Park currently holds the title as the largest known cave in the world. With dimensions exceeding three miles (5 km) in length and 660 feet (200 m) in height, this natural wonder could house 15 Great Pyramids of Giza within its vast chambers. Its enormous passages are so spacious that a Boeing 747 could hypothetically fly through parts of the cave. The unique “skylights” in the cave’s limestone structure allow sunlight to flood in, nourishing two jungles nestled within the cave, and creating an ecosystem unlike any other on Earth.

A Discovery Decades in the Making

As per a recent report by LiveScience, Hang Son Doong, meaning “Mountain River,” was first discovered by Ho Khanh, a local resident, in 1990. Khanh stumbled upon the cave while hunting, noting the rush of wind and sound of water echoing from inside. However, surrounded by dense foliage, he was unable to relocate it until 2009. That year, Khanh successfully led a team from the British Cave Research Association, including cave expert Howard Limbert, to its entrance. Limbert, technical director at Oxalis Adventure, which now organises tours of Son Doong, described the discovery as monumental, with the team quickly recognising its scale and significance.

A Cave of Record-Breaking Dimensions

Upon detailed exploration, researchers determined that Hang Son Doong has a total volume of around 1.35 billion cubic feet (38.5 million cubic metres). This makes it the largest natural cave ever measured. In 2019, divers found an underwater tunnel connecting Son Doong to Hang Thung, adding another 57 million cubic feet (1.6 million cubic metres) to its volume. Limbert compared the discovery to “finding an additional peak on Mount Everest,” underscoring the cave’s unmatched scale in the subterranean world.

A Natural Masterpiece and Ecosystem

Beyond its size, Son Doong features remarkable geological formations. It houses one of the world’s tallest stalagmites, standing 260 feet (80 m) high, and includes the Great Wall of Vietnam, a calcite barrier that challenged explorers on their initial visits. The cave’s fossil passages offer a glimpse into the area’s ancient marine history, with fossils from sea creatures that once inhabited the region. Inside the Passchendaele Passage, named after a World War I battlefield, explorers encounter muddy terrain that mirrors the historic battlefield’s conditions.

In the heart of the cave, the collapsed ceiling forms skylights that allow light to reach its depths, nurturing thriving jungles and completing the surreal landscape of Son Doong.

In 2015, U.S. Navy pilots conducting training flights along the East Coast reported encounters with unusual, high-speed objects moving over the water. Descriptions from the pilots reveal that these oval-shaped objects appeared to rotate as they moved, covering vast distances at incredible speeds. Multiple pilots confirmed sighting these objects, which they noted were different from any known aircraft; they had no visible engines, exhaust, or defining propulsion systems.

According to Lt. Ryan Graves, a seasoned F/A-18 Super Hornet pilot with over a decade of experience, these objects were not a one-time sighting but were observed repeatedly over a period of months. The pilots’ observations, recorded on video, showed the objects not only hovering above the ocean’s surface but also appearing at altitudes of up to 30,000 feet, travelling at speeds beyond the capabilities of conventional military aircraft.

A Secret Unveiled to the Public

The public was made aware of these sightings in 2019 which was four years after they took place, when The New York Times published an article including the footage captured by the Navy. This article marked the beginning of a shift in how the U.S. government and the military approached the topic of unidentified aerial phenomena (UAP), as they are now officially termed. Shortly after, in April 2020, the U.S. Navy officially verified the authenticity of these videos, sparking renewed public and scientific interest in the nature and origin of these mysterious sightings.

Roswell and UFO Fever: A Lingering Curiosity

Public curiosity around UFOs is not new. In 1947, the Roswell Incident—where debris from an unidentified object was discovered on a ranch near Roswell, New Mexico—captured the nation’s imagination. Initial reports suggested it was a “flying saucer,” though the Army quickly retracted this, claiming the debris was from a weather balloon. This incident began a national obsession with UFOs, and the lore around Roswell has only grown over the decades. The Roswell Incident, combined with further sightings and theories around “Area 51,” left a lasting cultural impact on the public’s perception of UFOs and government secrecy.

Government Engagement and Investigation

As UAP sightings continued, the U.S. government initiated a more transparent approach to investigations. In 2021, a report was released acknowledging the existence of several unexplained UAP incidents since 2004, while maintaining that there was no evidence to suggest these sightings were of extraterrestrial origin. However, the U.S. government did highlight the need for investigation, given the potential implications for national security.

In response, the Pentagon established the All-domain Anomaly Resolution Office (AARO) in July 2022, tasked with coordinating and leading efforts to gather and analyse information on UAP. While there is no conclusive evidence linking UAP to extraterrestrial life, the objective remains to uncover the origins of these sightings, including the possibility of advanced foreign technology.

Science Takes a Stand

The rising interest in UAP has encouraged scientists to step forward in challenging long-standing stigma. NASA formed a scientific panel in 2022 dedicated to exploring UAP with an evidence-based approach. Harvard astrophysicist Avi Loeb has also made waves in the scientific community by establishing the Galileo Project, which applies observational and analytical technology to gather objective data on UAP.

Australian researchers have discovered a new method to detect plastic waste on beaches, using satellite imagery that allows them to identify plastic debris from over 600 km above the Earth’s surface. This breakthrough comes from a team at RMIT University, led by Dr. Jenna Guffogg, who conducted field tests on a secluded beach in Victoria. By tracking variations in how light reflects off different materials, such as sand, water and plastic, this tool could revolutionise how plastic waste on shorelines is detected and managed.

A New Approach to Plastic Pollution Monitoring

As per a report by Earth, the traditional satellite technology has long been effective in identifying massive floating trash patches in oceans, but it struggles to spot smaller, scattered debris along coastlines where waste blends with natural elements like sand. The new tool, known as the Beached Plastic Debris Index (BPDI), overcomes this limitation by using a specific mathematical formula to isolate light reflections specific to plastic. This technique provides images that can help pinpoint beach areas with high concentrations of plastic waste, enabling targeted clean-up efforts.

Plastic pollution is a growing issue, with over 10 million tonnes enterithng oceans each year—a figure that could reach 60 million tonnes by 2030. This accumulation affects marine life severely, as larger animals can become entangled in waste while smaller creatures, like hermit crabs, may find themselves trapped in containers. With this technology, researchers aim to mitigate such impacts by helping clean-up teams locate high-risk areas more accurately.

Testing and Validation of the BPDI

The report further highlights that the BPDI’s effectiveness was tested with plastic targets placed on a beach in Gippsland, Victoria. Results were then compared with three existing indices, with the BPDI outperforming them in detecting plastic. Dr. Mariela Soto-Berelov, a co-author of the study, highlighted the technology’s potential to monitor even remote beaches. “The beauty of satellite imagery is its ability to cover vast areas regularly, which is essential for understanding where debris is accumulating and for planning effective clean-ups,” she stated.

Moving Toward Practical Applications

The BPDI shows immense promise but further testing in real-world scenarios is necessary. The RMIT team is now seeking partnerships with organisations to expand their research and help safeguard vulnerable coastlines. Dr. Guffogg, who pursued this research as part of her PhD, is optimistic about its potential to drive local clean-up initiatives. Accurate data could help communities to take active roles in maintaining cleaner shorelines and raise awareness about plastic pollution.

Global Potential for Environmental Protection

The global impact of this tool could be significant as countries work towards international environmental goals. Collaborations with government bodies, NGOs, and environmental agencies could aid in adopting this technology worldwide. Additionally, as the BPDI technology advances, it may be adapted for other ecosystems affected by plastic pollution, broadening its role in environmental conservation efforts. Through innovations like this, the world moves closer to a sustainable future where plastic pollution can be effectively monitored and managed.