Imagine standing on the roof of the world, where the air is thin and the stars feel close enough to touch. This is Daocheng, a remote county in Southwest China's Sichuan province, where scientists are unraveling the universe's deepest secrets. But here's where it gets controversial: could this isolated region hold the key to understanding cosmic rays, black holes, and even the birth of neutron stars?
Perched atop Haizi Mountain, at a staggering altitude of over 4,400 meters, the Large High Altitude Air Shower Observatory (LHAASO) stands as a silent guardian of the cosmos. Spanning 1.36 square kilometers of ancient glacial terrain, this intricate network of detectors resembles a colossal, high-tech spiderweb, tirelessly capturing traces of cosmic rays—subatomic particles that travel across the universe, carrying secrets from distant stars and galaxies. These rays, invisible to the naked eye, are one of the three primary messengers (alongside electromagnetic and gravitational waves) that allow us to observe the universe. Yet, despite their discovery over a century ago, their origins and acceleration mechanisms remain one of astrophysics' greatest enigmas. And this is the part most people miss: LHAASO was built specifically to crack this mystery.
This month, LHAASO made headlines with a groundbreaking discovery. It provided crucial evidence that black holes, while devouring material from their companion stars, act as powerful particle accelerators, potentially playing a pivotal role in producing high-energy cosmic rays in the Milky Way. But does this mean black holes are not just destroyers, but also creators? The debate is far from over, and scientists are eagerly analyzing the data.
Not far from LHAASO, another marvel of modern science quietly tracks the sun. The Daocheng Solar Radio Telescope, the world’s largest circular array of its kind, monitors solar activity with unparalleled precision. Its mission? To improve space weather forecasts, which are critical for protecting satellites and communication systems. As chief designer Yan Jingye explains, 'When the sun 'sneezes,' the Earth's space weather can 'catch a cold,' potentially disrupting our technology.' In September 2023, the telescope accurately predicted a solar storm's arrival within an error margin of less than 1.16 hours—a feat that could revolutionize how we prepare for space weather events.
Daocheng's unique advantages—high altitude, flat terrain, minimal light pollution, and strong local support—have transformed this sparsely populated county (home to just 30,000 people) into a powerhouse of deep-space exploration. But is this rapid development sustainable? As more facilities are built, how will the region balance scientific progress with environmental preservation?
Amidst this scientific renaissance, the human story is equally compelling. Cao Zhen, chief scientist of LHAASO, recalls the early days of site selection in 2014: 'We slept in tents, listening to wolves howling nearby. It was both terrifying and exhilarating.' Today, Cao routinely flies to this high-altitude outpost, overseeing the expansion of LHAASO's capabilities. A new tracking system, featuring 32 Cherenkov telescopes, is being added, akin to 'giving LHAASO hawk eyes,' as Cao puts it. This upgrade will improve its spatial resolution fivefold, allowing scientists to observe cosmic phenomena with unprecedented clarity.
International collaboration is at the heart of LHAASO's success. On October 9, 2022, it detected the brightest gamma-ray burst ever recorded—an event caused by a dying star 2 billion light-years away. While other global detectors were overwhelmed by the intensity, LHAASO captured the entire event, collecting over 60,000 gamma-ray photons. 'LHAASO is revolutionizing our understanding of the Galaxy,' says Italian astrophysicist Elena Amato. With partners from France, Russia, Thailand, and Pakistan, LHAASO exemplifies China's growing leadership in international big science projects. But as China takes the lead, how will global collaboration evolve? Will it foster unity or spark competition?
As Daocheng continues to attract cutting-edge facilities—including a 2.5-meter-wide-field solar telescope set to be the world's largest upon completion in 2026—it is clear that this remote region is becoming a frontier for deep-space exploration. 'This place is a hotbed for science,' Cao declares. But as we gaze at the stars, we must also ask: What mysteries will Daocheng unveil next? And how will these discoveries reshape our understanding of the universe? The answers may lie in the cosmos, but the questions are ours to explore—together.
