Unexpected Snowfall in the Chilean Desert Pushes ALMA Telescope into Emergency Mode
In the remote expanses of South America, within the vast and arid Atacama Desert renowned for its extreme dryness and minimal rainfall, an extraordinary natural phenomenon took place—snowfall covering this otherwise parched landscape. This unprecedented event particularly affected the ALMA (Atacama Large Millimeter/submillimeter Array) radio telescope, one of the world's most powerful astronomical instruments, situated at over 5000 meters altitude and used in cutting-edge space observations. On the evening of June 26, the region was unexpectedly struck by a significant snowfall—an unusual occurrence for a location where annual precipitation typically ranges from just 1 to 15 millimeters. This rare atmospheric anomaly compelled the ALMA facility to halt scientific operations temporarily. Safety protocols were activated, putting the observatory into a 'survival mode' which involved ceasing all activities and orienting the antennas towards the wind to mitigate snow and wind loads. Temperatures in the vicinity dropped to –12°C, with wind chill making it feel as cold as –28°C. The storm persisted for several days, hampering the resumption of observation schedules. According to official reports from ALMA, the antennas and associated equipment remain under a 'standby' mode pending safety inspections. Once the storm subsides, teams will initiate the cleanup of the equipment and conduct visual inspections of each antenna. This is critical because the best observational conditions are typically achieved following such weather events, characterized by low temperatures and humidity. Meteorologists from the University of Santiago explain that this unusual snowfall resulted from rare atmospheric instability triggered by a passing 'cold core' system. Such phenomena often occur during the southern hemisphere winter, driven by moist air masses from the Pacific Ocean, but are usually confined to higher altitudes. The occurrence at 3000 meters elevation is exceptionally rare, even for this region. Meanwhile, the storm, with winds reaching 100 km/h, caused landslides, flooding, and power outages across the region. Schools temporarily closed, and local authorities responded to these challenges. This marks the first time in nearly a decade that such severe weather has affected the Atacama area. As soon as the storm ends, ALMA teams will begin meticulous cleaning and inspection procedures to restore full operational capacity. Experts emphasize that although the direct link between such weather anomalies and climate change remains under scientific investigation, climate models increasingly predict more frequent and intense precipitation even in the driest zones. The long-term resilience of astronomical infrastructure in the face of growing climatic variability is becoming a pressing issue. Through observations with ALMA, scientists continue to gather unique data on galactic collisions that occurred over 11 billion years ago, revealing how one galaxy destroys another with powerful quasar emissions that disrupt star formation in neighboring clouds.