Kronotsky volcano in Kamchatka, Russia, erupted at 03:50 UTC (15:50 LT) on October 4, 2025, ending a century of dormancy. The Kamchatka Volcanic Eruption Response Team (KVERT) reported an explosive eruption with an ash column reaching 9.2 km (30 180 feet) above sea level. Aviation Color Code was raised to Red. KVERT warns that additional ash emissions rising up to 15 km (49 200 feet) remain possible.
A newly-discovered asteroid designated 2025 TF made an extremely close approach to Earth at 00:49 UTC on October 1, 2025, reaching a nominal distance of 0.02 LD (0.00005 AU / 6 790 km / 4 220 miles) from Earth’s center — equivalent to about 419 km (260 miles) above the surface over Antarctica. At this distance, it is now classified as the second-closest asteroid flyby ever recorded.
The interstellar object 3I/ATLAS showed no measurable non-gravitational acceleration between May and September 2025, implying a nucleus mass above 33 billion tons and a diameter larger than 5 km (3 miles), according to a study co-authored by Harvard Professor Avi Loeb and published on September 24.
A large sea surface temperature anomaly has developed in the North Pacific Ocean, extending toward the U.S. West Coast. Forecasts suggest the anomaly could help trigger colder-than-average conditions across central and eastern United States and Canada during the upcoming 2025/26 winter season, with a weak La Niña further reinforcing the setup.
A coronal mass ejection (CME) launched from the Sun on September 19 is forecast by NASA’s ENLIL model to strike interstellar Comet 3I/ATLAS on September 24 or 25, an extremely rare event that comes as the comet brightens 40-fold and prepares to disappear into the Sun’s glare.
At least 12 people died after record breaking rains flooded Kolkata, West Bengal on September 23, 2025, leaving roads inundated, transport paralyzed, and power disrupted.
At least two people died and three remain missing after Matai’an Creek Barrier Lake overflowed twice on September 23, 2025, in Guangfu Township, Hualien County, Taiwan. Nearly 300 people were stranded as floodwaters caused widespread destruction, following early evacuation of about 10 000 residents on September 22.
Super Typhoon Ragasa, locally named Nando, began crossing Calayan Island in Cagayan province, northern Philippines, at around 03:00 UTC (11:00 LT) on September 22, 2025, bringing destructive winds, extreme seas, and life-threatening storm surge. The Philippine weather bureau reported maximum 10-minute sustained winds of 215 km/h (134 mph) and gusts up to 295 km/h (183 mph).
A gravity anomaly recorded by NASA–German GRACE satellites in early 2007 over the Atlantic Ocean points to mass redistribution near Earth’s core–mantle boundary, around 2 700–2 900 km (1 700–1 800 miles) deep. Researchers suggest a perovskite-to-post-perovskite mineral phase change produced decimetric boundary shifts, offering the first evidence that deep mantle processes can unfold within just a few years and potentially affect Earth’s magnetic field.
A very deep partial solar eclipse will occur at 19:43 UTC on September 21, 2025, visible across Antarctica, New Zealand, and parts of southern Australia. At maximum, the Moon will cover up to 85% of the Sun’s diameter, with obscuration reaching nearly 80% of the solar disk.
