In the early morning at about 5am on 12 February 2020, a bright object was seen in the sky. It blazed over Singapore and Johor Bahru, Malaysia, and its lights were caught on two dash-cam videos. The video that was filmed in Singapore was captured near the Nanyang Technological University campus, next to the Jalan Bahar flyover.

When an object enters the Earth’s atmosphere and burns up on entry, the way we name it depends on how big it is, as well as how bright. For example, an asteroid is a piece of rocky, iron, or icy debris, over...

Singapore, unlike Japan, does not have any volcanoes. However, our little sunny island is in proximity to 127 active volcanoes in Indonesia and 53 in the Philippines. This means that like Japan, Singapore too could be significantly affected by different types of volcanic hazards, making research on volcanoes an important area of study for both countries. Here’s how Singapore was once affected.

Singapore was impacted by volcanic ash in 1991 after the eruption of Mount Pinatubo in the Philippines. And with that many volcanoes around the country, it is unlikely to be a one-off. As for Japan, it is in constant alert with its currently 110 active volcanoes. But, despite a very developed monitoring system, some eruptions – such as the 2014 Ontake eruption – still have...

During the early evening of 28 September 2018, a magnitude-7.5 earthquake struck along the coast of northwestern Sulawesi, Indonesia. This region hosts a famous strike-slip fault system called the Palu-Koro Fault.

Even though this is one of the fastest slipping faults in the world, it has not produced many large earthquakes during historical times. The Palu-Koro Fault was therefore thought to have a high probability of a large and destructive earthquake, and so the occurrence of the 2018 quake in Sulawesi wasn’t very surprising.

However, the landsliding that was triggered by the earthquake turned out to be unexpectedly destructive. Soon after the earthquake, witnesses described entire villages south of Palu City sinking into mud and disappearing, and it was...

On 5 July 2019 at 1.33am (Singapore time), a Mw 6.4 earthquake struck the town of Ridgecrest in California. Its seismic waves could be felt from Los Angeles to San Jose. Nearly a day and a half later, on 6 July at 11.19am (Singapore time), a more powerful Mw 7.1 quake struck the same region. Because the Mw 7.1 earthquake is the largest event so far in this sequence, it is considered to be the mainshock. The events leading up to it, which include the Mw 6.4 quake, are considered to be foreshocks.

From this sequence of earthquakes, it is clear that the Mw 6.4 foreshock had triggered seismicity on conjugate faults (i.e. intersecting faults that criss-cross in a X-shape) along the Eastern California Shear Zone which runs somewhat parallel to the San Andreas Fault, but is...