On September 4, 2024, astronomers detected a small asteroid, 2024 RW1, just hours before its predicted atmospheric entry over the Philippines.
The asteroid, roughly 1 meter (3 feet) in size, was spotted by Jacqueline Fazekas of NASA’s Catalina Sky Survey in Arizona only eight hours before impact. This discovery marks only the ninth time that an asteroid has been detected pre-impact, showcasing significant advancements in asteroid tracking and planetary defense.
The European Space Agency (ESA) confirmed that 2024 RW1 would enter Earth's atmosphere at approximately 12:46 p.m. ET (16:46 UTC) and burn up harmlessly over the western Pacific Ocean near Luzon Island. Residents in the Philippines were advised to look out for a bright fireball, although tropical storm Yagi may obstruct visibility.
Discovery and the Importance of Planetary Defense
The late discovery of 2024 RW1 is a milestone for the ongoing efforts to detect and track near-Earth objects (NEOs). Although the asteroid poses no danger due to its small size, its detection highlights the improving capabilities of systems like the Catalina Sky Survey. "We’re getting better at spotting asteroids before they hit us," an ESA spokesperson said, referencing the asteroid's rapid discovery just hours before impact.
While larger, more dangerous asteroids have been the focus of planetary defense initiatives, events like this one illustrate how even small space rocks can be tracked in real-time. NASA’s Asteroid Watch program and ESA’s planetary defense teams are actively monitoring space for more significant threats. In a tweet, NASA Asteroid Watch noted, "2024 RW1 is no threat but gives us another opportunity to refine our detection techniques for future NEOs."
Impact Predicted Over the Philippines
According to ESA’s projections, 2024 RW1 will enter the atmosphere at around 12:46 p.m. ET (16:46 UTC), resulting in a bright fireball over Luzon Island. Though tropical storm Yagi may limit visibility, those in the region could still witness a stunning celestial event. The asteroid will disintegrate harmlessly, leaving no threat to people or property. ESA shared an impact prediction map via social media, showing the exact area of atmospheric entry.
⚠️☄️Incoming!
A roughly 1 metre asteroid will strike Earth’s atmosphere over the Philippines near Luzon Island at 17:08 UTC today, 4 September.
The object is harmless, but people in the area may see a spectacular fireball!
Discovered this morning by the Catalina Sky Survey,… pic.twitter.com/UjQLbh3fFr
— European Space Agency (@esa) September 4, 2024
This kind of event is known as a bolide, where a small asteroid creates a bright fireball in the sky as it burns up. The International Meteor Organization (IMO) noted that this fireball event could also lead to potential meteorite recoveries in the area. "We expect a dramatic and scientifically valuable event," the IMO stated, encouraging observers to report sightings to its network.
A Rare and Valuable Event
This marks only the ninth known instance of an asteroid being detected before its impact, making the event significant in the field of planetary defense. Astronomers and planetary scientists have long worked on improving early detection systems to better monitor potential asteroid threats. NASA’s Catalina Sky Survey is one of the key observatories scanning the skies for small, fast-moving objects like 2024 RW1.
The detection of this asteroid is part of broader global efforts to ensure that larger asteroids—those capable of causing widespread damage—are detected long before potential impacts. ESA and NASA have invested heavily in missions like the DART mission and upcoming NEO Surveyor, both of which are designed to detect and, if necessary, deflect hazardous objects before they reach Earth.
"Small asteroids like this serve as a test for our global network," ESA shared on Twitter, noting that 2024 RW1 provides an opportunity to refine techniques for spotting and tracking these near-Earth objects.