Wednesday 4th September around the 18:46 Italian time a very bright green bolide was spotted off the coast of Philippines which, after a few moments, is explodedThis is the asteroid 2024 RW1an asteroid on a collision course with the Earth which fortunately, given its small size of one meter, burned up harmlessly in the Earth’s atmosphere without causing damage, returning at the speed of 75,000 km/hThe asteroid was discovered only at the last moment, on the morning of September 4, by the researcher Jacqueline Fazekas who works on the project Catalina Sky Surveyfunded by NASA for the identification of precisely these objects potentially dangerous for our planet. The projections of ESA gave the asteroid’s re-entry point as the western Pacific Ocean, near the island of Luzon in the Philippines. The news then spread rapidly, also thanks to the alert issued by the website ANASA’s Steroid Watch who predicted that the impact could create a bolide, a fireball visible from the eastern coast of the Philippines. This has led to many videos on social media showing the asteroid entering and destroying the atmosphere.
What kind of object is 2024 RW1?
2024 RW1 It was only discovered at the last moment on the morning of September 4th from the astronomers of the Catalina Sky Survey. This is a small asteroid having 1 – 1.5 meters in diameter which entered the atmosphere at the speed of 75,000 km/h.
Friction with the atmosphere caused the asteroid to begin to burn on the way backthus becoming a meteor and appearing as a “shooting star” of greenish color. Color is an important parameter as it indicates the presumed chemical composition of the asteroid: the magnesium present in an asteroid, for example, can create a blue-green hueswhich is the one visible in the video. However, the brightest meteors, also called racing carsoften leave a glowing tail in an atmosphere that is initially green due to the neutral oxygen in the air, but which then becomes the color of the elements the meteor was made of.
From the videos circulating online it is still difficult to establish with certainty whether the greenish color is due to the chemical composition of the asteroid or to atmospheric atoms.
The importance of systematic asteroid searches
Objects as small as 2024 RW1 are difficult to spot. Many of them they never get discoveredre-entering the atmosphere over uninhabited areas or the ocean, thus remaining forever unknown. It is therefore great news that warning systems, such as the Catalina Sky Surveyare becoming increasingly sensitive enough to be able to identify such small objects. According to ESA, this is in fact only the ninth asteroid of this type spotted before impact.
The improved sensitivity means that you can not only detect small and close objects, but especially those big and far away which fall into the category of potentially dangerous asteroids. This term refers to those objects that have an orbit that takes them to a close encounter with Earth and which have such dimensions (above 100 meters) to cause significant damage in the event of an impact, surviving atmospheric reentry unscathed. Projects such as the Catalina Sky Survey They therefore serve to identify these potentially dangerous asteroids on a collision course with Earth several years before they can actually collide with our planet.
At the moment we do not have the technology necessary to deflect objects of such a size as to cause a catastrophic event for human life, and this is why almost all the space agencies in the world are working on planetary defense projects. For example, we had NASA’s DART mission, which crashed a probe into a system of double asteroids in an attempt to change their trajectory. NASA is also designing a new infrared telescope known as NEO Surveyor to detect potentially dangerous asteroids by exploiting their infrared emission, while China is developing its own mission to deflect an asteroid by 2030.
