Researchers Observe Extra-galactic Meteor
The common belief is that all meteors come from inside our solar system. Most meteors are thought to be pieces of comet dust or fragments of asteroids that enter Earth’s atmosphere and burn up before they hit the ground, leaving a fiery trail we call “shooting stars.” But a recent observation might put a hole in the idea that these space rocks only come from the immediate vicinity of our solar system. A group of astronomers in Russia believe they observed a meteor of extragalactic origin.
On July 28, 2006, Victor Afanasiev from the Russian Academy of Sciences was making observations using a 6 meter telescope equipped with a multi-slit spectrometer. By chance, he observed the spectrum of a faint meteor as it burned up in the Earth’s atmosphere, and in looking at the data, found several anomalies. First was the speed at which the meteor was traveling. This meteor hit the atmosphere at about 300 kilometers per second, which is quite extraordinary. Only about 1% of meteors have velocities above 100 km/sec, and no previous meteor observations have yielded velocities of several hundred km/s. So where did this one come from?
Since the Earth moves around the galactic center at about 220 km/s, Afanasiev says the meteor’s origin cannot easily be explained by reference to the Milky Way. It appears that it came from the direction in which the Earth and the Milky Way is travelling towards the center of our local group of galaxies. “This fact leads us to conclude that we observed an intergalactic particle, which is at rest with respect to the mass centroid of the Local Group and which was “hit” by the Earth,” Afanasiev and his team say in their paper.