Astronomers think they have discovered a new potential source of dangerous asteroids among the famous Taurid meteor shower family. Researchers think that several large objects belonging to this group are yet to be discovered.
In a paper accepted for publication in Astronomy & Astrophysics, European researchers from the Czech Republic, Austria, and the Slovak Republic looked at the unusual behavior of the Taurid meteor shower. This spectacle happens every October and November, and while it is consistent, it’s usually nothing spectacular. But in certain years, its activity increases and astrophiles can see more shooting stars.
The reason for the unusual behavior, they argue, is a second, new branch of debris that is in a resonance orbit with Jupiter. For every two full orbits of the gas giant, these space rocks go around the Sun seven times. While this interaction is regular as clockwork, it previously appeared a bit weird from Earth.
The research is based on 144 Taurid meteors observed by the European Fireball Network in 2015. That was a year of enhanced activity for the Taurids. Astronomers were able to confirm the orbits of 113 of these space fragments, which appear to originate from the same location.
This in itself is an intriguing discovery, but the scientists also argue that two recently discovered asteroids, 2015 TX24 and 2005 UR, are part of this new branch. Both objects are between 200 and 300 meters (650 and 980 feet) in diameter, so there might be objects a few tens of meters in diameter waiting to be discovered. The team estimate that these objects could weigh thousands of kilograms, but that they are actually quite fragile. Still, their fragility doesn’t make them much less of a threat.
“Since asteroids of sizes of tens to hundreds of meters pose a threat to the ground even if they are intrinsically weak, impact hazard increases significantly when the Earth encounters the Taurid new branch every few years,” the researchers wrote in the paper.
The Tunguska accident and the Chelyabinsk meteor are two known example of bolides that didn’t reach the surface in their original size (or possibly at all) and yet were able to have quite an impact. Chelyabinsk was just 20 meters (65 feet) in diameter and mostly burned in the atmosphere, with the shockwave braking windows and resulting in the hospitalization of thousands of people. We don’t know how big the original rock that fell on Tunguska was, but it knocked down 80 million trees in an area of 2,150 square kilometers (830 square miles).
The researchers are not trying to be doomsday preachers, but they are reminding us that there are many dangerous objects out there in space.
