An un-monitored centaur comet may pose a bigger threat to planet Earth than any asteroid out there, scientists say.
In a study from the Royal Astronomical Society – released December 22 – scientists wrote that a much greater concern for the astronomers to monitor should be comets, even if the likelihood of them colliding with Earth is pretty slim (at least in our lifetime).
Scientist focused on a type of comet known as centaur, which is composed of silicates and volatile ice, and it is quite unstable since it approaches or crosses the orbits of several giant planets (or just one).
According to the authors, these types of comets can be 100 times larger than the asteroids that are closer to our planet, and about every 30,000 years they cross Earth’s orbit – that is 100 times more frequent than the possibility of an asteroid impact.
Bill Napier, co-author of the study and honorary professor at the Buckingham Centre for Astrobiology at the University of Buckingham, said that there is a need to track celestial objects other than asteroids in our immediate neighbourhood to foresee the risk of possible impacts. Astronomers should look beyond Jupiter’s orbit to find the centaurs, because these distant comets could pose a great danger.
The claim that the Spaceguard programme of the National Aeronautics and Space Administration (NASA) has discovered 93 to 95 percent of near-Earth objects (NEO) that are larger in size than one kilometre, is only justifiable as long as the NEOs are only asteroids in short-period orbits, and not comets or other asteroids, the authors of the study said.
Comets and asteroids do not have an unobstructed orbit around the sun, like planets do, this being a reason why they do not classify as ‘planets’. Pluto lost its tile of ‘planet’ because of this reason (among other reasons).
Around 2,350 BC, Earth may have been hit by a centaur, scientists say. It is estimated that once every 40,000 to 100,000 years, a centaur crosses our planet’s path. Fortunately for us, there are currently no signs of a centaur would appear to be heading towards Earth, astronomers say.
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