New study reveals what really happens to the missing asteroids up there, in our Solar System. An international team of scientists have debunked the theory that asteroids and comets end their existence with a final plunge into the sun. It turns out, they disintegrate long before that.
Asteroids are nothing but small, airless rocky worlds revolving around the sun, that are too small to be called planets. They are also known as planetoids or minor planets. In total, the mass of all the asteroids is less than that of Earth’s moon. But despite their size, asteroids can be dangerous. Many have hit Earth in the past, and more will crash into our planet in the future.
That’s one reason scientists study asteroids and are eager to learn more about their numbers, orbits and physical characteristics. This is how they came up with this new finding regarding the death of these ‘minor planets’. The study may bring us closer to understanding how to protect the Earth from an asteroid strike.
Until recently, scientists believed that the demise of asteroids close to Earth happen in a fiery collision with the sun. But by examining nearly 9,000 near-Earth objects, or NEOs, an international team of researchers have recently found that asteroids and comets crumble long before they reach the surface of the blazing star.
So, it turns out that the asteroids are actually dying a slow death, not unlike humans in their later stages of life, they are simply breaking down.
The team’s work also helps explain several discrepancies between observations and predictions of the distribution of small objects in our Solar System. Meteors are such an object. These are effectively tiny bits of dust and rock dislodged from the surfaces of asteroids and comets that then end their lives burning up as they enter our atmosphere.
Observations and studies have established that meteors often travel in ‘streams’ that follow the path of their parent object. However, in almost all cases astronomers have been unable to match most of the meteor streams on orbits closely approaching the Sun with known parent objects.
What the latest study suggests is that the parent objects were completely destroyed when they came too close to the Sun, leaving behind streams of meteors but no parent NEOs. They also found that darker asteroids are destroyed farther from the Sun than brighter ones.
This case is explained by an earlier discovery that NEOs that approach closer to the Sun are brighter than those that keep their distance from the Sun. The fact that dark objects are more easily destroyed implies that dark and bright asteroids have a different internal composition and structure.
So, brighter asteroids, survive longer than dark asteroids, which absorb more light. And smaller asteroids disintegrate faster than bigger ones.
According to Mikael Granvik, a research scientist at the University of Helsinki and lead author of the study, their new finding allows planetary scientists to understand a variety of recent observations from a new perspective. It also leads to a more profound advance in asteroid science.
Perhaps the most intriguing outcome of this study is that it is now possible to test models of asteroid interiors simply by keeping track of their orbits and sizes.
However, the strange case of the missing asteroids is now solved. Perhaps our world would be far different today if it weren’t for the Sun destroying vast numbers of these space-borne objects.
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