Asteroids can bring tsunamis, shock waves and flattening winds that could be catastrophic. The space rocks approach towards the Earth due to the gravitational forces that affect them. It is worth mentioning here that a car-sized asteroid (space rock) slams into the Earth's atmosphere about once in a year. On the other hand, an asteroid large enough to threaten the existence of life on Earth arrives once in every few million years. According to a report published by spacetelescope.org, there are more than 7 lakh asteroids that have been found in space. About 66 million years ago, a gigantic asteroid (space rock) collided with Earth, creating an explosion over 6,500 times more powerful than the nuclear bomb the US dropped on Hiroshima. The impact sent clouds of debris and sulphur into Earth's atmosphere, blocking the sun's light and warmth for about two years. Photosynthesis ground to a halt, which meant no more plant growth and due to which surviving dinosaurs starved to extinction. It is to be noted that an international team of scientists found that a collision in the asteroid belt 470 million years ago diversified life on Earth. Strange, isn’t it?
According to a study published in the journal Science Advances, the breakup of a major asteroid between Jupiter and Mars filled the entire inner solar system with huge amount of dust. However, the dust led to a unique ice age and, subsequently, to higher levels of biodiversity.
The study further stated that the blocking effect of the dust partially stopped sunlight reaching Earth and an ice age began and the climate changed from being more or less homogeneous to becoming divided into climate zones i.e. from Arctic conditions at the poles, to tropical conditions at the equator. Then, the high diversity among invertebrates came as an adaptation to the new climate.
A team of scientist also detected extraterrestrial helium isotopes that was incorporated in the petrified sea floor sediments in southern Sweden, since the asteroid dust, on its way to Earth, was enriched with helium when bombarded by the solar wind.
However, few scientists proposed that it would be possible to place asteroids, much like satellites, in orbits around Earth so that they continuously liberate fine dust and hence partly block the warming sunlight, a method to cool the planet in an era of global warming.
Birger Schmitz, Paper’s lead author and a professor of geology at Lund University, said, "Our studies can give a more detailed, empirical based understanding of how this works, and this in turn can be used to evaluate if model simulations are realistic."