As the largest asteroid of 2022 flew past the Earth on May 27th, the question arises: what are asteroids, how are they formed and why do so many of them approach so frightfully close to our planet? NASA reveals the truth.
Last week, we witnessed the largest asteroid of the year 2022 make its way very near Earth and then fly past. The Earth is approached by an asteroid almost every other week. In fact, there are around 20,000 asteroids that cross the path of the Earth at some point. The world of asteroids is a curious one but we never really delve deep into it. But as we hear more and more about these asteroids, some very basic questions need to be answered. And who better to help us understand these space rocks than NASA itself. So, let us find out what are asteroids and why are there so many of them and what brings them frighteningly close to Earth. Also read: What is a meteor shower, and the difference between meteor, meteoroid and meteorite? NASA folds
what are asteroids
According to NASA, asteroids, which are also called minor planets, are rocky, airless remnants left over from the early formation of our solar system about 4.6 billion years ago. Asteroids revolve around the Sun just like the planets and that is why they are referred to as minor planets. Some of the well known asteroids include Ceres, Vesta, Pallas, Hygiea, Europa, Davia, Sylvia and others.
How are asteroids formed
As mentioned above, asteroids are early formations of our solar system. As per our present knowledge, asteroids are formed through two different processes. First, the large amount of dust particles in the universe can often come together and due to high gravity zones they stick together creating rocky structures. Second, early asteroids often hit different planets and moons and would chip away parts of the planet. These broken fragments would become asteroids too. Also read: Shocking! A supermassive black hole is lurking within our Galaxy, says NASA
What is the asteroid belt
The asteroid belt is a region of space between the orbits of Mars and Jupiter where most of the asteroids in our Solar System are found orbiting the Sun. The asteroid belt is estimated to contain between 1.1 and 1.9 million asteroids larger than 1 kilometer in diameter, and millions of smaller ones. While the exact reason why there are so many asteroids in the asteroid belt is not known, there are hypotheses for it. One of the popular theories suggests that the zone was a nebular zone where a cloud of interstellar dust and gas collapsed under the influence of gravity of Jupiter and the Sun. With high density of mass, the dust kept combining and getting destroyed repeatedly resulting in the present asteroid belt.
Why do so many asteroids come near to the Earth
According to NASA, the majority of near-Earth objects (NEO) come from the inner part of the asteroid belt. Oftentimes, Jupiter and the Sun’s gravitational pull are not in sync, resulting in asteroids jumping to a new orbit which crosses paths with the Earth orbit. Every once in a while these asteroids and the Earth are positioned close to each other when passing and that’s why we feel the asteroid is approaching the Earth.
But whenever the asteroids come close to the Earth, there is a risk that the Earth’s gravitational pull can overpower the Sun and Jupiter’s pull and can cause the asteroid to crash into the Earth’s surface. According to a report by NASA, small asteroids strike the Earth every day but they are so small that they never make it to the surface and burn in the atmosphere itself.