What Are Asteroid?

 

 

What Are Asteroid?

One of the most well-known theories concerning the death of the dinosaurs argues that the ancient creatures went extinct when a large stone from space slammed into Earth. Through a series of events, this ultimately led to the extinction of dinosaurs. You have probably heard countless stories and hypotheses regarding the disastrous consequences of an asteroid strike on Earth, but what exactly are asteroids? Where do they come from? And most importantly, could they really obliterate the entire planet if they were to strike Earth with enough force? An asteroid is a small, rocky object that orbits the sun, just like the rest of the planets and celestial bodies in our solar system. Although asteroids are present throughout the solar system, most of them live in the asteroid belt—a region located between the orbits of Mars and Jupiter. The size of objects within the asteroid belt have a wide range, from being no bigger thana dust particle to almost a thousand kilometers wide. In fact, the largest asteroid present in the asteroid belt—Ceres—is 940 kilometers wide and is considered a dwarf planet. Although the asteroid belt hosts a multitude of asteroids, it’s not the only region where these rocky objects hang around. Some asteroids are also found in the orbits of planets, which means that the planet and the asteroid circle the sun on the same elliptical path. For some, a more interesting question is, how did these asteroids come into being? Our solar system came into existence about4.6 billion years ago when a large cloud of gas and dust collapsed. Following this event, most of that material fell to the center of the cloud and resulted in the formation of the sun—the central star of our solar system. Asteroids vary greatly in terms of their shape and size. An asteroid can be as large as Ceres, nearly thousand kilometers wide. On the other end of the spectrum, the smallest asteroid ever studied is a space rock called2015 TC25.It’s 2 meters wide and was observed when it made a close flyby of Earth in October2015.Almost all asteroids are irregularly shaped, although a few big ones, like Ceres, are nearly spherical. Asteroids are also cratered or pitted, and their surface is thought to be covered induct. Asteroids orbit the sun in elliptical orbits, but additionally, they also rotate, sometimes tumbling haphazardly through space. They may even have their own moons! We know of more than 150 asteroids that have a small companion moon, and some have more than one! Asteroids are found in three main regions of our solar system. A significant amount of asteroids are founding the Asteroid belt, which lies between Mars and Jupiter. Then there are Trojan asteroids—a large group of asteroids that share the orbit of planets around the Sun. Jupiter Trojans are the most well-known and numerous Trojans. The total number of Jupiter trojans larger than 1 km in diameter is believed to be about1 million! Finally, there are Near Earth Asteroids, ornithes circle closer to Earth than the sun. It is believed that nearly 10,000 of all known asteroids are NEAs. Asteroids are known to be composed of clay and rocks, as well as metals like nickel andiron. Now, since some asteroids are very close to Earth, in comparison to other celestial bodies, is it possible for them to slam into our planet? Absolutely! Ever since Earth came into being, it has been struck relentlessly by asteroids and comets. In fact, the most popular theory regarding the extinction of dinosaurs is related ton asteroid that slammed into Earth, causing widespread destruction, obliterating most life forms in the global aftermath. Although many celestial objects approach our planet, a significant number of them get burned up in the atmosphere and never make it to Earth’s surface. According to NASA, space rocks smaller than25 meters will most likely burn up as they enter Earth's atmosphere. However, some larger asteroids do make it through the atmosphere and impact our planet’s surface. In 2013, an asteroid slammed into the atmosphere over the Russian city of Chelyabinsk. The shock wave created by this event injured1,200 people. An asteroid capable of causing a global apocalypse would have to be more than 400 meters wide. Impact from such an asteroid would cause massive destruction of both life and property on a global scale. Fortunately, asteroids that huge strike Earth an average of once every 1000 centuries. All in all, asteroids can and do orbit near our planet, but most will never approach Earth, and even if they do, they usually get burned up in the atmosphere before ever making contact with our planetary surface.