What Is An Asteroid?

The first thing that might come to mind when you think of an asteroid floating about in the cosmos is science fiction. It’s pretty easy to picture the Millenium Falcon blowing one to smithereens. With that said, these massive objects are a huge part of our universe, though they are actually quite small in relativity to the rest of the entities in space.

Astronomy describes asteroids as little rock objects in space that orbit around the sun. Though they share the same orbiting characteristics as planets, they are much smaller. There are millions of asteroids within our own solar system, though the majority of them move within the asteroid belt, which is a large region of space between Jupiter and Mars. 

In terms of formation, asteroids have been around for billions of years. They are said to be left over pieces of the inception of our solar system, which came into creation about 4.6 billion years ago after a massive collapse. While most of the material joined forces to create the center of our solar system, aka the sun, as well as most of our planets, there were some leftover portions that hung around without ever joining a larger, planetary mass. 

Not all asteroids are the same. In fact, asteroids are a bit like snowflakes, as we have yet to find even two that are exactly alike. Most asteroids have jagged, irregular shapes, though a lot of people assume that they are all round like planets. Asteroids can be anywhere from hundreds of miles in diameter to the size of a rock on the ground in your backyard. In terms of material, asteroids are typically made out of a variety of different elements, including nickel and iron. Some even have clay!

When Were Asteroids Discovered?

Asteroids were discovered in 1801 by an Italian astronomer and priest named Giuseppe Piazzi. He discovered Ceres, one of the largest asteroids known to man, as it was orbiting on the belt between Jupiter and Mars. Ceres is now classified as a dwarf planet, as it is about a quarter of the mass of every single asteroid in the belt put together. 

The word “asteroid” was not actually the name until 1802, when William Herschel wanted something a bit different to classify them by instead of “minor planets”, which many scientists referred to them at the time. It comes from an old greek phrase that means “star-like”.

Biggest Asteroid Known to Man

It is difficult to classify the largest asteroid, as the three largest ones out there, Ceres, Vesta, and Pallas, are actually classified as protoplanets. This is because they share many of the same characteristics with planets in our solar system. The largest asteroid that resembles other asteroid on the belt is known as Hygiea. This asteroid, much like others on the belt, has an interior that is undifferentiated. While Ceres is the largest by a long shot, the fully ellipsoidal shape technically makes it a dwarf planet.

Asteroid Fun Facts

NASA scientists believe that the only reason we are alive and well on Earth today is because asteroids collided into each other millions of years ago. They say that the origin of life can be accredited to the massive flux of asteroids and comets that smashed into each other, forming the Earth. As comets continued to collide, the small materials that were deposited helped life to form. These collisions helped to deliver water and ice, as well as molecules with carbon bases. 

There are a number of asteroids out in space that scientists believe are potentially hazardous. These asteroids are characterized by the fact that they could easily collide with our planet in the next few decades. Scientists also note that we should not worry if an asteroid is on a collision course set for the next 30 or 40 years, as we will be able to react to it thanks to new technology. There are many possibilities for avoiding a collision, including blowing up the asteroid or diverting it in its path.

How Far Is The Nearest Asteroid?

Because asteroids are constantly orbiting at a different speed than the Earth, there are actually multiple asteroids that are most near to us. The last time we measured was January 6, 2019. Scientists found that there are about 19,363 asteroids that are near Earth, though only around 2,000 of them are classified as “potentially hazardous”. 

These asteroids have fairly limited lifetimes compared to the lifetime of our solar system, as they are usually eliminated in just a few million years through collisions or solar system ejection.

Latest In Asteroid News

In the latest asteroid news, scientists have found a potentially hazardous asteroid that is the size of the Empire State Building. On August 10, 2019, the asteroid will come incredibly close to the Earth, though NASA says that we shouldn’t worry, as it should pass by without an incident. It is classified as a “near-Earth” asteroid, meaning it is within 30 million miles of our planet’s orbit. This particular asteroid is set to fly by about 4.5 million miles from our planet with a whopping speed of 10,400 mph.

In other news, scientists say that asteroid mining could be a new ticket for wealth. With precious and rare Earth metals such as gold, nickel, platinum, cobalt, and more, asteroids are a bit like planetary treasure chests. While we’ve seen it in science fiction for decades now, it is finally becoming a possibility. There are now a few major companies out there that are messing with the idea of starting asteroid mining programs. The major question is,

Should we even be doing this? 


Asteroids have given us life and they will likely be the things that destroy when they eventually come pummeling through Earth. It is up to us to respect them and learn about them so that we can attempt to avoid the unavoidable.