A NASA researcher warned that comets can actually be more dangerous than near-Earth asteroids. According to the research, comets are more mysterious than asteroids and can actually hit the planet with little to no warning.
Comets are giant icy balls in space that are mainly composed of frozen gas, rocks and dust particles. Unlike asteroids that pass near Earth, comets are known to orbit near the Sun and occasionally inhabit the outer regions of the Solar System.
Asteroids Vs Comets
According to Joseph Nuth, a researcher from NASA's Goddard Space Flight Center, comets are often ignored when Earth-ending scenarios are being discussed. Usually, in these types of conversations, most people tend to focus on how dangerous asteroids can be.
"Comets have largely been ignored by people that are interested in defending the planet," Nuth said during a previous American Geophysical Union meeting according to Space.com.
Nuth explained that one of the main reasons why members of the public, as well as the scientific community, are more interested in asteroids is simply because not much is known about comets. Since asteroids are known to regularly approach Earth, space agencies are able to detect them easily and collect more information about them.
What Makes Comets Really Dangerous
Unfortunately, the mysterious nature of comets is the reason why they are more dangerous than asteroids. Unlike asteroids, comets orbit within the dark edges of the Solar System. This means that they can remain undetected and hidden for a long period of time. Because of this, it's possible that Earth could get hit by a comet without any warning. "A comet comes out of nowhere, pretty much," Nuth said.
Aside from this, comets are known to have massive sizes. While some have kilometre-long diameters, there are other comets that are as big as mountains and even small towns. For instance, the famous short-period space rock Halley's Comet, which becomes visible from Earth every 75 years, has a mean diameter of 11 kilometres.
Impact Event Caused By Comets
Due to the massive size of comets, they are certainly capable of triggering extinction-level events on Earth if they end up colliding with the planet. Although asteroids are made up of harder materials than comets, the combination of the latter's size and velocity makes them a serious threat to Earth.
If a space rock as big as the Halley's Comet hits the planet, Earth would go through the same catastrophic events that led to the extinction of the dinosaurs millions of years ago. In addition to the massive energy that will be released from a comet's impact, the planet will also experience a nuclear winter that can last for decades or even longer.