comets

Not Just Asteroids, Comets Are A Threat Too Says NASA Scientist Who Said The Earth Is ‘Due For An Extinction Level Event’

Earlier this week, a senior NASA scientist was in the news after he warned about the earth being supposedly due for an extinction level event. The scientist, Joseph Nuth works at NASA’s Goddard Space Flight Center as a scientist for Primitive Bodies, and was attending the annual fall meeting of the American Geophysical Union (AGU), where he talked about these threats that have the capability to cause an extinction level event.

When Joseph talked about these celestial threats, most publications automatically assumed he was talking about the most common suspect – asteroids. However, in a very recent article on Space.com Nuth reveals that like most scientists, even people from his own science community seems to have underplayed the threats from a comet – which could be potentially, even more, deadlier than most asteroids out there. According to Nuth, apart from policymakers, scientists too, should start taking measures to combat the threat posed by comets.

Attack of asteroids on Earth
[Image by muratart/Shutterstock]

“Comets have largely been ignored by people that are interested in defending the planet,” says Nuth.

According to Joseph, one main reason for the comet being overlooked in favor of the asteroid is the existing perception that unlike an asteroid which can be easier to detect and possibly destroy, a comet would be almost undetectable and close to being unstoppable. He, however, goes on to add that unlike popular perception, it is still possible that we could be able to save our planet from a comet strike – only if we are prepared for such an eventuality.

Before we move further, we should make sure we figure out the differences between a comet and an asteroid.

Comets vs Asteroids. The Differences

In case you are still wondering what the difference really is between an asteroid and a comet, here is brief lowdown. To start with, you should understand that one reason for us to be more concerned about an asteroid is the fact that most asteroids revolve around the sun in orbits that are much closer to Earth. This is not the case with comets which tend to revolve very far out in our solar system, in log elliptical orbits. This makes a possible encounter with an asteroid much more likely than a comet. Another major difference is that asteroids are rocky in nature – unlike comets that are made of a combination dust, ice, and rock. Most comets are identified by their long tails – which is created when material from its surface vaporizes as it approaches the sun.

Comet bulgaria
[Image by Petar Petrov /AP Images]

According to Joseph Nuth, asteroids that are close to the orbit of the earth (near-Earth asteroids or NEAs) are much easier to detect and keep track of – compared to comets.

“A comet comes out of nowhere, pretty much,” Nuth warns. This is just one reason that makes comets potentially deadlier than an asteroid.

He also cited a recent example. Back in January 2013, a 0.3-mile wide comet which was named Comet Siding Spring was discovered. 22 months later, in October 2014, this very comet went past Mars – the closest planet to earth. At its closest, it was just 87,000 miles (140,000 km) from Mars – which in celestial terms, is way too close for comfort. What was more worrying was the fact that in spite of being detected early, scientists were caught unaware about its close call with Mars.

Nuth also adds that unlike asteroids that could potentially hit the earth at 44,700 mph (71,940 km/h), comets could travel more than twice as fast with speeds of up to 125,000 mph (200,000 km/h). Thanks to the increased speed, even smaller comets can pose some serious threat and cause greater damage. Now that we have mentioned size, he also adds that your typical comet tends to be on average larger in size than an asteroid.

In the eventuality of a successful detection of a comet hurtling towards the earth, the procedure to prevent a direct hit would be similar to that of meteors. However, unless policymakers and scientists do not come forth with a solid plan, we all continue to remain vulnerable.

[Featured Image by Geralt/Pixabay]

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