A good number of the population believes that a dinosaur-killing asteroid may hit the Earth sometime in the future. But some say it's not just the asteroid people need to fear but comets as well.

Apparently, comets are more dangerous compared to asteroids due to their size and velocity and the element of surprise. Recent reports circulated that NASA warned about an 'extinction level' comet.

"Comets have largely been ignored by people that are interested in defending the planet," Joseph Nuth, a NASA scientist said in a statement. Nuth, a NASA scientists from the Goddard Space Flight Center warned the public about what comets are capable of in a conference.

"Comets have largely been ignored by people that are interested in defending the planet," Nuth said during the American Geophysical Union (AGU) conference held last. Dec. 12.

He discussed that the attention-deprived issue is due to man's incapacity to react to an incoming comet if there will be any. This is due to the limitation of tracking and detecting systems available that don't work on comets yet. He also added that if there are other technologies available now, it would still be insufficient.

"A comet comes out of nowhere, pretty much," Nuth said in a statement. Nuth said that although comets are rarely seen near Earth, Comet Siding Spring was spotted near Mars in 2014 after it was discovered in 2013.

This means comets are surprising making them more hazardous than asteroids. It was capable of bringing what was referred to as "extinction-level" disaster. Because of their stealth movements, detection and deflection efforts will be futile. The NASA scientists also said the size of the comets compared to asteroids are alarming as well. The comets also have faster velocity compared to asteroids. For example, the comet that zoomed pass Mars was moving at 125,000 mph (2000,000 km/h) compared to average NEA speed of 44,700 mph (71,940).

Nuth said he wanted to sound the alarm despite the fact that comet impact is very rare; it would be more devastating than an asteroid impact. The scientists say that the only possible solution to this pressing issue is to hasten reaction time when in case an ongoing comet is spotted.