What could be more frightening than an asteroid hurtling towards the planet? An asteroid that's bigger than the Empire State Building.

A peanut-sized asteroid was discovered by a giant radio telescope in Puerto Rico. Its size suggests the potential hazards it entails, good thing it wasn't moving towards the planet.

The Arecibo Observatory radio telescope built inside a Puerto Rican sinkhole spotted the space rock. The said telescope was built to detect signals for aliens, according to Business Insider.

With its powerful radar station, the telescope is also capable of detecting passing objects by their ping and, in turn, film the echoes created by the moving object. Due to the size of the asteroid, it was easily detected by the Arecibo Observatory radio telescope. The telescope managed to capture a stunning video of the asteroid when it passed by the planet. With the help of the telescope, experts were able to conclude that the asteroid is shaped like a giant peanut.

Experts say that asteroid 2015 BN509 is bigger than New York's Empire State Building. The asteroid just flew passed by the planet in the first week of February moving as fast as 44,000 mph. Its closest distance to Earth is about 14 times the space between the planet and the moon, according to a report.

BN509 is dangerous with its size at 200 meters (660 feet) wide and 400 meters (1,310 feet) long. Although it missed the planet, some believe that it could still hit the Earth in the future. Due to the newfound use of the 1,000-foot-wide Arecibo Observatory radio telescope, some suggest that it could be the Earth's defense from a killer asteroid, according to Wired.

NASA is also working towards securing the planet from alarming asteroid strikes. Last year, the OSIRIS-REx mission was launched to retrieve rock samples and perform surface mapping that will enhance the Earth's asteroid-detecting capabilities that could save lives in the future.